Management and Processing of Palm Oil (Elaeis guineensis Jacq): The Crop for Future

Abstract

India is one of the largest producers and consumers of edible oils and fats in the world. It contributes to about 7–8% of the world’s oilseeds and 6–7% of the global vegetable oils and is the fifth largest edible oil economy in the world. Even though India occupies a prominent position in the global oilseed production, its average yield for major oilseeds is 40–60% below the world average and has been growing at a slow pace. India is having rich agroecological diversity and is ideally suited for growing all major oil seed crops. It is reported that India excessively import edible oil such as palm oil from Malaysia and Indonesia and soybean oil from Argentina because the average yield of many of these oil seed crops is very low, compared to other crops like palm oil. This stressful situation is further aggravated by some traders who indulge in malpractices of adulteration of these oils with cheaper oils and synthetic colors for economic benefit. This chapter discusses the state-of-the-art of crop management and processing of palm oil, which is considered as the future crop.

1. Introduction

Being the fifth largest edible oil economy in the world, India contributes to about 7–8% of the world’s oilseeds and about 6–7% of the global vegetable oils. Even after occupying a prominent position in the global oilseed production, India’s average yield for major oilseeds is 40–60 percent below the world average and has been growing at a slow pace. The majority of edible oil imports of India are palm oil from Malaysia and Indonesia and soybean oil from Argentina because the average yield of many of these oil seed crops (ground nut, mustard or rape seed, sunflower, sesame, safflower, and niger) is very low, compared with other crops like Palm oil. It is the highest edible oil-yielding crop giving up to 5–6 tonnes of oil per hectare per year among the vegetable oil-giving crops under the good agricultural management practices [1]. Palm oil is well received by consumers, especially as a means of cooking due to its value benefits and price advantage. It is a good raw material for the production of cosmetics, pharmaceuticals, nutraceuticals, etc. In general, it can be said that palm oil is a source of health and nutrition improvement, value addition, recycling of environmentally friendly waste, a source of diversification, import substitution, creation, and sustainability.

2. Health and nutrition of palm oil

Carbohydrates, proteins, fats & lipids, minerals, vitamins, and water are the major nutrients required by the human being. Carbohydrates, proteins, and fats will be breakdown into and utilized for different purposes. Fats or oil is an essential part of human nutrition, and performs several functions viz., forms structural components of biological membranes and acts as an energy source, and derivates serve as vitamins and hormones, protecting from environment, and act as insulation. Lipids or fats are available from different sources. In Western Europe, it is dairy and animal fats; in India, its groundnut and mustard oil; in South Asia, coconut oil; in West Africa, palm oil. Palm oil is also a major source of dietary fat in India, Latin America, South-East Asia, China, Pakistan, and West Africa for the reason that palm oil is the most economic source of edible fat.

3. Edible oil imports and domestic consumption in India

Evidences state that palm oil inhibits the formation and reduction in the growth of tumors. Most important minor components of palm oil at a concentration less than 1000 ppm are alpha-carotene and beta-carotene (precursors of vitamin-A) and tocopherols and tocotrienols (precursors of vitamin E). Palm oil and its fractions are used in the production of margarine. Compared with unsaturated oils, palm oil is suitable for deep frying because of its relative stability to high temperatures.

Red palm oil is produced from crude palm oil by a novel process involving the pretreatment of crude palm oil followed by deacidification and deodorization using molecular distillation which is a carotene-rich refined edible palm oil. Refined red palm oil meets the standards of refined edible oil specifications and retains up to 80% of carotene and vitamin E. Red palm oil is the richest source of carotenoids, which stops free radical-mediated reactions. Carotenoids are known for their health-promoting properties that act as a source of pro-vitamin A and anticancer agent, and prevent cardiovascular diseases.

Tocopherols and tocotrienols are simply called as vitamin E, the principal role of vitamin E in the body is it acts as an antioxidant that helps in maintaining cell membrane stability and is the most essential for neurological function. Tocopherols are commonly available in most vegetable oils and fats but tocotrienols are rarely present. The most encouraging part of palm oil is that it is the richest source of tocotrienols that plays a significant role in exhibiting anticancer properties and greater physiological efficiency in inhibiting the growth of human tumor cells than tocopherols.

