Open Access is an initiative that aims to make scientific research freely available to all. To date our community has made over 100 million downloads. It’s based on principles of collaboration, unobstructed discovery, and, most importantly, scientific progression. As PhD students, we found it difficult to access the research we needed, so we decided to create a new Open Access publisher that levels the playing field for scientists across the world. How? By making research easy to access, and puts the academic needs of the researchers before the business interests of publishers.
We are a community of more than 103,000 authors and editors from 3,291 institutions spanning 160 countries, including Nobel Prize winners and some of the world’s most-cited researchers. Publishing on IntechOpen allows authors to earn citations and find new collaborators, meaning more people see your work not only from your own field of study, but from other related fields too.
To purchase hard copies of this book, please contact the representative in India:
CBS Publishers & Distributors Pvt. Ltd.
www.cbspd.com
|
customercare@cbspd.com
Pomegranate due to its high nutritive and therapeutic value, high antioxidant capacity, and bioactive compounds is known as superfruit. However, its consumption is scarce due to difficulties in peeling and extraction of arils, hand staining and irritation during extraction due to phenolic metabolites in fruits. Improved varieties have excellent flavour with crisp-juicy-dark red, gem-like arils, indicating potentiality for export and value-added products with the extended shelf life. Advances in post-harvest technology had played a vital role in product diversification by keeping original nutritional value. Extensive research has been carried out in the development of various pomegranate-derived products such as minimally processed arils, frozen seeds, RTS juice, concentrates. These processed products are highly acceptable because of their dessert qualities and palatability. Consumers readily pick well-matured big size fruits with attractive colour but low-grade pomegranate is kept out of market. Additional innovative tools like modified atmosphere packaging offer for the optimal use of such lower-grade fruits. Consumers prefer minimally processed pomegranate arils and frozen arils packed in punnets over whole fruit. Juices can be used in beverages and for various treatment purposes. This new sector of pomegranate processing will allow the use of non-commercial pomegranate fruits and improve pomegranate utilization for human health.
Horticulture Section, Rajarshee Chhatrapati Shahu Maharaj College of Agriculture Kolhapur, Mahatma Phule Agricultural University, India
Ravindra D. Pawar
Horticulture Section, Rajarshee Chhatrapati Shahu Maharaj College of Agriculture Kolhapur, Mahatma Phule Agricultural University, India
Sandip S. Patil
Agricultural Extension and Communication, Rajarshee Chhatrapati Shahu Maharaj College of Agriculture Kolhapur, Mahatma Phule Agricultural University, India
*Address all correspondence to: sangram1326@hotmail.com
1. Introduction
Pomegranate has been cultivated in India, South East Asia and tropical continents for thousands of years. Previously pomegranate was not grown as table fruit, but it was grown as decorative plant with its ornamental value, for its red, orange or, occasionally, creamy yellow flowers. Pomegranate is also mentioned in biblical writings and was used as blessings in ceremonies. The pomegranate (Punica granatum L.) belongs to the Punicaceae family. It is a native of Iran to Himalayan region. Pomegranate is also known as the Chinese apple or Apple of Carthage or Apple with many seeds. It is grown in tropical and subtropical parts of the world and is extensively grown in Iran, Spain, India and USA as well as in most Near and Far East countries [1]. It is highly adaptive to the various climates and found to be commercially cultivated in diverse geographical regions including Mediterranean region, Asia and USA. Among all the pomegranate-producing countries across the world, the 76 per cent of the production is contributed by Iran, India, Spain, China, Turkey and USA.
As pomegranate thrives best under hot dry summer and cold winter provided irrigation facilities and can withstand different soil and climatic stresses, it is grown in the arid and semi-arid regions of the country [2]. Pomegranate has high nutritional values and it requires low maintenance cost, has high yielding potential and is tolerant to biotic and abiotic stresses making it popular among growers as well as consumers. It is grown in the foothills of Himalayas along entire hilly tract of Jammu and Kashmir, Himachal Pradesh and parts of Uttar Pradesh. India ranks first in the pomegranate production (28.45 lakh tonnes) in the world, on an area of 2.34 lakh hectares with productivity of 12.16 t/ha [3]. Maharashtra, Karnataka, Gujarat, Rajasthan, Uttar Pradesh, Andhra Pradesh and Tamil Nadu are the major pomegranate growing states in India. Maharashtra, which emerged as a pomegranate basket of India, has 1.47 lakh ha area (63 per cent) under pomegranate cultivation with 62.88 per cent (17.89 lakh tones) of share in total production of the country. Though the country is the largest producer of pomegranate, more than 90 per cent of the produce is utilized for domestic fresh consumption and remaining is exported. India’s share in global exports is around 6.4 per cent as compared to Spain and Iran having global market share of 45 per cent and 15 per cent, respectively, competing India in international market. UAE, Oman, Saudi Arabia, the Netherlands, Qatar, Iran, Kuwait as well as to nearby countries like Nepal and Bangladesh are the major importers of pomegranate.
The fruit is valued for its high remunerative returns under a wide range of climatically challenging cultivation conditions. Pomegranate can be grown with less water, tolerates high-temperature variations and responds to high-tech horticultural practices. Excellent flavour, nutritive value and medicinal properties of pomegranate fruit indicate its good potentiality for processing into value-added products having extended shelf life. It can be processed into variety of products besides having fairly good export potential. Lack of technological developments for commercialization, resource personnel and scientific research database are the major reasons for the underdevelopment of pomegranate processing industry in India, in spite of the known nutraceutical benefits and great global demand for potentially pomegranate-derived products resulting in very high post-harvest losses (20–40 per cent). Improper post-harvest management adds to another 10–15 per cent fresh produce losing its market value and consumer acceptability. Minimizing these losses can increase pomegranate supply without bringing additional land under cultivation. In order to exploit and popularize the medicinal and nutritive values of the pomegranate to its fullest extent, it becomes essential to explore the different ways of minimal processing and post-harvest technology applications.
Pomegranate is a very promising and emerging crop for its refreshing arils, juice and other products. It is well documented for its chemopreventive properties having medicinal value [4]. The pomegranate has been regarded as a food medicine of great importance for therapeutic purposes like colic, colitis-diarrhoea, dysentery, leucorrhea, paralysis and headache [1, 5]. The wide applications in the traditional Asian medicines both in Ayurvedic and Unani systems are well known. The therapeutic properties are reported to be due to the presence of betulinic and ursolic acids and different alkaloids such as pseudopelletierine, pelletierine and some other basic compounds [6]. There has been a remarkable increase in the commercial farming of the pomegranates globally due to the potential health benefits such as its high antioxidant, antimutagenic, and antihypertensive activities, and the ability to reduce liver injury [7, 8, 9, 10]. The pomegranate anthocyanins and polyphenolic compounds are known for scavenging activities and are able to elevate the antioxidant capacity of the human body. Pomegranate fruit is also known for its anti-inflammatory and anti-atherosclerotic activities against osteoarthritis, prostate cancer, heart disease and HIV-I [11, 12]. The juice from the pomegranates is one of the nature’s most powerful antioxidants. Pomegranate juice also increases the body’s resistance against infections, acts as cooling beverage and improves the function of kidney, liver and heart. All the parts of the tree, the roots, the reddish brown bark, leaves, flowers, rinds and seeds are reported to have rich source of different chemical constituents (Table 1) and thus included in medicines since thousand years. The sweet varieties of pomegranate are considered a good laxative, while those which are intermediate between sweet and sour are regarded as valuable in stomach inflammations and heart pain. The pomegranates have recently been found to boost activity of an enzyme which protects the cardiovascular risks.
Botanically, pomegranate is a fleshy berry, a balausta, and is considered to be a non-climacteric fruit. It has multiple ovule chambers separated by membranous walls (septum) and a fleshy mesocarp. The chambers are filled with shiny red seeds encased in succulent and edible red pink pulp called arils. However, the edible portion of pomegranate is testa [14]. The arils develop from the outer epidermal cells of the seed and elongate to a very large extent in a radial direction [15]. The colour of arils varies from white to deep red depending on the variety. The fruits are irregular round in shape and vary from yellow, green or pink to bright deep red in colour depending on the variety and stage of ripening [16]. Pomegranate has received special attention in recent years due to its properties, viz. rich in sugars, organic acids, minerals, anthocyanins, flavonoids, punicic acid, the sex steroid estrone and the phytoestrogen coumestrol.
The arils, edible portion of pomegranate, consist of around 80 per cent juice and 20 per cent seed [17]. The quality of the pomegranate fruit largely depends on its size, skin colour the absence of visual defects, such as sunburn, cracks, cuts, bruises and decay, and also on the presence of small and soft seeds as well as on aril colour, sugar and acid content [18]. The edible portion of pomegranate is an excellent dietary source as it contains a significant proportion of organic acids, soluble solids, polysaccharides, vitamins, fatty acids and mineral elements of nutritional significance (Tables 2 and 3) [20, 21]. It has a wide range of significance in human health, nutritional and livelihood security, which has been recognized resulting in increased fruit consumption [22].
Constituents
Edible fruits
Fresh fruits
Dry weight basis
Moisture (%)
78
19
Protein (%)
1.6
7.27
Total sugars (%)
14.6
66.36
Ascorbic acid (mg/100 g)
16.0
72.73
Ash (%)
0.7
3.18
Acidity (%)
0.58
2.64
Mineral (mg/100 g)
Calcium
10
45
Phosphorous
70
318
Magnesium
44
200
Potassium
133
604
Sodium
0.90
4.09
Iron
1.79
8.14
Zinc
0.82
3.73
Manganese
0.77
3.50
Copper
0.34
1.55
Table 2.
Chemical and mineral composition of pomegranate fruits.
Source: USDA National Nutrient Database for Standard Reference, Release 17 (2004).
However, poor post-harvest handling, storage recommendations, short shelf life and quality deterioration during transport, storage and marketing resulted in the limited consumption despite the increasing consumer awareness of the health benefits of pomegranate, whereas the occurrence of physiological disorders, viz. husk scald, splitting and chilling injury, reduces marketability and consumers acceptance.
For getting the quality pomegranate fruits, they are harvested at proper stage of maturity. Under Indian conditions in Maharashtra, the maturity of pomegranate fruit is judged by the following indices:
The fruit requires 130–150 days after fruit set for proper maturity.
In summer, the fruit colour changes from yellowish to dark red at maturity.
The fruit is harvested when it gives cracking sound when tapped.
The calyx at the distal end of the fruit gets closed at the time of maturity.
Properly matured fruit is easily scratched with fingernails.
The overripe fruit affects the shelf life and also the cost. The mature fruit is harvested carefully with minimum damage. The picking of fruit with stalk about 1 cm intact helps to increase its storage life. Detachment of the fruit with sharp knife is also recommended. The picking of the fruit is done early in the morning or late evening. After picking, the fruits are collected in the plastic crates and cleaned with the help of clothes in order to remove the dust with minimum damage.
Proper grading of the fruits is an important practice to maintain the quality and to fetch the optimum price in domestic as well as in international markets. The pomegranate fruits are graded on the basis of weight, size and external colour. During grading, the malformed, diseased, immature and cracked fruits are grouped into the following grades:
Supersize: The fruits of this grade have good attractive bright red colour with weight more than 750 g per fruit and do not have any spots on the skin.
King size: The fruits free from spots having an attractive red colour with weight ranging between 500 and 750 g come under this grade.
Queen size: The fruits free from spots having a bright red colour with weight ranging between 400 and 500 g come under this grade.
Prince size: The fully ripe fruits weighing between 300 and 400 g with red colour come under this grade.
Besides these grades, the fruits are also graded into two more grades such as 12-A grade and 12-B grade. The fruits weighing between 250 and 300 g with some spots on the skin are graded as 12-A grade. The fruits of this grade are generally preferred in South and North Indian markets.
In pomegranate, the size of packaging changes according to the grade of the fruits. Corrugated fibreboard boxes (CFBs) are used for packaging as they have many advantages such as lightweight, providing less or no damage to the fruits, easy to handle and reduction in the freight charges. In a single box, 4–5 fruits of Supersize, 6 fruits of King size, 9 fruits of Queen size and 12 fruits of Prince size and 12-A and 12-B grades are generally packed. The boxes with white colour having five plies are generally used for the export purpose, whereas the boxes with red colour with three plies are used for domestic markets. The red colour boxes are cheaper than the white coloured ones. The sizes of boxes used for packaging fruits of Supersize, Queen size and Prince size and 12-A and 12-B grades are 13 x 9 x 4 inches, 15 x 11 x 4 inches and 14 x 10 x 4 inches, respectively. During packing the fruits, the cut pieces of the waste paper are generally used as cushioning material. Then the graded fruits are placed on cushioning material followed by an attractive red colour paper on the boxes. Storage temperatures of 0–1.7°C and RH of 85–90 per cent are recommended for storing Kandahar pomegranates for 11 weeks [23].