4. Palm oil-growing states in India

4.1 Botany of palm oil

Palm oil (Elaeis guineensis Jacq.) belonging to the family Arecaceae is considered as a smallholder’s irrigated crop in India. It is a monoecious plant, belonging to Kingdom Plantae and Order Arecales. The term “Elaeis” was derived from the Greek word “Elalon” meaning oil, while “guineensis” is attached with its origin to Guinea Coast [2]. The other species of commercial importance identified under this genus are Elaeis olifera and Elaeis odora. Elaeis olifera is generally known as American palm oil. E. guineensis is native to West Africa occurring between Angola and Gambia, while American palm oil (Elaeis olifera) is native to tropical Central America and South America.

At present, palm oil exists in the wild, semi-wild, and cultivated forms, in three main areas of the equatorial tropical region. It is cultivated in 42 countries of the world and is largely used as edible cooking oil. The most important palm oil-growing countries include Indonesia, Malaysia, Thailand, Columbia, Nigeria, Papua New Guinea, Ecuador, Cote d’ Ivorie, India, and Congo.

Portuguese introduced palm oil into Brazil and other tropical countries during the fifteenth century, while Dutch imported palm oil seeds from Africa and planted four seedlings at Buitenzorg (Bogor) Botanical Gardens in Java, Indonesia, during the year 1848. Commercial planting of palm oil was started in Malaysia from 1917 onward.

Indonesia ranks first in the Palm oil production with 32.60 million tonnes with a productivity of 3.57 tonnes of oil per hectare, whereas Malaysia ranks second with the production of about 18.93 million tonnes with a productivity of 3.83 tonnes of oil produced per hectare. In India, the total fresh fruit bunches (FFB) production and crude palm oil (CPO) are 12.82 lakh tones and 2.17 lakh tones respectively of which 11.44 lakh tonnes of FFB and 1.93 lakh tonnes of CPO are produced from Andhra Pradesh only (Department of Agriculture and Cooperation, Ministry of Agriculture & Farmers Welfare, Government of India, New Delhi, 2015–2016). India’s share in the world’s palm oil production is only 0.20%. At present, in India, palm oil is cultivated in an area of about 3.01 lakh hectares with an average productivity of 30–35 tonnes of FFB/ha/year.

Palm oil is a tropical plant that grows commonly in the hot and humid tropical climatic conditions with optimal temperatures ranging from 80–90^o F. Henry [3] and Ferwerda [4] reported that an average daily temperature which is below 75°F is highly favorable for the cultivation of palm oil. Evenly distributed annual rainfall ranging from 2000 to 3000 mm is highly congenial for its growth and development. Zhu et al. [5] have reported that plants receiving direct sunlight of 5–7 hours per day have been found very much beneficial for optimal growth and development. Therefore, an adequate supply of water and the proper temperature has been identified as the most important factors in determining the yield of palm oil.

E. guineensis is a large pinnate leaved palm having a solitary columnar stem with short internodes. There are short spines on the leaf petiole and within the fruit bunch [6]. Palm oil is monoecious [7]—male and female inflorescences are produced separately on the same palm in cycles. The inflorescence is a compound spike or spadix carried on a stout peduncle and bears two large inflated bracts (spathes) that enclose the whole inflorescence. The inflorescences of both sexes are a compound spadix with 100–200 branches initially enclosed in a spathe or bract that splits 2 weeks prior to anthesis [8]. Palm oil is primarily pollinated by various insects [9] viz., weevil (Elaeidobius spp.) in Africa and Mystrops costaricensis and Elaeidobius spp. in Latin America. The African pollinating species Elaeidobius kamerunicus was introduced from Africa into the palm oil-growing regions of Asia and the Pacific in the early 1980s. These introduced weevils have assisted a lot in the successful pollination of palm oil and significantly improved the fruit set thereby increasing the yield [10, 11].

Palm oil fruit is a sessile drupe and borne on a large, compact bunch, varying in shape from nearly spherical to ovoid or elongate, and is 2–5 cm long and weighs about 3–30 g. The fruit pulp, which provides palm oil, surrounds a nut, the shell of which encloses the palm kernel. The seeding radical grows at a rate of about 4.5 mm/day to a maximum length of about 50 cm [12]. Purvis [13] observed roots penetrating down to a depth of about 3.0 m in Nigeria, while Jordan and Rey [12] observed primary roots extending to a depth of about 6.0 m in the Cote d’ Ivorie.

4.2 Ecophysiology of palm oil

Palm oil is traditionally grown in areas with an annual rainfall of more than 2000 mm and yields are always higher in countries such as Malaysia and Indonesia, which have more uniform rainfall compared with countries such as Nigeria, the Republic of Benin, and Ivory Coast which are noted for dry seasons. Irrigation tests conducted in these countries have shown positive responses to irrigation in terms of growth and yield. The availability of water in soils of palm oil plantations plays an important role in its proper growth [1] and serves as a signal for sex representation [14]. In areas where water is scarce, a large number of male flowers are observed to be produced, which is combined with slower growth rather than poor productivity. Basic information regarding water stress response in palm oil is a hot topic that needs to be further explored for controlling water tolerance. Water scarcity is a major biological stressor that spreads across the world over more than 1.2 billion hectares, especially in rainfed areas [15, 16, 17]. A dehydrated environment has been reported to be a major determinant of plant growth and development before the loss of productivity, especially crop species [18, 19, 20]. However, the basic knowledge of morphological, physiological, and biochemical responses in palm oil when exposed to water stress or deficit is still meager.

In India, palm oil was promoted as an irrigated crop, as the rainfall is much less than 2000 mm in most of the areas it is cultivated. It is estimated that about 150 mm of water per month is required by palm oil to meet its evaporation requirements. Under Indian conditions, several months of the year receive more or less rain, while the other few months receive heavy rainfall. A month that receives less than 150 mm of rainfall without sufficient water reserves in the soil is called a deficit month. When there is not enough water for evapotranspiration of palm oil, like other plants, this controls outflow loss by closing the stomata. When stomata are closed, photosynthetic activity is affected, affecting both growth and yield [21].

When evapotranspiration exceeds rainfall, the soil water content decreases and may reach a point at which the palm cannot extract water from the soil quickly enough for transpiration to continue at the potential rate. The palm will then start to suffer from water stress and the plant water potential will decrease. Under such situations, seasonal water deficit becomes the most important climatic factor affecting palm oil growth and yield.

A variety of different irrigation methods have been used for irrigating palm oil. The simplest and cheapest method is to control the water table level by flooding or blocking drains, but this is only applicable in relatively flat and low-lying areas. Other methods involve significant capital investment in the form of pumps and piping. Corley [22] suggested that drip irrigation might be less effective than sprinkler or flood irrigation. Plants subjected to water deficit not only show a general reduction in size but also exhibit characteristic modifications in their structure particularly the leaves with reduced cell division and leaf area. In such cases, stomata get closed early and gaseous exchange between plant and atmosphere stopped, and photosynthesis decreases earlier than the soil moisture potential reaches to permanent wilting point. Reduction in photosynthesis accompanied by increased respiration reduces assimilation in the plants and reduces the crop yield. Depending on the stage of crop growth, moisture stress has variable effects on physiological and biochemical processes.

In India, palm oil has been regarded as a smallholder’s crop under irrigated conditions that have a marked deviation from the traditional areas, viz., Malaysia, Indonesia, etc. where it is grown as a complete rainfed crop in larger nucleus estates. It is being grown in traditional areas with a well-distributed annual rainfall of over 2000 mm with no marked dry spells to areas of regular seasons with an accumulated water deficit of 600 mm per annum. The water deficit can be compensated by the provision of irrigation water. Also, palm oil requires a relative humidity of more than 45% for optimum transpiration. There will be a severe limitation of growth if the relative humidity is 30–35%. In addition to relative humidity, vapor pressure deficit also plays a vital role in influencing the growth rate, especially in the perennial crops.

Evapotranspiration is the sum of the evaporation and transpiration from plants. Transpiration is a continuous process caused by the evaporation of water from a palm leaf on one hand and its absorption by the roots into the soil on the other hand [23]. When evaporation exceeds the precipitation rate (rainfall or irrigation), a water deficit occurs. Groundwater deficit is the amount of water available from the soil in the active root zone of a crop. This is the actual amount of water needed to fill the root zone to bring the soil moisture level back to field capacity, which is the percentage of water remaining in the soil two or three days after the soil is saturated and the free drainage almost stops.