It is reported that pomegranate cv. Banlaung were packed in plastic baskets and sealed with polyethylene (PE) bags (0.02 mm) and held at 5, 10 and 30°C (RT). The storage life of pomegranate in sealed PE bags at 10°C was extended up to 12 weeks with slight changes in quality [24]. The PLW of fruits cv. Jalore Seedless was up to 3.16 per cent during storage in refrigerated conditions when packed in perforated polyethylene bags [25]. The individual shrink wrapping of pomegranate cv. Ganesh held at 8°C showed the maximum shelf life of 70 days as compared to 20 days with wrapping and 15 days without wrapping at 25°C [26].
Pomegranate, physiologically being a non-climacteric fruit, does not ripen after harvest, and hence needs to be harvested when fully ripen on plant producing the optimal organoleptic characteristics [27, 28]. The storage life of pomegranate fruit at room temperature is merely around 10–15 days [29]. Temperature, relative humidity and atmosphere composition of gases are the environmental factors that decide the storage life of pomegranate and can be used effectively to increase the post-harvest life through the reduction in the respiration and the losses due to physiological and fungal decay [27].
However, the research efforts have helped to increase the production of pomegranate, minimize the post-harvest losses and enhance the shelf life for the purpose of obtaining maximum profit as well as the availability of fruits for longer season.
Careful post-harvest handling has been recognized as one of the important means to extend the post-harvest life of pomegranates as it reduces the majority of the mechanical damage (bruises, scrapes, cuts, compression, etc.) [27]. Modification and management of environmental conditions is another essential way to prolong the commercial life of pomegranates, and optimizing the environmental conditions to control the respiratory activity, transpiration and the development of microbial pathogens through forced air cooling to the temperature around 5°C reduces the physiological disorders and maintains the fruit quality specifications even for 2–3 months storage and extends the pomegranate commercial life [27].
The relative humidity is the second important factor and is closely related with storage temperature. To make the fruits healthy and clean, they must be gently brushed and stored with a relative humidity around 90–95 per cent to minimize the weight loss without increasing the microbial development and decay [27].
During the last few years, the activity in research and development on post-harvest management of pomegranate fruit has aimed at the application of new post-harvest storage technologies to extend the storage life of pomegranates, keeping the original quality of the freshly harvested fruits. It was targeted to the application of new refrigerated storage technologies (controlled atmospheres, modified atmosphere packaging with CO2 enrichment and/or reduction in O2), use of thermal treatments for fruit conditioning and curing, and intermittent warming during cold storage to avoid fungal development and the physiological disorders, physical treatments to keep the original quality of the fruit, avoiding fungal development, and the loss of quality characteristics (colour, flavour and texture) and nutritional properties (vitamins, antioxidants, health-promoting agents, etc.) having an effect on the fruit physiology and biochemistry and on the development of micro-organisms that contaminate the fruit surface [27].
8.1 Controlled and modified atmospheres
Studies in Israel had reported chilling injuries with symptoms, appearance of depression and browning of husk in post-harvest storage below 6°C. This damage caused by low temperatures can be inhibited by storing pomegranate fruits at temperatures between 2 and 6°C with 2–4 per cent O2 [30]. Further study was conducted to observe the effect of post-harvest storage at 5°C under controlled atmospheres on pomegranate quality and incidence of chilling injury recently [31]. Different controlled atmospheres were tested, and the quality of the fruits was compared to that of the fruits stored in air. Pomegranates of cultivar ‘Mollar’ were stored up to 8 weeks at 5°C and under 95 per cent relative humidity and were later transferred to 20°C for 6 days to simulate the commercialization period. It was further observed that storage under controlled atmospheres (10 per cent O2 and 5 per cent CO2; 5 per cent O2 and 5 per cent CO2; 5 per cent O2 and 0 per cent CO2) reduced weight loss, fungal decay and chilling injuries (husk surface scald). Though these treatments were found efficient to increase the quality or shelf life of pomegranate fruits, it however reduced the vitamin C and sugar contents in the fruit juice. In case of cultivar ‘Wonderful’, pomegranates were stored in air enriched with 10 or 20 per cent CO2, and it was observed that the colour of the seeds stored in air increased during refrigerated storage (10°C, 6 weeks), while the seed pigmentation was less intense in those of pomegranates stored in 10 per cent CO2 and even decreased in those fruits stored in 20 per cent CO2. This increased pigmentation in seeds was well correlated with the PAL activity of pomegranate seeds, a key enzyme of phenolic metabolism [32]. Nevertheless, these researchers found that storage under atmospheres with a moderate CO2 composition (10 per cent) prolonged the storage life of pomegranates and kept the original quality, including an adequate seed colour.
Study was also conducted for the use of plastic packaging for pomegranate fruits as well as pomegranate arils, in micro-perforated polypropylene bags. It was observed in these studies that the selective permeability of the polypropylene films for different gases in the bags are hermetically sealed, and for the respiration of pomegranate fruits, a modified atmosphere is generated around the fruit, which is enriched in CO2 and poor in O2. So it is important to use films that allow reaching the adequate gas levels, to produce the expected beneficial effects, without triggering the fermentative metabolism that will lead to off-flavours. Thus, it is possible to prolong the storage life of the fruits with an acceptable quality, showing the fruits an exceptional appearance during the commercialization period. This modified atmosphere packaging technique has also been used for the successful storage of minimally processed pomegranate seeds [8, 33], and a patent has been developed in the post-harvest and refrigeration laboratory of the CEBAS (CSIC) Institute [27].
8.2 Thermal treatments during cold storage
Though the pomegranate fruit is cultivated in tropics and subtropical areas, where this fruit has wide harvesting period, refrigeration is the only means to prolong the storage life of fruit up to 3 months; still, studies on the storage of pomegranates under refrigeration have received little attention.
In case of Spain, pomegranate harvest for the late cultivars starts in mid-September and end in the middle of November. To extend the commercialization, pomegranates are normally refrigerated for several weeks until Christmas. However, during their storage, fruits are affected by several physiological and enzymatic disorders and fungal attacks, deteriorating their quality. Spanish ‘sweet’ pomegranates suffer chilling injury if stored for more than 2 months at temperatures below 5°C, exhibiting symptoms, viz. browning of the rind, pitting, scald, an increased sensitivity to fungal development and decay, and internal discolouration and browning of the seeds [34]. Some cultivars, i.e. ‘Wonderful’, can be stored without problems for 2 months at 5°C, and the minimal safe temperature to store sweet pomegranates is 10°C [35]. This temperature, however, does not prevent fungal development. Previous studies have demonstrated that though the conventional storage of ‘Mollar’ pomegranate at 5°C and 90–96 per cent RH up to 8 weeks leads to acceptable decrease in fungal decay losses, the risk of chilling injury was not completely prevented. Storage under controlled atmospheres (5 per cent CO2 and 5 per cent O2) at 5°C and above 95 per cent relative humidity for 2 months improved the quality attributes of the freshly harvested pomegranate, although a moderate husk scald was observed [31].
A technique of intermittent warming that has proved useful in the prevention of chilling injury symptoms in other products has been recently applied to pomegranates [36]. Under this treatment, ‘Mollar de Elche’ pomegranates were stored at 0°C and 5°C and 95 per cent RH for 80 days with intermittent warming treatments at 20°C in cycles, for 1 day in every 6 days storage, followed by a commercialization period of 7 days at 15°C and 70 per cent RH. It was observed that while intermittent warming during the storage at 0°C prevented fungal development, increased susceptibility to chilling injury symptoms was there and storage at 5°C reduced considerably the chilling injury symptoms, but fungal attack was not completely inhibited. The warming treatments led to very good results in keeping the quality of pomegranates, especially when they were applied to pomegranates stored at 0°C.
Pre-conditioning at moderate temperature (30–40°C) and high RH (90–95 per cent) for a short period of time (1–4 days) is another technological treatment that has been utilized with success in pomegranate. This technique is also known as curing, that is applied before the conventional refrigerated storage. As reported, a pre-treatment at 35°C and 90–95 per cent RH applied for 3 days prior to a refrigerated storage for 80 days at 5 or 2°C and 90–95 per cent RH has reduced the pitting and husk superficial scald considerably (produced by the enzyme polyphenol oxidase) as compared to control pomegranates without the pre-conditioning treatment. The effects observed were more marked when the conservation was carried out at 2°C than at 5°C, particularly during the additional period of 1 week at 15–20°C and 70–75 per cent RH, applied to simulate the retail sale period [27, 36].
Pre-harvest treatment of ‘Mollar de Elche’ pomegranate with salicylates, especially salicylic acid @ 10 mM concentration, is found to be a safe, natural, and new tool to improve fruit quality parameters such as firmness, aril colour and individual sugar, especially fructose and organic acid contents at harvest. Moreover, aril content on bioactive compounds, such as phenolics, anthocyanins, and ascorbic acid, was also increased by salicylate treatments at harvest and during prolonged cold storage at 10°0C and 85–90 per cent of relative humidity also recording the reduction in weight loss. The quality traits and the concentration of bioactive compounds in fruits were found to be maintained at higher levels during the cold storage [18].
A sharp increase in PLW of fruits stored at room temperature is observed, whereas the increase in PLW is very slow in fruits stored in cool storage. The juice content of pomegranate fruit decreased significantly with the increase in storage period irrespective of post-harvest treatments and storage conditions, but the rate of decrease was faster at RT than in cool storage. Treatment of coating the fruits with wax coupled with 0.1 per cent of carbendazim recorded very low PLW as compared to other treatments under both the storage conditions. This might be due to the fact that wax acted as a barrier for the loss of moisture from the fruit surface and found to be more effective in high RH and low-temperature prevailing in cool storage. The fruits treated with wax showed low reduction in juice content as compared to control. Wax coating and fungicides when applied to fruit showed the moisture loss and respiration by forming a film around the fruit thereby retaining juice percentage. The shelf life of the fruits could be extended up to 30 days under RT and up to 65 days under control storage when treated with wax (9 per cent) coupled with 0.1 per cent carbendazim. The fruits stored in cold storage were more fresh, firm and glossy in appearance and attractive as compared to those stored at room temperature. The organoleptic rating of the fruits in terms of colour, flavour and texture was maximum in the fruits treated with wax coupled with 0.1 per cent carbendazim [29].
Pomegranate indicates the great scope for the processing into value-added products having extended shelf life (Figure 1). Well-matured big size fruits with attractive colour are readily picked by consumers, whereas low-grade pomegranates with fruit disorders, such as sunburnt husks, splits and cracks, reduce marketability and consumer acceptance. The new sector of pomegranate processing allows the use of such low-quality fruits that cannot be commercialized for the preparation of the new products. Though there is a great potential for pomegranate-derived products, the industrial processing as well as consumption of pomegranate is scarce due to peeling difficulties and lack of technologies for industrial processing of pomegranate [33, 38].
Figure 1.
Utilization of pomegranate for industrial processing: a flow chart (source: Yadav et al. [37]).
Considered as a whole, pomegranate contains 48 to 52 per cent of edible part, which comprises 78 to 80 per cent juice and 22 to 20 per cent seed. Juice is extracted by crushing seeds along with arils and marketed as a fresh juice as it has excellent flavour, attractive fragrance, delicious taste and high nutritive and medicinal value. Juice extraction is one of the important methods of value addition, and this juice can be processed further to prepare squash, syrup, nectar, jelly, concentrate and such other products (Figure 2). Also, pomegranate juice is used as an ingredient providing colour to the other products.
Figure 2.
Flow diagram of pomegranate juice processing technology: use of different clarification techniques (source: Alper et al. [39]).
Pomegranate contains punicalagins, hydrolysable tannins, anthocyanins and ellagic acid, and the compounds responsible for antioxidant capacity. Hence, pomegranate juice has higher contents of antioxidant compounds than the fresh fruit. While extracting the juice, relevant changes on the bioactive compounds are observed, in which punicalagins increase while ellagic acid and anthocyanins decrease. The flavour of pomegranate juice is characterized by esters, alcohols, and terpenes [40]. Terpenes are the predominant group in the pomegranate fresh juice aroma, while furans are only present in processed juices.
The phenolic constituents of pomegranate such as the anthocyanins give the colour, and other polyphenols such as flavonoids and some non-flavonoids are responsible for antioxidant properties, astringency and bitterness to juice [41]. The pomegranate juice is a rich source of polyphenols. The antioxidant qualities of pomegranate juice make it appealing for the production of health supplements and nutraceuticals [42].
10.1 Extraction of pomegranate juice
In case of the pomegranate, the foremost challenge in juice extraction is the peeling of the fruit as it is time-consuming and irritating as the hands get stained due to polyphenols and oxidative enzymes. To this date, commercial pomegranate juice production has only been mentioned by Cemeroglu [43], Vardin [44] and Saxena et al. [2].
For juice extraction, the fruits are prepared by rolling it on the hard surface to weaken the seed sacks within the fruit. MPKV, Rahuri, had developed a prototype machine which can separate arils and skin from fruits without causing damage to arils. CIPHET, Ludhiana, India had designed a hand tool for easy extraction of arils from fruits. Cut opening of the fruit, seed separation and pressing in screw press or basket press are the basic methods for the extraction of juice. In another method, the fruits are quartered and crushed or the whole fruits are pressed in hydraulic press and juice is strained out. Juice is extracted from the mature pomegranate seeds of sweet-type cultivars like Mollar and Bhagwa by pressing and liquefying. The pressing method gave the greater quantity as well as better quality. On whole fruit basis the juice yield is about 42 per cent, while on aril weight basis the yield is about 70 per cent [45]. Packaged press method for the extraction of pomegranate juice from separated arils, clarification of the pomegranate juice with gelatin at 4°C overnight and storing filtered juice at −30°C are described by Ozkan [46]. While, Saxena et al. [2] extracted 36.41 per cent of the juice by cutting the pomegranate fruits into quarters and pressing them in a rack and cloth hydraulic press under moderate pressure. The hydraulic extraction of juice should be at a pressure less than 100 psi to avoid undue yield of tannins from the rind. The phenolic constituents of the pomegranate juice are responsible for the colour, astringency, bitterness as well as the formation of cloudy appearance of fruit juices during concentration and storage as reported by de Simon et al. [47] and Spanos and Wrolstad [48]. Adsule and Patil [49] reported that average yield of juice was about 50 per cent on whole fruit basis, while from grains the yield was about 76 to 85 per cent by hand-press method. Chobe [50] separated grains and rind by pomegranate seed extractor and extracted 55 per cent pomegranate juice by crushing them in screw-type juice extractor. Vardin and Fenercioglu [51] obtained the 30 to 40 per cent pomegranate juice by pressing the whole pomegranate fruit in the manually operated packaged-type press in batches of 10 kg for 5 min. They also reported that the pomegranates can be pressed as a whole or as a divided or as granulated sac, but the best results were obtained by using whole fruits considering the time and cost, but the juicer with pressure of above 10 kg/cm2 resulted in the juice with excessive astringency and bitterness due to squeezing of phenolic compounds. Neifar et al. [52] extracted pomegranate juice with pH 4.1 and TSS 150 Brix by using the Philips centrifugal electric juicer (centrifugal method) and stored the juice at −20°C. Alpher et al. [39] described the process of extraction of pomegranate juice by pressing the two halved cut fruit into laboratory-type press which yielded 40–50 per cent juice. Marti et al. [53] described a process for the extraction of pomegranate juice having 3.8 pH in which aril pressurization followed by centrifugation at 6000 rpm for 10 min was used. Kumbhar et al. [54] reported that the average pomegranate juice extractions on whole fruit basis by hand-press method, mechanical method and screw-type juice extractor method were 71.6, 66.0 and 81.0 per cent, respectively. The pomegranate juice can also be extracted by squeezing the arils gently by hand-press method [55, 56]. However, Catania et al. [57], in industrial juice extraction with hydraulic press and a pneumatic press, recorded the better qualitative results in pneumatic press, whereas Catania et al. [58] reported that the application of different pressure values during pomegranate juice extraction process allowed the products of different quality.
10.2 Clarification of pomegranate juice
After the extraction, next important step in fruit juice processing is clarification or fining. Clarification helps to remove active haze precursors and thus decreases the potential for haze formation during storage. If the whole fruit is crushed or pressed with excessive pressure, a very large amount of excessively ‘puckery’ tannin, which is present in the rind of the pomegranate fruit, enters into juice and makes it undrinkable [44]. Nutritionists, however, recommend in contrast to preserve these compounds during the fruit juice processing because of their health protective effects. Pomegranate juice contains only trace amount of pectin that can be filtered easily after pressing without clarification. However, clarification is necessary to prevent the formation of cloudy appearance during storage and also to improve the taste of the product. Without clarification, the product has a bitter taste due to high tannin content. These polyphenols contribute to the haze formation through the mechanisms involving prior polymerization or condensation leading to the formation of the polymeric complexes and are collected at the bottom of the fruit juice bottle when stored. The main purpose of the clarification is to reduce the amount of the tannin and decrease the astringency of the product. Effective use of clarification agents requires optimization of their method of preparation as well as determination of the appropriate concentration needed to achieve clarification. For clarification, gelatin, bentonite, clays, etc., may be used as flocculating agent. Sahin et al. [59] observed the positive charge of gelatine at the pH of fruit juice which removed the negatively charged phenolic compounds by forming heavy flocculent precipitate forms. But if the gelatin is added above the level, turbidity increases [60]. Pectinase enzyme plays important role in clarification of the fruit juices by depectination [61]. The centrifugation method may also be employed for the clarification of the fruit juices. Vardin [44] reported the conventional heating treatment to raw pomegranate juice to inactivate naturally present enzymes and to destroy the vegetative micro-organisms. He further opined that heating or pasteurization of the pomegranate juice can be applied after clarification and filtration as heating before clarification increases the stability of haze formation which hinders the clarification of juice permanently. The natural clarification can be suitably employed for the clarification of pomegranate juice because the pomegranate juice was quite resistant to microbial spoilage at refrigeration temperature due to the presence of the polyphenolic compounds [43]. The most effective method to remove the phenolic compounds in pomegranate juice was the conventional fining with gelatin (300 mg/l) and bentonite (300 mg/l) along with polyvinylpolypyrrolidone (PVPP) [39] (Figure 2). Vardin and Fenercioglu [62] clarified the basket-pressed juice with gelatin, polyvinylpolypyrrolidone (PVPP) and natural sedimentation and reported that the phenolic substances were controlled in each clarification method. The most effective method of clarification was the application of 1 g/l gelatin before the heat treatment as it reduced the phenolic substances to an acceptable level, decreased turbidity, and preserved anthocyanins and colour density. In order to reduce the amount of tannin in pomegranate juice, Bayindirli et al. [63] found that the addition of 2 g/l gelatine is the most effective method of clarification which resulted in the clear and rich coloured juice as compared to the natural clarification which gave turbid juice. Removal of phenols can be accomplished with the help of filtration methods such as ultrafiltration. Neifar et al. [52] investigated that the laccase enzyme application to pomegranate juice resulted in the 40 per cent reduction of the total phenol but induced a threefold decrease of juice clarity. This drawback was overcome by the ultrafiltration of laccase-treated juice giving clear and stable pomegranate juice. Pectinases play a crucial role in clarification, extraction, reduction in viscosity, removal of peels and increment of the yield of fruit juices. The use of pectinase enzyme for the clarification of the fruit juices by depectination is reported by many authors [61, 64].
Ashima Kapoor and Hina Iqbal [65] used the tannase produced from fungal strain of Trichoderma harzianum for pomegranate juice clarification at 40°C and noted the tannin reduction of 57 per cent without the loss of its biochemical attributes such as pH, viscosity and sugar content and protein content.
10.3 Packaging of pomegranate juice
Selection of packaging material as well as processing influence the quality of foods, altering colour and nutrient composition during storage as a result of contact with oxygen and light transmission through them. Paperboard cartons with low-density polyethylene (LDPE) coating or glass containers are commonly used materials for juice packaging. Oxygen and light have destructive effects on the anthocyanin during storage. So, the packaging material also plays an important role in the colour stability of stored pomegranate product. Perez-Vicente et al. [66] assessed the influence of packaging material on colour and bioactive compounds of pasteurized pomegranate juice during storage at 24/18°C and 40–-50 per cent RH. They opined that the organoleptic quality of juice could be altered by packaging material, even if nutritional quality is not influenced suggesting that the oxygen permeability of the packaging material (which is the more damaging factor than light for pomegranate juice) should be minimized to avoid the detrimental effects on the retention of colour and some bioactive compounds. Glass containers were found to be better as compared to high-density polyethylene or polyvinylchloride containers with regard to retention of anthocyanins, vitamin C and organoleptic quality of the fruit juices [67]. Wasker and Deshmukh [68] studied the effect of light on the quality of stored pomegranate juice. The results showed that pomegranate juice packed in amber-coloured glass bottle retained better anthocyanins as compared to juice packed in colourless bottles.
Fathy [69] evaluated four different packaging materials for pomegranate juice during 8 weeks of storage at 4°C, the results of which approved that cartons consisting outside the polyethylene layer 13.5 per cent + cardboard 27 per cent + an inner layer of 59.5 per cent aluminium foil (Tetra Pak) as superior packages than cartons with an inner layer of ethylene vinyl alcohol copolymers and transparent PET bottles. It retained the high quality of pomegranate juice, preserving the high vitamin C content, intense red colour, fresh pomegranate flavour and absence of off-flavours. It also leads to the lower oxygen content in the headspace of the containers.
10.4 Storage of pomegranate juice
Pomegranate juice contains coloured pigments like anthocyanin, and the stability of these pigments is dependent on number of factors, viz. temperature, oxygen, light, pH and enzymatic action. Among these factors, storage temperature is considered as the important one. It has been reported by many researchers that pomegranate juice can be stored at ambient temperature as well as in cold storage at around 5 ± 1°C. But as compared to storage at ambient temperature, better retention of anthocyanins and reduction in enzymatic activity were reported in pomegranate juice stored in cold storage. As reported by Ahire [70], higher acceptable organoleptic score was observed in the hand-pressed or mechanical-pressed pomegranate juice packed in the glass bottles which was stored satisfactorily up to 3 months under cold storage (5 ± 1°C) conditions. Suryawanshi et al. [71] reported that the pomegranate juice can be stored up to 60 days at room temperature with the minimum changes in TSS, acidity, pH, total sugar, reducing sugars and tannin when pasteurized at 70°C and added 500 ppm sodium benzoate. Adam and Ongley [72] reviewed the beneficial influence of low-temperature storage on various pigmented fruit products, and they observed that bottling of fruits at low pH (between 1 and 2), without adding sugar, led to small but significant increase in the pigment stability. Pigment degradation was faster in juice stored at ambient (35°C) temperature. Shelar [73] and Sandhan [55] reported an increasing trend in TSS, pH, reducing sugars, non-reducing sugars and total sugars during 3 months storage of pomegranate juice-based carbonated beverage both at ambient and in cold temperature storage.