Water is an important component of plant tissues and a means of metabolism and metabolism in plants is essential for cell expansion by increasing its turgor pressure. In water deficiency, many physiological processes related to growth are affected and severe deficits can cause plant death. The effect of water deficit varies with the level and duration of water stress and the growth phase of palm oil. The leaf area can be reduced and this will reduce the amount of light that is intercepted. The reduced leaf water potential will close the stomata, so the plant will reduce its rate of transpiration, which is caused by an increase in leaf temperature, thus reducing biochemical processes. It will cause interference to separate the source and sink partitioning.

Even well-watered palms, as described by Corley [22], were found to close their stomata at noon when the sun was at its brightest and this could result in a 10% potential loss of yield. Despite high irrigation, low atmospheric pressures of relative humidity and high temperatures cause high vapor pressure (VPD) deficits, which can affect carbon accumulation. This was presented by Henson [24] who showed that the palm oil closed during the high VPD even though the soil moisture was not limited. Stomata begin to close when dehydrated, thereby affecting physiological processes [22]. Rees [25] showed that stomatal closure occurred during the second half of the day during the dry season under Nigerian conditions. Wormer and Ochs [26] reported that stomatal closure occurred during the dry season in Cote d’Ivorie. If the drought is prolonged, the palm can reach a critical threshold beyond which the water content of the tissue decreases rapidly. As a result, the leaflets get heated and dry out; hence, a large number of dried and broken leaves are observed as a result of severe stress. Finally, it entails the vegetative distribution lasting for several months or may cause the death of the palm.

4.3 Irrigation management in palm oil

Though palm oil is a typical humid tropical crop, it has been adapted to a wide range of climatic conditions ranging from tropical to semi-arid tropics. The climatic conditions prevailing in various palm oil-growing states of India are different from traditional palm oil-growing countries. In this context, irrigation management is one of the most critical aspects of palm oil cultivation. Irrigation is adopted to supplement the soil water reserve to meet the evapotranspiration demands of the crop, with an aim to increase plant growth and yield. A deficit or surplus of water would create stress on palm oil and adversely affect the yield of other crops. For palm oil irrigation without any deficit is considered optimum, which means that irrigation should be given at such rates and frequencies so that water is readily available for the plants with minimal losses.

4.4 Relationship between water deficits and yield in palm oil

Stage	Water deficit (mm/year)	Symptoms	Yield loss (%)
1	<200	Not a serious problem	0–10
2	200–300	Nonopening of immature and younger leaves, defective old leaves	10–20
3	300–400	Increased nonopening of younger leaves and defective leaves, drying of older leaves	20–30
4	400–500	Unopened immature leaves and dried leaflets	30–40
5	>500	Young leaves may not open, and leaf bud cracks and breaks	> 40

Irrigation trials conducted in different countries indicated that:

1. Yield response to irrigation increases with increasing levels of water deficit.

2. The increase in yield is due to an increase in the number of bunches with little or no effect on the bunch’s weight.

3. The increase in the number of bunches is due to the change in the ratio between the sex ratio and the decrease in bunch abortion.

4. The effects of irrigation can only be seen after several months (28 months) after the irrigation started.

4.5 Palm oil-sensitive stages for irrigation

Two sensitive phases of drought in palm oil are sexual differentiation (approximately 30 months before harvest) and abortion (approximately 10 months before harvest). The second drought-sensitive phase may coincide with the photoperiod-sensitive phase, making their distinction difficult.

Moisture stress during the above two stages will result in more male flowers and the abscission of female flowers. Hence, yields get decreased. Irrigation at these stages can effectively mitigate the adverse effect on the production of bunches thereby palm oil yield. It is documented that the effect of soil moisture deficits reveals only 1.5 to 2 years later on palm oil bunch yield by increasing the production of male inflorescences compared to that of female flowers and by including abortion of female inflorescence.

4.6 Water requirements of palm oil

The water requirement of a crop is the amount of water needed by the crop over a period of time for its optimal growth under field conditions. It is a function of precipitation, soil water reserves, and evaporation. Water demand varies from place to place depending on weather conditions such as hours of sunlight, temperature, and wind speed.

Crop	Water requirement (lakh liters/ha/year)
Palm oil	67.35
Banana	120.00
Sugarcane	133.00
Rice	300.00

Water requirement of palm oil compared to other irrigated crops.

5. Methods of irrigation in palm oil

5.1 Methods to estimate water deficit in palm oil

Irrigation is adopted to supplement the soil water reserve to meet the evapotranspiration demands of the crop, with an aim to increase the growth and yield.