As it has been discussed earlier though the pomegranate fruit is rich in nutrients and antioxidants, the preparation of the arils is tedious, difficult and time-consuming procedure, and it makes the pomegranate fruit unpopular as a table fruit. It is for this reason the challenge of the development of ‘ready-to-eat’ pomegranate arils has been approached by several research groups in Spain and the USA as reported by Artes et al. [74]. In recent years, minimally processed ‘ready-to-eat’ pomegranate arils have become popular due to their convenience, high value, unique sensory characteristics and health benefits (Figure 3). MAP of minimally processed pomegranate arils offers additional tool for optimal use and value addition and also for the utilization of the lower-grade fruits, with increasing global interest in nutritional value as well as post-harvest handling of pomegranate fruit as reported by James Caleb et al. [76]. Minimally processed arils easily deteriorate in texture, colour, overall quality and a reduction in shelf life; hence, maintaining the nutritional and microbial quality of pomegranate arils is a major challenge [8, 33]. Washing with the sanitizing agents to reduce the initial microbial load, pH modifications, use of antioxidants, modified atmosphere packaging and temperature control are certain components of minimal processing as reported by Sepulveda et al. [75] (Figure 3). Washing the arils with the chlorine solution, followed by a mixture of ascorbic and citric acids and storing the seeds at 1°C in polypropylene films for the arils of the cultivar ‘Mollar de Eche’, allowed the formation of a modified atmosphere appropriate for the conservation of these arils. The preparation of the arils under very clean conditions and at temperatures close to 0°C prolonged the life of this product and maintained its quality. Storage at the higher temperatures (4–8°C) produced the product with lower quality and a shorter commercial life [8]. Potential increase in the shelf life of pomegranate arils by ensuring the microbial safety and monitoring the storage temperature with TTI is offered by the novel technologies such as smart packaging. Use of natural or non-destructive products as preservatives such as honey and UV-C radiation should be done in combination with MAP [76]. Ayhan and Esturk [77] found that the though pomegranate arils packed with air, nitrogen and enriched oxygen kept acceptable quality attributes on 18th day, the marketability period was limited to the 15th day for the low oxygen atmosphere. The effect of harvest time, use of different UV-C radiation and passive MAP with polypropylene basket sealed with BOPP film storage on sensory, chemical and microbial quality as well as on the shelf life of minimally fresh processed pomegranate var. Mollar de Elche arils was studied by Lopez-Rubira et al. [38]. The rate of respiration of fresh processed arils was higher in the post-harvest than in the earlier harvested fruits. No significant differences were observed between the control and UV-C-treated arils, and there was no observable interaction between passive MAP and UV-C treatment, except that the CO2 accumulation within aril packages was higher in December harvest than those of October due to their respiration rate. They also reported that unclear results were obtained due to the effect of UV-C radiation on the microbial growth of pomegranate arils and the shelf life of commercially produced pomegranate arils can be increased up to 10 days with the use of 100 per cent nitrogen in pet packages. No significant change in the total anthocyanin content of arils was observed. They also reported that the microbial counts of minimally fresh processed arils increased the shelf life, with mesophilic counts of control arils processed in October slightly higher than those from December. A low count of micro-aerophilic lactic acid bacteria (LAB) after 10 days of aril storage without any trace of fermentative metabolism was also recorded.
Figure 3.
Flow diagram of minimal processing of pomegranate arils (source: Sepulveda, et al. [75]).
Nunes et al. [78] in their investigation regarding metabolic response of the minimally processed pomegranate arils cv. Hicanar to UV-C treatments and stored at 2°C and 6°C observed that the UV-C illumination had an effect on the increase of phenol content in pomegranate arils, but TSS and citric acid percentage remained unaffected. Similarly, Maghoumy et al. [79] recorded that the combination of UV-C and high oxygen (initial 90 kPa O2) active MAP treatments for cold storage at 5°C and 90 per cent relative humidity as a good option to improve and extend the shelf life of fresh-cut arils as it preserved the superoxide dismutase and catalase had lower values of peroxidase and polyphenol oxidase and maintained the concentration of antioxidant compounds up to 14 days.
Gil et al. [33] in their study on pomegranate variety Mollar reported that arils washed with chlorinated water (100 mg/kg) and antioxidants solution (5 g/l ascorbic acid and 5 g/l citric acid), packed in OPP film, using an initial atmosphere actively modified to 0 ml/l CO2 and 20 ml/l O2 and stored at 1°C, can be stored up to 7 days maintaining a good quality and appearance, without visible attack of moulds or off-flavour developments. Similarly, Sepulveda et al. [80] investigated that pomegranate arils cv. Espanola washed and immersed in antioxidant solution (sodium hypochlorite, 200 ppm, 5 per cent ascorbic acid and 5 per cent citric acid) for 1 minute and stored at 5 ± 0.5°C in three semipermeable (SP) packaging can be stored for 7 days with commercial marketable acceptance. The best ability to maintain the physical, chemical and microbiological characteristics of the minimally processed pomegranate arils was shown by BB4 bags, but the sensory characteristics decreased from 7 to 14 days storage. Palma et al. [81] during their studies on the chemical and organoleptic characteristics of minimally processed seeds of pomegranate cv. Primosole, packed in a 40-μm-thick polypropylene film, stored at 5°C for 10 days observed that a passive modified atmosphere was established within the package, with a progressive increase in CO2 and decrease in O2 level, with increased ethylene concentration at the end of the storage. No significant changes in chemical properties were recorded, but increase in titratable acidity was observed in packaged seeds.
Palma et al. [82] despite physiological disorders as a severe external chilling damage appearing during storage on the rind made most of the fruit not marketable stored for 30 or 60 days at 5°C and 90 per cent RH, the overall quality with titratable acidity, total soluble solids, total polyphenol and anthocyanin content, antioxidant activity, sugar content and juice colour of ready-to-eat arils of ‘Primosole’ pomegranate processed at harvest and after 30 or 60 days of storage of whole fruit did not change substantially at the end of each storage time over fresh whole fruit. Similarly, the behaviour of ready-to-eat arils packaged in polypropylene trays wrapped with a polypropylene film to generate a passive modified atmosphere and stored at 5°C and 90 per cent RH for 10 days did not show marked differences in chemical and physical parameters giving the opportunity to store pomegranates fruit intended to be processed as ready-to-eat arils for a longer time.
Hess-Pierce and Kader [83] concluded that arils of ‘Wonderful’ pomegranate can be stored without changes in the physical and chemical characteristics of the fruit up to 16 days at 5°C with 20 per cent gas composition of CO2. They also observed the susceptibility of the mechanically damaged arils to moulds after 12 days. Ayhan and Esturk [77] recorded the commercially acceptable shelf life of minimally processed pomegranate cv. Hicaznar arils treated in a solution of 1 per cent citric acid (w/v) and 100 μLL − 1 chlorinated water as 18 days under air, nitrogen (100 per cent) and enriched oxygen (70 per cent) atmospheres, while 15 days under the low oxygen (5 per cent) atmosphere with package type of PP tray with BOPP film at 5°C storage. They detected the slight or no significant changes in chemical, physical and sensory quality during refrigerated storage. However, Belay et al. [84] reported that at both 5°C and ambient storage, arils of ‘Wonderful’ pomegranates under super atmospheric O2 significantly maintained the lowest microbial counts, better colour and texture properties compared to other MA conditions and also promoted the production of highest composition and amount of volatile compounds essential for flavour profile and antimicrobial effects identified in pomegranate arils. In Belay et al. [85] reported that bi-axial-oriented polypropylene-based film (PropaFilm) as a packaging film (66 per cent) fitted with 100 per cent cellulose-based film (NatureFlex) window was the best to maintain the quality of pomegranate arils for 9 days at 10°C temperature and 91 ± 2 per cent RH storage conditions and regulating the in-package relative humidity.
The effects of CO2 and O2 on the respiration rate of pomegranate arils cv. Hicaz evaluated the suitability of the common packaging material for designing the MAP was studied by Ersan et al. [86]. Respiration rate of the arils was significantly affected by O2 and CO2 concentrations in the surrounding atmosphere. Though lower respiration rate was achieved in 2 per cent O2 with 10 or 20 per cent CO2, MAP design analysis indicated that these target levels of O2 and CO2 cannot be achieved by LDPE and PP materials for commercial packages. The storage atmosphere enriched in CO2 (10, 15 and 20 per cent) helped to prolong the commercial life of pomegranate seeds up to 8 days at 10°C and 12 days at 5°C [27].
Adiletta et al. [87] reported semipermeable (SP) packaging system as a valid tool to preserve the qualitative and nutraceutical values in ready-to-eat pomegranate arils of cv. ‘Purple Queen’ over micro-perforated (MPP) system during cold storage at 5°C for 16 days and suggested that SP packaging system for ready-to-eat arils could be used in food industry applications as a convenient alternative to fresh fruit consumption. The SP packaging system found to reduce oxidative stress that increases antioxidant enzyme activities such as superoxide dismutase, catalase, and ascorbate peroxidase involved in the first line-of-defence against reactive oxygen species, detoxification, and the inhibition of PPO and GPX activity that are involved in aril-browning processes. SP packaging prevented the microbial growth and allowed the storage up to 16 days without exceeding the maximum-acceptable microbial limit than the MPP.
Honey has been used since ancient times as a sweetening agent in food and is the only concentrated form of sugar available worldwide. The use of honey treatments has been explored in preserving the fresh-like quality of arils and other cut fruits and to extend their shelf life. Efficacy of varying concentration of 10 and 20 per cent honey dip treatment on the quality and shelf life of minimally processed pomegranate arils cv. Hicaznar stored at 4°C in loosely closed containers was evaluated by Ergun and Ergun [88]. It was reported that honey solution (10 and 20 per cent) dipping 5 min can help in storage of arils at 4°C for 10 days with brilliant aroma than those treated with water. This treatment also helped in lowering the softening of the arils. The total aerobic count was lower in honey-treated arils, and the counts increased across all the treatments compared with the count immediately after the treatment. It also extended the quality of arils by delaying quality loss, microbial development and pigment changes, thus providing the safe organic method.
Martínez-Romero et al. [89] washed fresh pomegranate arils of cv. Mollar de Elche in a solution containing 100 μLL−1chlorine (NaOCl) for 5 min, followed by further rinsing in tap water and removal of excess water. It was followed by post-harvest treatments prior to storage in rigid polypropylene boxes for 12 days at 3°C. Among them, the combination of Aloe vera gel at 100 per cent + ascorbic acid and citric acid at 1 per cent retained the quality parameters of minimally processed arils such as firmness, colour and bioactive compounds along with reduction in microbial spoilage (significantly lower counts for both mesophilic aerobics and yeast and moulds) and increased the levels of total anthocyanins and total phenolics. Sensory analysis scores for flavour, texture, aroma, colour and purchase decision were higher in arils under this treatment without any off-flavours in pomegranate arils perceived as a consequence of A. vera gel treatment.
Ashtari et al. [90] reported that the gamma irradiation at 1–5 kGy reduced the population of microbial agents including bacteria, fungi and yeasts, but at the cost of reduction in amount of polyphenols, ascorbic acid, anthocyanin and antioxidant capacity. An increase in the amount of oxidative hydrogen peroxide in pomegranate aril and quality reduction in aril at low dose of 1 kGy was not remarkable and it also prevented the browning of the arils through the control of PPO enzyme activity, hence application of gamma irradiation for increasing the pomegranate aril shelf life is recommended.
Ozdemir and Gokmen [91] recommended coating of the pomegranate arils with an aqueous mixture of 1 per cent chitosan and 1 per cent ascorbic acid (chitosan-ascorbic coating) that significantly prolonged the lag time of micro-organisms and extended the microbiological shelf life of arils up to 21 days during storage at 5°C owing to antimicrobial activity of chitosan along with high sensory scores (colour, taste and aroma) which were found quite acceptable even after 25 days of refrigerated storage. Visual quality pomegranate aril in this treatment was protected due to ascorbic acid in the binary coating mixture as it is very effective anti-browning agent. Hasheminejad and Khodaiyan [92] studied the effect of four different coating dispersions, viz. chitosan, clove essential oil, chitosan nanoparticles and clove essential oil-loaded chitosan nanoparticles (CEO-ChNPs) on shelf life, and the quality of minimally processed pomegranate arils during cold storage at 5°C. The CEO-ChNPs significantly extended aril shelf life for 54 days due to the controlled release of the preserved volatile oil from ChNPs and their own inhibitory effects which significantly maintained microbial quality, weight, total soluble solid, titratable acidity, pH, total phenol and total anthocyanin content, as well as antioxidant activity and sensory quality in pomegranate arils, while uncoated arils became unusable at day 18 due to the incidence of fungal decay.
A summary of different cultivars, MAP of pomegranate arils, the types of the packaging adopted and the modified atmosphere condition attained in the packages is reviewed inTable 4.
Summary of modified atmosphere packaging of pomegranate arils, different cultivars, types of packaging film, modified atmosphere composition with temperature and duration of storage under MAP.
The arils were packed in polyethylene bags with syrup of 150 Brix and then frozen in a chest freezer, after preparing the arils same as that of minimally processed arils. The syrup concentration is similar to that of the arils juice concentration. The juice content of aril enters the syrup during freezing. Similarly, freezing of the arils coated with the sugar was also reported by Maestre et al. [94]. Due to the effect of anthocyanins, the coated sugar turned red during freezing and storage. To avoid an excessive loss of turgidity, arils should be eaten frozen.
13. Appertised arils
Appertised arils are prepared by putting the arils in syrup of 150 Brix and packed into metal tin. To sterilize, the tins were sealed and heated for 10 min. Most of the tins had arils that were too soft and that tasted cooked after stabilization, and the tins which were prone to less severe heat treatment had adequate textured arils with good taste.
14. Arils in vinegar
The arils were preserved in vinegar with an acidity of 5 per cent and packed in jar, and the resultant product was the brown coloured pomegranate arils.
15. Pomegranate jam and preserves
Pomegranate juice is concentrated and mixture is heated on slow fire for long period, and the resultant product is known as Anar Rub, which has fairly good keeping quality. The finished product has a thick consistency and TSS content is about 70–75 per cent which can be stored for 1 year and is utilized as jam [95]. Maestre et al. [94] reported that during the processing treatment 25 per cent of the pigments are destroyed in the jams and preserves made from the frozen Mollar pomegranate juice by adding pectins, saccharose and citric acid. They continue to degrade during preservation depending on the temperature than on light. The best preservation temperature reported was 5°C.
16. Jellies
Adsule et al. [96] prepared good pomegranate jelly on a small scale from Ganesh cultivar of pomegranate. An attractive jelly can be prepared from pomegranate juice [45]. But while making jellies, approximately 50 per cent of the anthocyanins present in pomegranate juice were lost. Maestre et al. [94] investigated that the acidification of juice produced a noteworthy improvement in the colour of jelly, both initially and during storage. During storage, certain colour differences were observed, which indicates that the pH was not only the parameter responsible for this characteristic.
17. Anardana
Sour wild types of pomegranate are utilized to prepare ‘Anardana’. It is dried aril of pomegranate mainly used as an acidulent instead of tamarind or dried green mango (Amchur) in North India in Indian cuisines like curries, chutney and other culinary preparations. It has anti-inflammatory properties and is a good source of dietary fibres. It is also used in the preparation of digestive candies and used in the traditional system of Ayurvedic and Unani medicine for ulcerative colitis. The improved processing technique for anardana consists of pre-cleaning, mechanized extraction of arils, solar/sundrying and packaging. After treating with sodium benzoate (600 ppm) for 10 min, arils are dehydrated in a drier at 45°C for 48 hours to get 10–12 per cent moisture content. It has attractive brown colour and can be stored for a long time in glass jars [97].
18. Pomegranate molasses
Pomegranate molasses is traditional Middle Eastern ingredient made from cooked pomegranate juice. It is thick and syrupy in texture, provides tangy flavour and is dark in colour. The sweetness comes from the concentration of natural sugars of fruits [37]. To make molasses, pomegranate juice is heated in a pan for about 45 min, allowing it to thicken but not overcooked. The product can be stored in air-tight container under refrigerated conditions for 3 months and typically used to flavour chutneys, curries and salad dressings to glaze or tenderize meat products.
19. Pomegranate concentrate
Pomegranate concentrate is prepared from natural pomegranate juice and is generally free from added sugar or preservatives. The commercially available juice concentrate generally contains 65–70 per cent TSS and has pH of 2.7 to 3.1. Majority of manufacturers in international market promote pomegranate juice as a health drink advocating its medicinal and health benefits. Different processes for the preparation of pomegranate concentrate are described by Maskan [98], which include keeping 60.5 0 Brix by using microwave, rotary vacuum and atmospheric heating processes for 23, 108 and 190 min, respectively. Increase in the reducing sugars, glucose and fructose level to 46.46 per cent, 23.89 per cent, and 22.53 per cent, respectively, during the conventional method of pomegranate juice concentration process was recorded by Hulya Orak [99]. Also, the potassium and magnesium mineral contents of concentrate increased during concentration.
20. Pomegranate syrup/grenadine
Pomegranate syrup is used for flavouring in alcoholic drinks, soft drinks and confectionaries. It is sold commercially as grenadine. Grenadine is light pomegranate syrup prepared by mixing juice and sugar. A syrup has bright purplish red colour and delightful taste and flavour. It has about 600 Brix with an added acidity of 1.5 per cent with citric acid. Grenadine can be preserved by pasteurization or by the addition of sodium benzoate and stored in amber glass bottles at room or refrigerated storage to retain its quality parameters.
Thakur et al. [100] prepared the arils-in-syrup product from wild pomegranate with 10 combinations of arils, syrup and TSS of syrup of which product with 40 per cent arils and 60 per cent syrup of 750B was adjudged to be the best according to its sensory and some physico-chemical characteristics like colour, titratable acidity and ascorbic acid.
21. Pomegranate beverages
Pomegranate juice can be processed for RTS beverages, blend and squash. These products are with delicate flavour. Ready-to-serve beverages and beverage blends are with 15 per cent juice content, and squash is prepared with 40 per cent juice. Squash is served in ratio of 1:4 with water (one part of squash with four parts of water).
The refrigerated probiotic beverage was found more stable for microbial, physico-chemical and colour attributes during storage, whereas beverage kept at room temperature could be microbiologically safe for 1 week [101].
The low alcohol beverage could be prepared from the fermentation of pomegranate juice as single substrate (100 per cent) or mixed with orange juice (1:1) using kefir grains which was proposed for a low-alcohol beverage production with high nutritional value deriving from both the substrates and the culture used and were also having the beneficial effects of pomegranate and orange juices, mainly due to their antioxidant properties, as well as the probiotic properties of kefir grains and bioactive ingredients found in kefir grains. Pomegranate: orange juice (1:1) improved the ability of kefir grains to ferment pomegranate juice and increased the survival rates of lactic acid bacteria (LAB) contained in kefir grains during storage. Specifically, 75 per cent cells remained viable after 4 weeks of storage in the fermented mixed substrate over 24 per cent in plain pomegranate juice, i.e. levels near to the limits set for products claiming probiotic properties [102].
The three commercial yeasts (for wine, beer and cider) were evaluated for the production of pomegranate alcoholic beverage (PAB) from a juice of ‘Wonderful’ variety at temperatures of 15 and 25°C [103]. PABs produced with these strains contained ethanol in the ranges of 5.6–7.0 per cent v/v, along with glycerol (2.65–6.05 g L−1), and low volatile acidity with decrease in total flavonoid, phenolic, and monomeric anthocyanin content and free radical-scavenging activity retaining 81–91 per cent of free radical-scavenging activity, 29–41 per cent of phenolics, 24–55 per cent of flavonoids, and 66–75 per cent of anthocyanins. The 30 different volatile compounds specifically 15 esters, 4 organic acids, 8 alcohols and 3 terpenes were also reported in PABs.
A functional pomegranate beverage using Lactobacillus paracasei K5 (a potential probiotic) immobilized on delignified wheat bran was also prepared [104]. The fermentations were carried out for 24 h at pH values of 3.3, 3.6 and 3.9 followed by storage for 4 weeks at 4°C. In all pH levels, the immobilized biocatalyst was found efficient for pomegranate juice fermentation maintaining ethanol production at low levels (0.5–1 per cent v/v). It indicated the potential of L. paracasei K5 to produce good quality and synbiotic pomegranate beverages.
22. Confectionery
Pomegranate juice is processed by adding sugar and heating it to bring the thick consistency. Researchers have found that approx. 50 per cent of total anthocyanins present in the juice are lost during jelly preparation and the acidification of juice improves the colour in the final product. Anar Rub (pomegranate jam) is prepared from juice by adding sugar and heating to a thick consistency. A jelly and hard candy is prepared from pomegranate [45].
A jelly product with 55 per cent mixed fruit juice content having cultivated and wild pomegranate juices in 80:20 ratio and 45 per cent sugar was prepared [105] and found to be safely stored for a period of 6 months under both the ambient and refrigerated conditions in pet jars as well as glass jars without much change in its various chemical attributes, viz. TSS, titratable acidity, ascorbic acid, anthocyanins, pectin, total phenolics and sensory quality characteristics, viz. colour, texture, flavour and overall acceptability. The jelly formulation containing 20 per cent gelatin, pure ‘Mollar de Elche’ pomegranate juice, 1 per cent citric acid and sucrose as sweetener [106] produced the best quality of jellies in terms of colour (highly reddish and bright red), texture, antioxidant capacity and sensory attributes. Devhare et al. [107] formulated the 20 per cent pomegranate juice-based chikki that retained its quality attributes for 3 months in LDPE bags. Micro-encapsulated pomegranate peel extract (MEPPE) was used by Palabiyik et al. [108] in the chewing gums successfully indicating their utility as a carrier for bioactive compounds. Similarly, many scientists utilized the seed as well as the peel extracts and oils in different confectionaries. Lashkari et al. [109] prepared the whey-less fruit feta cheese containing 20 per cent pomegranate juice which had the better antioxidant properties and oxidative stability, but its texture was weaker than control.
23. Wine
The pasteurized pomegranate juice is fermented with starter wine yeast. The juice is added with sugar to adjust Brix to 22–230. The fermentation is allowed to continue until desired level of alcohol is obtained. Pomegranate wine contains 9–10.1 per cent of alcohol and has pH 4.0, when incubated not more than 7 days. Clarification of wine is done by bentonite treatment or by centrifugation and is aged in the same manner as red grape wine.
24. Pomegranate powder
Pomegranate arils are dried and milled to prepare low-moisture pomegranate powder. Ellagic acid is the active ingredient in pomegranate powder. The freeze-dried pomegranate powder rich in ellagic acid have many applications and may be encapsulated for regular doses [110]. Husain et al. [111] have proposed grade standards to bring the commodity under the purview of AGMARK certification. The powder is utilized in the preparation of yanggaeng, breads, jelly and other products.
25. Pomegranate seed oil
Pomegranate seed, the by-product of pomegranate juice processing, contains considerable amounts of lipid, protein, sugars and essential minerals [112, 113], higher amount of mineral elements except potassium in seed than juice ([113, 114], a range of nutraceutical components, viz. sterols, γ-tocopherol, punicic acid, hydroxyl benzoic acids [115, 116], and phenyl aliphatic glycosides as phenethyl rutinoside [116, 117]). The extracts of pomegranate seed were reported with anti-diarrhoeal and antioxidant bioactivities [116, 118]. Pomegranate seed oil is extracted by pressing pomegranate seeds. The pomegranate seeds after extracting juice contain 12–20 per cent of pomegranate seed oil. The pomegranate seed oil is rich source of conjugated octadecatrienoic fatty acids such as punicic acid. The other fatty acids include catalytic acid and alpha-eleostearic acid. Pomegranate seeds oil also had a high content of ω-3, ω-6 and ω-9 essential fatty acids in adequate quantities, which have an essential role in human nutrition, prevention of the cardiac diseases, and protection of the human body from different cancers (anticancer) and in dissolving the saturated fatty acids in the body [116]. Pomegranate seed oil can also decrease the leukotriene production from arachidonic acid that has an important role in the accuracy of asthma in children, skin inflammation and paltelet aggregation association with cardiovascular diseases [116, 119, 120]. The antioxidant capacity of pomegranate oil is less than the pomegranate peel and higher than the pomegranate juice. The pomegranate seed oil is prepared by cold-pressing the pomegranate seeds. The total crude oil content obtained from seed ranges from 13 to 15 per cent on dry matter basis. The polyunsaturated fatty acid content in the oil was reported to 87.82 per cent [121]. The encapsulation of pomegranate seed oil using lipid-based carrier system is reported to protect the sensitive compounds from degradation. It also maintains the nutritional as well as functional aspects of the pomegranate seed oil. Pomegranate seed oil commercialization is also done by nanoemulsion.
26. Pomegranate seed powder
The pomegranate peel as well as seed powder have much higher exceptionally content of lysine, isoleucine and amino acids containing sulphur (methionine and cysteine), which are usually deficient in most food stuffs, than the reference protein pattern of FAO/WHO. Seed pulp extract can be used like a natural dye in alcoholic beverages as well as to impart taste and smell [122].
Hashemi et al. [123] assessed the effects of complementary treatment with pomegranate seed powder (PSP) oral supplementation @ 5 g twice daily on patients with type 2 diabetes mellitus, and after 8 weeks of treatment, they recorded that mean differences of fasting blood glucose, glycated haemoglobin (HbA1c), total cholesterol and triglyceride (TG) were significantly decreased in the PSP group over the placebo group treatment. In addition, post-intervention values of FBG and HbA1c were significantly lower in patients treated with PSP compared to the placebo group concluding that complementary treatment with PSP may have beneficial effects on FBG and HbA1c of patients with type 2 diabetes mellitus. However, its effect on TG and cholesterol was equivocal.
27. Pomegranate waste utilization
Pomegranate plant in a whole has medicinal, industrial and cosmetic values. All parts of the pomegranate tree, i.e. roots, bark, leaves, flowers, rind and seeds, can be processed for value-added products. Rind powder is having potential uses in medicines, in leather and dye industry and is used in the preparation of tooth powder. Through advance technology developed for the preparation of rind powder, it has been found that the recovery of rind powder is 15.5 per cent on whole fruit basis and 34 per cent on rind weight basis. The pomegranate bark powder also has effective medicinal uses and is used in many Ayurvedic preparations.
As a part of pomegranate industrialization, the field of pomegranate by-products is an interesting field to be exploited as it is a rich source of alkaloids, aromatic compounds and enzymes.
28. Pomegranate rind powder
Extracts of pomegranate rinds provided a major source of medieval ‘pomegranate’ ink in Europe [124, 125]. Extracts of the rind have also been used as dyes for textiles, and specialty craft inks are still created from pomegranate [125]. Pomegranate peel comprises around 20–50 per cent of total fruit weight which is rich in minerals especially potassium, calcium, phosphorus, magnesium and sodium; complex polysaccharides and high levels of different bioactive compounds, viz. phenolics, flavonoids, proanthocyanidin compounds and ellagitannins (ETs) such as punicalagins and its isomers. It also contains the punicalin, gallagic acid, ellagic acid and ellagic acid glycosides in smaller quantities. The peel extracts being free radical inhibitors and primary antioxidants that react with free radicals suggest their potential application as natural additives and functional ingredients after its incorporation in a real food model (Heena [126]). The predominant polyphenol fractions found in pomegranate peels powder are catechins, phenol gallic acid, caffeic acid, ellagic acid, p-coumaric acid and resorcinol compounds [116]. Higher phenol content and antioxidant activity as well as being a good source of crude fibre provide numerous health benefits such as ability to improve glucose tolerance and the insulin response, decrease serum LDL-cholesterol level, and reduced hyperlipidemia and hypertension. It also contributes to gastrointestinal health and the prevention of certain cancers such as colon cancer [127]. It is also known for its apparent wound healing properties [128]. The peels are rich in antioxidants and help in keeping bacteria and other infections away. It can be used in facepacks and skincare products. Peel powder restores the pH balance of the skin and hydrates the skin by locking the moisture thus keeping it smooth, soft and supple. It also helps to protect the skin from pollutants and other environmental toxins.
A detanninated peel powder with dual benefit, i.e. separated hydrolysable tannin/ellagitannin and good amount of nutritional components with appropriate amount of tannin, can be recommended as a novel cattle feed supplement [129]. Pomegranate peel powder meal (PPPM) supplementation in a-tocopherol supplemented (POSCON) diets to broiler Cobb 500 birds promoted feed conversion ratio and protein efficiency ratio. It improved average final body and other organ weights, spleen and gizzard weights, catalase enzyme activity, and nutrient digestibility, while it reduced the concentration of serum aspartate aminotransferase at concentrations of 4–8 g/kg feed [130]. Dried pomegranate peels can be used safely in sheep feeding at 1 per cent level to realize the best growth performance and depressed the price of ration cost and best relative economic efficiency [131].
Antibacterial and antioxidant characteristics of meat burgers incorporated with pomegranate rind powder extract (PRPE) were improved due to high concentration of total phenolic content that resulted in less oxidation of lipids and exhibited potentials as appropriate natural functional substitutes for synthetic antioxidants in the high-fat meat products (Maryam [132]) as well as natural and cheap antioxidant source for the enhancement of quality of raw ground pork meat [133] in the fresh-cut food sector such as fruit salads (Valentina [134]) as well as the development of value-added food products such as bread and cookies (Tandon [135]).
29. Conclusion
Pomegranate (P. granatum L.) is considered as a superfruit because of its high nutritive and therapeutic values. This fruit also has high antioxidant capacity and is rich in bioactive compounds. Though pomegranate is known as food medicine and has consumer appeal, the consumption of pomegranate is still scarce as it is considered as the most difficult fruit for peeling and extraction of arils, which is time-consuming, and also the phenolic metabolites in the fruit cause irritation and hand staining during extraction. Over the period, pomegranate processing and product diversification attained thereby have played a vital role in the increased consumption and utilization of pomegranate. The research and development activities on pomegranate fruit are aimed at developing technologies for new pomegranate-derived food products. Range of products can be developed through pomegranate processing, viz. minimally processed fresh arils, juice, squash, beverage, molasses, juice concentrates, frozen seeds, jam, jelly, marmalades, grenadine, wine, seeds in syrup, pomegranate wine, pomegranate powder, pomegranate rind powder, anardana, confectionery and pomegranate seed oil. Though there is large scope in pomegranate processing, the products derived had not yet popularized on large scale only because of lack of commercially viable processing technologies. Hence, there is the need for keen and immediate attention in meeting the research and developmental gaps for the commercialization and popularization of the pomegranate products as well as pomegranate processing technology. Industrial method of peeling, standardization of extraction and proper clarification methods of pomegranate juice, development of standards for packaging and storage of pomegranate-derived products, application of the new inline technologies such as MAP, ultrafiltration for pomegranate utilization and popularization of pomegranate-based products are the aspects that required to be emphasized in the research and technology development.
Hence, experimental studies should be carried out with more informative output on the metabolic properties of pomegranate and derived products under various conditions in order to develop the scientific database and to enable the successful application of the available technology for the commercialization and utilization of pomegranate processing technology and pomegranate products.
References
1.Schubert SY, Lansky EP, Neeman I. Antioxidant and eicosanoid enzyme inhibition properties of pomegranate seed oil and fermented juice flavonoids. Journal of Ethnopharmacology. 1999;66:11-17
2.Saxena AK, Manan JK, Berry SK. Pomegranate post harvest technology, chemistry and processing. Indian Food Packer. 1987;41(7/6):43-60
3.Anonymous. 2018. Indian Horticulture Database-2018. Pub. National Horticulture Board, Ministry of Agriculture, Govt. of India
4.Hertog MGL, Van Popel G, Verhoeven D. Potentially anticarcinogenic secondary metabolites from fruits and vegetables. In: Tomas-Barberan FA, Robins RJ, editors. Phytochemistry of fruits and vegetables. Oxford, UK: Claredon Press; 1997. pp. 313-329
5.Sadeghi N, Jannat B, Oveisi MR, Hajimahmoodi M, Photovat M. Antioxidant activity of Iranian pomegranate (Punica granatum L.) seed extracts. Journal of Agricultural Science and Technology. 2009;11:633-638
6.Singh RP, Gupta AK, Bhatia AK. Utilization of wild pomegranate in north west Himalayas-Status and Problems. In: Proceedings of National Seminar on Production and Marketing of Indigenous Fruits, New Delhi. 1990. pp. 100-107
7.Du CT, Wang PL, Francis FJ. Anthocyanins of pomegranate, Punica granatum. Journal of Food Science. 1975;40(2):417-418
8.Gil MI, Artes F, Tomas-Barberan FA. Minimal processing and modified atmosphere packaging effects on pigmentation of pomegranate seeds. Journal of Food Science. 1996;61:161-164
9.Lansky E, Hubert S, Neeman I. Pharmacological and therapeutical properties of pomegranates. In: Melgarejo P, Martinez JJ, editors. Proceedings of the First International Symposium on Pomegranate. Spain: CIHEAM; 1998. pp. 231-235
10.Tsuda T, Watanabe M, Ohshima K, Norinobu S, Choi S, Kawakishi S. Antioxidant activity of the anthocuanin pigments cyaniding 3-O-β-D glucoside and cyaniding. Journal of Agricultural and Food Chemistry. 1994;42:2407-2410
11.Malik A, Afaq F, Arfaraz S, Adhami VM, Syed DN, Mukhtar H. Pomegranate juice for chemoprevention and chemotherapy of prostate cancer. Proceedings of the National Academy of Sciences. 2005;102:14813-14818
12.Sumner MD, Elliott-Eller M, Weidner G, Daubenmier JJ, Chew MH, Marlin R. Effects of pomegranate juice consumption on myocardial perfusion in patients with coronary heart disease. The American Journal of Cardiology. 2005;96:810-814
13.Jurenka J. Therapeutic applications of Pomegranate: A review. Alternative Medicine Review. 2008;13(2):128-144
14.Pujari KH. Studies on hardness of seeds of pomegranate (Punica granatum L.). A M.Sc. (Agri.) thesis submitted to Mahatma Phule Agricultural University, Rahuri, Maharashtra, India. 1983. pp. 1-85
15.Fahan A. The seed. In: Plant anatomy. Jerusaleum: Hakkibutz hameuhad Publication; 1976. pp. 419-430
17.Cristofori V, Caruso D, Latini G, Dell’Agli M, Cammilli C, Rugini E. Fruit quality of pomegranate (Punica granatum L.) autochonous varieties. European Food Research and Technology. 2011;232:397-403. DOI: 10.1007/s00217-010-1390-8
18.García-Pastor ME, Zapata PJ, Castillo S, Martínez-Romero D, Guillén F, Valero D, et al. The effects of salicylic acid and its derivatives on increasing pomegranate fruit quality and bioactive compounds at harvest and during storage. Frontiers in Plant Science. 2020;11:668, p. 14. DOI: 10.3389/fpls.2020.00668
19.Chavan UD, Adsule RN, Kadam SS. Physico-chemical properties of pomegranate rind powder. Beverage and Food World. 1995;22(1):36
20.Ewaida EH. Nutrient composition of “Taifi” pomegranate (Punica granatum L.) fragments and their suitability for the production of jam. Arab Gulf Journal of Scientific Research. 1987;3:367-378
21.Fadavi A, Barzegar M, Aziz H. Determination of fatty acids and total lipid content in oilseed of 25 pomegranate varieties grown in Iran. Journal of Food Composition and Analysis. 2006;19(6):676-680
22.Prasad RN, Chandra R, da Silva JAT. Postharvest handling and processing of pomegranate. In: Chandra R, editor. Pomegranate, Fruit, Vegetable and Cereal Science and Biotechnology. Solapur, India: Global Science Books; 2010. pp. 88-95. (PDF) Characterization of Alternaria Species Associated with Heart Rot of Pomegranate Fruit. Available from: https://www.researchgate.net/publication/349679078_Characterization_of_Alternaria_Species_Associated_with_Heart_Rot_of_Pomegranate_Fruit [Accessed: July 6, 2022]
23.Pantastico B. Pineapple. In: Pantastico B, editor. Postharvest, Handling and Utilization of Tropical and Subtropical Fruits and Vegetables. Westport Connecticut: AVI; 1975. pp. 65-66
24.Pota S, Kesta S, Thongthaam MLC. Effect of packing materials and temperature on quality and storage of pomegranate fruits (Punica granatum L.). Kasestart Journal of Natural Sciences. 1987;21(4):328-333
25.Prasad RN, Bankar GJ, Vashishtha BB. Effect of packaging materials on the shelf life of pomegranate fruits cv. Jalore Seedless. Progressive Horticulture. 1995;26:133-135
26.Krishnamurthy S. Effect of shrink wrapping on shelf life of pomegranate. Poster Sessions Abstracts. International Food Conference-1993. 1993. pp. 150
27.Artes F, Tomas-Barberan FA. Postharvest technological treatments of pomegranate and preparation of derived products. In: Symposium on production, processing and marketing of pomegranate in the Mediterranean region: Advances in research and technology. (Eds.) Melgarejo P, Mertinez TJ, Zaragosa, Spain: CIHEAM-IAMZ. 2000:199-204
28.Artes F, Tudela JA, Villaescua R. Thermal postharvest treatment for improving pomegranate quality and shelf life. Postharvest Biology and Technology. 2000;18:245-251
29.Waskar DP. Studies on extension of postharvest life of pomegranate fruits ‘Bhagawa’. In: Sheikh MK et al., editors. Proc. IInd IS on Pomegranate and Minor, Including Mediterranean Fruits (ISPMMF - 2009). Acta Hort. 890. Vol. 2011. ISHS; 2009. pp. 455-459
30.Ben-Arie R, Or E. The development and control of husk scald on ‘Wonderful’ pomegranate fruit during storage. Journal of the American Society for Horticultural Science. 1986;111:395-399
31.Artés F, Marín JG, Martínez JA. Controlled atmosphere storage of pomegranates. Zeitschrift für Lebensmittel-Untersuchung und Forschung. 1996;203:33-37
32.Holcroft DM, Gil MI, Kader AA. Effect of carbon dioxide on anthocyanins, phenylalanine ammonia lyase and glucosyltransferase in the arils of stored pomegranates. Journal of the American Society for Horticultural Science. 1998;123:136-140
33.Gil MI, Martinez J, Artes F. Minimally processed pomegranate seeds. Lebensmittel-Wissenschaft und Technologie. 1996;29:708-713
34.Artes F. Factores de calidad y conservacion frigorifica de la Granada. In: II Jornadas Nacionales del Granado. Valencia: Univ. Politecnica de Valencia; 1992
35.Kader AA, Chordas A, Elyatem S. Response of Pomegranates to Ethylene Treatment and Storage Temperature. USA: California Agriculture: California Agricultural Experiment Station; 1984. pp. 14-15. ISSN: 0008-0845
36.Artes F, Marin JG, Martinez JA. Permeability rates of films for modified atmosphere packaging of respiring foods. In: Nicolai BM et al., editors. Food Quality. European Commission: Leuven; 1998. pp. 153-157
37.Yadav K, Sarkar BC, Kumar P. Pomegranate: Recent developments in Harvesting, Processing and Utilization. Indian Food Industry. 2006;25(2):55-62
38.Lopez-Rubira V, Conesa A, Allende A, Artes F. Shelf-life and overall quality of minimally processed pomegranate arils modified atmosphere packaged and treated with UV-C. Postharvest Biology and Technology. 2005;37:174-185
39.Alper N, Savas Bahceci K, Acar J. Influence of processing and pasteurization on colour values and total phenolic compounds of pomegranate juice. Journal of Food Processing and Preservation. 2005;29:357-368
40.Nuncio-Jáuregui N, Calín-Sánchez Á, Vázquez-Araujo L, Pérez-López AJ, FrutosFernández MJ, Carbonell-Barrachina ÁA. Processing pomegranates for juice and impact on bioactive components. In Processing and Impact on Active Components in Food. Chapter 76. London, UK: Elsevier; 2015. pp. 629-636
41.Gil MI, Tomas-Barberan FA, Hess-Pierce B, Holcroft DM, Kader AA. Antioxidant activity of pomegranate juice and its relationship with phenolic composition and processing. Journal of Agricultural and Food Chemistry. 2000;48(10):4581-4589
42.Singh RP, Murthy KNC, Jayaprakasha GK. Studies on the antioxidant activity of pomegranate (Punica granatum) peel and seed extracts using in vitro models. Journal of Agricultural and Food Chemistry. 2002;50(1):81-86
43.Cemeroglu B. Nar Suyu Oretim Teknolojisi Uzerine Bir Ara-stirma. Ziraat Fak, Yayinlari, Ankara. Publ. No.664: Ankara University Press; 1977. pp. 8-28
44.Vardin. The using possibilities of different pomegranate cultivars grown in Harran plain for using in food industry. Adana, Turkey: Ph. D. Thesis. Cukurova Univ; 2000
45.Phadnis NA. Pomegranate for dessert and juice. Indian Horticulture. 1974;19(3):9
46.Ozkan M. Degradation of anthocyanins in sour cherry and pomegranate juices by hydrogen peroxide in the presence of added ascorbic acid. Food Chemistry. 2002;78:499-504
47.de Simon BF, Perez-Ilzarbe J, Hernandez T, Gomez-Cordoves C, Estrella I. Importance of phenolic compounds for the characterization of fruit juices. Journal of Agricultural and Food Chemistry. 1992;38:1565-1571
48.Spanos GA, Wrolstad RE. Phenolics of apple, pear and white grape juices and their changes with processing and storage—A review. Journal of Agricultural and Food Chemistry. 1992;40:1478-1487
49.Adsule RN, Patil NB. Pomegranate: Hand Book of Fruit Science and Technology. New York: Marcel Dekker; 1995. pp. 455-464
50.Chobe RS. Studies on extraction, clarification, preservation and storage of pomegranate (Punica granatum L.) juice. M.Tech. (Agri) Thesis. Rahuri (Maharashtra), India: Mahatma Phule Krishi Vidyapeeth; 1999
51.Vardin H, Fenercioglu H. Study on the development of pomegranate juice processing technology: The pressing of pomegranate fruit. Proceedings of Ist International Symposium on Pomegranate. Ed. A. I. Ozguven. ISHS. Acta. Hort. 2009;818:373-381
52.Neifar M, Ellouze-Ghorbel R, Kamoun A, Baklouti S, Mokni A, Jaouani A, et al. Effective clarification of pomegranate juice using laccase treatment optimized by response surface methodology followed by ultrafiltration. Journal of Food Process Engineering. 2011;34:1199-1219. DOI: 10.1111/j.1745-4530.2009.00523.x
53.Marti N, Perez-Vicente A, Garcia-Viguera C. Influence of storage temperature and ascorbic acid addition on pomegranate juice. Journal of the Science of Food and Agriculture. 2001;82:217-221
54.Kumbhar SC, Kotecha PM, Kadam SS. Effect of method of juice extraction on quality of pomegranate wine. Beverage Food World. 2002;29(11):35-36
55.Sandhan VS. Preparation of carbonated beverage from pomegranate (Punica granatum L.) Fruits cv. Ganesh and Mridula. M.Sc. (Agri.) Thesis. Rahuri (M.S.), India: Mahatma Phule Krishi Vidyapeeth; 2003
56.Singh J, Singh AK, Singh HK. Preparation and preservation of pomegranate (Punica granatum L.) RTS. Beverage and Food World. 2005;32(12):45-46
57.Catania P, Alleria M, De Pasquale C, Vallone M. Effect of different processing methods on the quality of obtained pomegranate juice. In: Kalaitzis P et al., editors. Proc. III Int. Symp. on Horticulture in Europe – SHE2016. Vol. 1242. Acta Hortic; 2019. pp. 35-40. DOI: 10.17660/ActaHortic.2019.1242.5
58.Catania P, Comparetti A, De Pasquale C, Morello G, Vallone M. Effects of the extraction technology on pomegranate juice quality. Agronomy. 2020;10:1483, p. 14
59.Sahin S, Bayindirli L, Artik N. The effect of depectinization and clarification on sour cherry juice quality. Gida. 1992;17(1):35-42
60.Cemeroglu B. Meyve Suyu Uretim Teknolojisi. Ankara: Teknik Basim Sanayii; 1982
61.Vilquez F, Laetreto C, Cooke RD. A study of the production of clarified banana juice using pectinolytic enzymes. Journal of Food Technology. 1981;16:115-125
62.Vardin H, Fenercioglu H. Study on the development of pomegranate juice processing technology: Clarification of pomegranate juice. Nahrung/Food. 2003;47(5):300-303
63.Bayinderli L, Sahin S, Artik N. The effects of clarification methods on pomegranate juice quality. Fruit Processing. 1994;9:267-270
64.Song-nian G, Chil X, Quing D, Ying Z. Optimization of enzymatic clarification of pomegranate juice using response surface methodology. Storage and Process. 2011;2:1-3
65.Kapoor A, Iqbal H. Efficiency of tannase produced by Trichoderma Harzianum MTCC 10841 in pomegranate juice clarification and natural tannin degradation. International Journal of Biotechnology and Bioengineering Research. 2013;4(6):641-650
66.Perez-Vicente A, Serrano P, Abellan P, Garcia-Viguera C. Influence of packaging material on pomegranate juice colour and bioactive compounds, during storage. Journal of the Science of Food and Agriculture. 2004;84:639-644
67.Sethi V. Suitability of different packaging material for storing fruit juices and intermediate preserves. In: Souvenir of Symposium on Recent Development in Food Packaging. Mysore, India: CFTRI; 1985
68.Waskar DP, Deshmukh AN. Effect of packaging containers on the retention of anthocyanins of pomegranate juice. Indian Food Packer. 1995;49(1):5-8
69.Fathy AM. Quality and shelf life of pomegranate juice aseptically packed in different packaging materials. Middle East Journal of Applied Sciences. 2014;4(2):409-415
70.Ahire DB. Studies on extraction, packaging and storage of pomegranate (Punica granatum L.) juice cv. Mridula. M. Sc. (Agri.). Rahuri, (Maharashtra) India: Mahatma Phule Krishi Vidyapeeth; 2007
71.Suryawanshi AB, Kirad KS, Phad GN, Patil SB. Standardization of preservation method and their combination for safe storage of pomegranate juice at room temperature. The Asian Journal of Horticulture. 2008;3(2):395-399
72.Adam JB, Ongley MH. Changes in polyphenols of red fruits during heat processing. The degradation of anthocyanins in canned fruits. Tech. Bull. 23. Chipping Campden, Gloucestershire: The Campden Food Preservation Research Association; 1972
73.Shelar YV. Preparation of carbonated ready-to-serve (RTS) beverage from pomegranate (Punica gramaum L.) juice. M.Sc. (Agri.) Thesis. Rahuri (M.S.), India: Mahatma Phule Krishi Vidyapeeth; 2001
74.Artes F, Gil MI and Martinez JA. Procedimiento para la conservation de semillas de granada en fresco. Patent No. 9502662. 1995
75.Sepulveda E, Galletti L, Saenz C, Tapia M. Minimal processing of pomegranate var. Wonderful. In: Melgarejo P, Mertinez TJ, editors. Symposium on Production, Processing and Marketing of Pomegranate in the Mediterranean Region: Advances in Research and Technology. Zaragosa, Spain: CIHEAM-IAMZ; 2000. pp. 237-242
76.James Caleb O, Opara UL, Witthuhn CR. Modified atmosphere packaging of pomegranate fruit and arils: A review. Food Bioprocess Technology. 2011
77.Ayhan Z, Esturk O. Overall quality and shelf life of minimally processed and modified atmosphere packaged “Ready-to-Eat” pomegranate arils. Journal of Food Science. 2009;74:C399-C405
78.Nunes C, Graca A, Yildirim I, Sahin G, Erkan M. Metabolic response to UV-C treatment on minimally processed pomegranate arils. In: Erkan M, Aksoy U, editors. 6th International Postharvest Symposium. Vol. 877. ISHS. Acta Horticulure; 2010. pp. 657-662
79.Maghoumi M, Gómez P, Mostofi Y, Zamani Z, Artés-Hernández F, Artés F. Combined effect of heat treatment, UV-C and superatmospheric oxygen packing on phenolics and browning related enzymes of fresh-cut pomegranate arils. LWT—Food Science and Technology. 2014:54. DOI: 10.1016/j.lwt.2013.06.006
80.Sepulveda E, Saenz C, Berger H, Galletti L, Valladares C, Botti C. Minimal processing of pomegranate cv. Espanola: Effect of three package material. In: Ben-Arie R, Philosoph-Hadas S, editors. Proc. 4th Int. Conf. on Postharvest. Vol. 553. ISHS; 2001. pp. 711-712
81.Palma A, Schirra, D’Aquino S, La Malfa S, Continella G. Chemical properties changes in pomegranate seeds packaged in polypropylene trays. In: Ozguven AI, editor. Proc. Ist IS on Pomegranate. Vol. 818. ISHS; 2009. pp. 323-329
82.Palma A, Continellab A, La Malfab S, Gentileb A, D’Aquinoa S. Overall quality of ready-to-eat pomegranate arils processed from cold stored fruit. Post Harvest Biology and Technology. 2015;109:1-9
83.Hess-Pierce B, Kader A. Carbon dioxide enriched atmospheres extend postharvest life of pomegranate arils. In: Gorny JR, editor. Seventh International Controlled Atmosphere Research Conference. CA ‘97. Proceedings Vol.5; Fresh-Cut Fruits and Vegetables and MAP. Davis, CA: Dept. of Pomology, Univ. of California; 1997. p. 122
84.Belay ZA, Caleb OJ, Opara UL. Impacts of low and super-atmospheric oxygen concentrations on quality attributes, phytonutrient content and volatile compounds of minimally processed pomegranate arils (cv. Wonderful). Post Harvest Biology and Technology. 2017;124:119-127
85.Belay ZA, Caleb OJ, Mahajan PV, Opara UL. Design of active modified atmosphere and humidity packaging (MAHP) for ‘Wonderful’ pomegranate arils. Food and Bioprocess Technology. 2018:17. DOI: 10.1007/s11947-018-2119-0. Pub. Online: May 31, 2018
86.Ersan S, Gunes G, Zor AO. Respiration rate of pomegranate arils as affected by O2 and CO2 and design of modified atmosphere packaging. In: Erkan M, Akoy U, editors. Proc. 10th Intern. Controlled and Modified Atmosphere Research Conference. Vol. 876. ISHS; 2010. pp. 189-196
87.Adiletta G, Petriccione M, Liguori L, Zampella L, Mastrobuoni F, Di Matteo M. Overall quality and antioxidant enzymes of ready to eat ‘Purple Queen’ pomegranate arils during cold storage. Post Harvest Biology and Technology. 2019;155:20-28
88.Ergun M, Ergun N. Maintaining quality of minimally processed pomegranate arils by honey treatments. British Food Journal. 2009;111(4):396-406
89.Martinez-Romero D, Castillo S, Guillen F, Diaz-Mula HM, Zapata PJ, Valeroa D, et al. Aloe vera gel coating maintains quality and safety of ready-to-eatpomegranate arils. Postharvest Biology and Technology. 2013;86:107-112
90.Ashtari M, Khademi O, Soufbaf M, Afsharmanesh H, Sarcheshmeh MAA. Effect of gamma irradiation on antioxidants, microbiological properties and shelf life of pomegranate arils cv. ‘Malas Saveh’. Scientia Horticulturae. 2019;244:365-371
91.Özdemir KS, Gökmen V. Extending the shelf-life of pomegranate arils with chitosanascorbic acid coating. LWT-Food Science and Technology. 2017;76:172-180
92.Hasheminejad N, Khodaiyan F. The effect of clove essential oil loaded chitosan nanoparticles on the shelf life and quality of pomegranate arils. Food Chemistry. 2018. DOI: 10.1016/j.foodchem.2019.125520
93.Garcia E, Salazar DM, Melgarejo, Coret A. Determination of the respiration index and of the modified atmosphere inside the packaging of minimally processed products. In: Melgarejo P, Mertinez TJ, editors. Symposium on Production, Processing and Marketing of Pomegranate in the Mediterranean Region: Advances in Research and Technology. Zaragosa, Spain: CIHEAM-IAMZ; 2000. pp. 247-251
94.Maestre J, Melgarejo P, Tomas-Barberan FA, Garcia-Viguera C. New food products derived from pomegranate. In: Melgarejo P, Mertinez TJ, editors. Symposium on Production, Processing and Marketing of Pomegranate in the Mediterranean Region: Advances in Research and Technology. Zaragosa, Spain: CIHEAM-IAMZ; 2000. pp. 243-245
95.Siddappa GS, Bhatia BS. The identification of sugars in fruits by chromatography. Indian Journal of Horticulture. 1954;11:19
96.Adsule RN, Kotecha PM, Kadam SS. Preparation of wine from pomegranate. Beverage and Food World. 1992;19(4):13-14
97.Anonymous. Anardana. In Technology Options. FICCI Agribuisiness Information Centre. 2005. Available from: http://www.ficciagroindia.com/aic/technology-options/anardana.html
98.Maskan M. Production of pomegranate (Punica granatum L.) juice concentrate by various heating methods: Colour degradation and kinetics. Journal of Food Engineering. 2006;72(3):218-224
99.Hulya Orak H. Evaluation of antioxidant activity, colour and some nutritional characteristics of pomegranate (Punica granatum L.) juice and its sour concentrate processed by conventional evaporation. International Journal of Food Science Nutrition. 2009;60(1):1-11
100.Thakur NS, Dhaygude GS, Joshi VK. Development of wild pomegranate aril-in-syrup and its quality evaluation during storage. International Journal of Food and Fermentation Technology. 2013;3(1):33-40. DOI: 10.5958/j.2277-9396.3.1.003
101.Thakur M, Deshpande HW, Bhate MA. Investigation of microbial, physicochemical and color properties of probiotic pomegranate beverage during storage. International Journal of Current Microbiology and Applied Sciences. 2018;7:638-650
102.Kazakos S, Mantzourani I, Nouska N, Alexopoulos A, Bezirtzoglou E, Bekatorou A, et al. Production of low-alcohol fruit beverages through fermentation of pomegranate and orange juices with kefir grains. Current Research in Nutrition and Food Science. 2016;4(1):19-26
103.Kokkinomagoulos E, Nikolaou A, Kourkoutas Y, Kandylis P. Evaluation of yeast strains for pomegranate alcoholic beverage production: Effect on physicochemical characteristics, antioxidant activity, and aroma compounds. Microorganisms. 2020;8:1583, p. 17. DOI: 10.3390/microorganisms8101583
104.Mantzourani I, Terpou A, Bekatorou A, Mallouchos A, Alexopoulos A, Kimbaris A, et al. Functional pomegranate beverage production by fermentation with a novel synbiotic L. paracasei biocatalyst. Food Chemistry. 2019:36. DOI: 10.1016/j.foodchem.2019.125658
105.Thakur NS, Dhaygude GS, Sharma A. Development of cultivated and wild pomegranate mixed fruit jelly and its quality evaluation during storage. Journal of Applied and Natural Science. 2017;9(1):587-592
106.Cano-Lamadrid M, Calín-Sánchez A, Clemente-Villalba J, Hernández F, Carbonell-Barrachina ÁA, Sendra E, et al. Quality parameters and consumer acceptance of jelly candies based on pomegranate juice “Mollar de Elche”. Foods. 2020;9:516. DOI: 10.3390/foods9040516
107.Devhare PF, Kotecha PM, Godase SN, Chavan UD. Studies on utilization of pomegranate juice in the preparation of peanut chikki. International Journal of Chemical Studies. 2021;9(1):1532-1535
108.Palabiyik I, Toker OS, Konar N, Gunes R, Guleri T, Alasalvar H, et al. Phenolics release kinetics in sugared and sugar-free chewing gums: Microencapsulated pomegranate peel extract usage. International Journal of Food Science and Technology. 2018:1-7
109.Lashkari H, Varidi MJ, Eskandari MH, Varidi M. Effect of pomegranate juice on the manufacturing process and characterization of feta-type cheese during storage. Journal of Food Quality. 2020:11. Article ID 8816762. DOI: 10.1155/2020/8816762
111.Husain MI, Devikar GY, Singh G, Jaiswal PK. Quality evaluation of pomegranate seed and powder. Spice India. 2004;17(7):28-32
112.El-Nemr SE, Ismail IA, Ragab M. Chemical composition of juice and seed of pomegranate fruit. Die Nahrung. 1990;34:601-606
113.Dadashi S, Mousazadeh M, Emam-Djomeh Z, Mousavi SM. Pomegranate (Punica granatum L.) seed: A comparative study on biochemical composition and oil physicochemical characteristics. Biochemical composition of pomegranate seed oil. International Journal of Advanced Biological and Biomedical Research. 2013;1(4):351-363
114.El-Nemr S, Ismail I, Ragab M. The chemical composition of the juice and seeds of pomegranate fruits. Journal of Fruits Vegetables and Nuts. 1992;11:162-164
115.Liu G, Xu X, Hao Q , Gao Y. Supercritical CO2 extraction optimization of pomegranate (Punica granatum L.) seed oil using response surface methodology. LWT-Food Science and Technology. 2009;42:1491-1495
116.Rowayshed G, Salama A, Abul-Fadl M, Akila-Hamza S, Mohamed EA. Nutritional and chemical evaluation for pomegranate (punica granatum l.) fruit peel and seeds powders by products. Middle East Journal of Applied Sciences. 2013;3(4):169-179
117.Wang RF, Xie WD, Zhang Z, Xing DM, Ding Y, Wang W, et al. Bioactive compounds from the seeds of Punica granatum (Pomegranate). Journal of Natural Products. 2004;67:2096-2098
118.Singh RP, Murthy KNC, Jayaprakasha GK. Studies on the antioxidant activity of pomegranate (Punica granatum) peel and seed extracts using in vitro models. Journal of Agricultural and Food Chemistry. 2002;50:81-86
119.Adhami VM, Mukhtar H. Polyphenols from green tea and pomegranate for prevention of prostate cancer. Free Radical Research. 2006;40:1095-1104
120.Huxley RR, Neil H. The relationship between dietary flavonol intake and coronary heart disease mortality: A meta-analysis of prospective cohort studies. European Journal of Clinical Nutrition. 2003;57:904-908
121.Kola O, Erva P, Reis AM, Devrim OB, Emrah M, Burcak T. Fatty acids, sterols and triglycerides composition of cold pressed oil from pomegranate seeds. La Rivista Italiana Delle Sostanze Grasse Vol. XCVIII. pp: 197-204. _LuGLIO/SETTEMBRE 2021. 2021. Available from: https://www.innovhub-ssi.it/kdocs/2021187/2021_vol._983_-_art._04_-_kola.pdf
122.Pedriali CA, Fernandes AU, dos Santos PAD, da Silva MM, Severino D, da Silva MB. Ciênc. Tecnol. Aliment. Campinas. 2010;30(4):1017-1021
123.Hashemi MS, Namiranian N, Tavahen H, Dehghanpour A, Rad MH, Jam-Ashkezari S, et al. Efficacy of pomegranate seed powder on glucose and lipid metabolism in patients with Type 2 Diabetes: A prospective randomized double-blind placebo-controlled clinical trial. Complementary Medicine Research. 2020;28:226-233. DOI: 10.1159/000510986
124.Carvalho DN. Forty Centuries of Ink. 1999. Available from: https://www.gutenberg.org/cache/epub/1483/pg1483-images.html [Accessed: October 6, 2021]
125.Stover E, Mercure EW. The pomegranate: A new look at the fruit of paradise. HortScience. 2007;42(5):1088-1092
126.Jalal H, Pal MA, Hamdani H, Rovida M, Khan NN. Antioxidant activity of pomegranate peel and seed powder extracts. Journal of Pharmacognosy and Phytochemistry. 2018;7(5):992-997
127.Ranjitha J, Bhuvaneshwari G, Terdal D, Kavya K. Nutritional composition of fresh pomegranate peel powder. International Journal of Chemical Studies. 2018;6(4):692-696
128.Murthy KN, Reddy VK, Veigas JM, Murthy UD. Study on wound healing activity of Punica granatum peel. Journal of Medicinal Food. 2004;7(2):256-259. DOI: 10.1089/1096620041224111
129.Kushwaha SC, Bera MB, Kumar P. Nutritional composition of detanninated and fresh pomegranate peel powder. IOSR Journal Of Environmental Science, Toxicology And Food Technology. 2013;7(1):38-42
130.Akuru EA, Mpendulo CT, Oyeagu CE, Nantapo CWT. Pomegranate (Punica granatum L.) peel powder meal supplementation in broilers: Effect on growth performance, digestibility, carcase and organ weights, serum and some meat antioxidant enzyme biomarkers. Italian Journal of Animal Science. 2021;20(1):119-131. DOI: 10.1080/1828051X.2020.1870877
131.Omer HAA, Abdel-Magid SS, Awadalla IM. Nutritional and chemical evaluation of dried pomegranate (Punica granatum L.) peels and studying the impact of level of inclusion in ration formulation on productive performance of growing Ossimi lambs. Bulletin of the National Research Centre. 2019;43:182. DOI: 10.1186/s42269-019-0245-0
132.Shahamirian M, Eskandari MH, Niakousari M, Esteghlal S, Gahruie HH, Khaneghah KM. Incorporation of pomegranate rind powder extract and pomegranate juice into frozen burgers: Oxidative stability, sensorial and microbiological characteristics. Journal of Food Science and Technology. 2019;56(3):1174-1183. DOI: 10.1007/s13197-019-03580-5
133.Qin Y-Y, Zhang Z-H, Li L, Xiong W, Shi J-Y, Zhao T-R, et al. Antioxidant effect of pomegranate rind powder extract, pomegranate juice and pomegranate seed powder extract as antioxidants in raw ground pork meat. Food Science and Biotechnology. 2013;22(4):1063-1069. DOI: 10.1007/s10068-013-0184-8
134.Lacivita V, Incoronato AL, Conte A, Del Nobile MA. Pomegranate peel powder as a food preservative in fruit salad: A sustainable approach. Food. 2021;2021(10):1359. DOI: 10.3390/foods10061359
135.Palak T, Ranu P, Anisha V. Sensory Analysis of Pomegranate Peel Powder in the Development of Value Added Food Products. International Journal of Science and Research. 2020;9(11):414-417. DOI: 10.21275/SR201106190108
Written By
Sangram S. Dhumal, Ravindra D. Pawar and Sandip S. Patil
Submitted: 20 February 2022Reviewed: 02 May 2022Published: 26 August 2022
Open access peer-reviewed chapter