5.1.1 Rainfall-based estimation

The difference between rainfall and evaporation indicates the soil water deficit. To quantify the water stress, one should have potential evapotranspiration of the crop.

Water deficit for a period can be calculated by the given formula.

$$\text{D}=\text{R}+\text{P}–\text{PE}$$

where D is the water deficit factor, R is the theoretical reserve, P is the rainfall, and PE is the potential evaporation.

5.1.2 Crop factor-based estimation

It is the best available method to estimate crop water requirement from direct measurements of crop evaporation. Water requirements of crops are closely related to evaporation (evaporation of water from the soil surface) and transpiration (evaporation of water through leaves) when combined called evapotranspiration. Evaporation can be easily measured but transpiration is not. Therefore, it is much simpler to relate crop evapotranspiration to daily evaporation via crop factor. In this method, penman’s estimate of evaporation is multiplied by the appropriate crop factor to estimate the potential evapotranspiration.

A crop factor can be defined as the percent of ground covered by the crop canopy, which varies according to the crop and stage of the crop. For palm oil, the internationally approved crop factor for an adult palm is 0.7.

The following simple method of calculation has been devised based on the evaporation rates prevailing in the area, especially during the summer months. For example, the highest average of pan evaporation during peak summer months is taken as 6.70 mm. The requirement of water per palm per day is estimated as follows:

Evaporation from open pan: 6.70 mm.

Crop factor: 0.7.

$$\text{Potential evapotranspiration}\left(\text{PE}\right)=\text{Pan}\text{evaporation}\times \text{Crop factor}$$

$$PE=6.07\times 0.7=4.69mm/day$$

As 1 mm of rainfall is equal to 1 L/m² = 46,900 l/day/ha.

Since 143 palm trees are planted on one hectare of land, the amount of water per palm tree per day is up to 328 liters.

Water storage capacity of not less than 70% of field capacity is acceptable and will not significantly affect the FFB yield of palm oil.

Therefore, the amount of water to be applied will be:

$$4.69mm\times 70\%=3.283mm/dayor32.830lit./ha/dayor230lit./palm/day$$

5.2 Processing of palm oil

The first fruit bunches ripen 3–4 years after planting. Normally palm oil takes about 180 days from the time of emergence of the inflorescence to the maturation of palm oil fruit bunch. The majority of the oil formation in the fruits takes place during the last 2–3 weeks of fruit ripening. Harvesting of over-ripe fruits results in poor-quality oil with high FFA content. Palm oil fruits contain an enzyme called lipase, which splits the oil into undesirable free fatty acids leading to quality problems during storage, processing, and refining. Care must be taken to cause minimum damage to the fruit bunches and transportation of harvested fruit bunches to the processing unit with a minimum delay to reduce the activity of enzyme lipase.

5.3 Oil biosynthesis

Young fruits during the first two weeks of development contain very little lipids (5–10% per fresh weight). Storage of oil synthesis in palm oil mesocarp can be detected as early as 12 weeks after anthesis. A high rate of oil accumulation begins at 16 weeks and stops when the fruits ripen about 20 weeks after anthesis. Oil is stored in oil bodies found in the cytoplasm of mesocarp cells of ripe fruits. Small oil bodies may already be observed at about 13 weeks after flowering when oil synthesis begins. Oil accumulation in kernel begins about 12 weeks after flowering and stops at 14 weeks. During this time, the kernel gradually hardens [2]. The fatty acids in the mesocarp of young fruits consist mainly of polyunsaturated linolenic acid (18: 3) and linoleic acid (18: 2). When rapid oil accumulation begins the level of linolenic drops to an insignificant value, while the level of linoleic also drops but is stably maintained at 10% in ripe fruits.

Quartering is the process in which the fruit bunches are cut into smaller portions followed by stripping or loosening of the fruits from the bunch and spikelets.

Processing of palm oil fruits for edible oil has been practiced in many countries. Crude palm oil (CPO) is obtained from the fruit of the palm oil tree (Elaeis guineensis), which is a rich source of palmitic acid, β-carotene and vitamin E. Extraction of palm oil from fresh fruit bunches (FFB) involves field and factory operations. The techniques for processing palm oil fruit vary with available technology, and this will greatly influence the type and quality of the oil produced. The extraction of oils from freshly harvested fruit bunches involves five major operations: sterilization, fruit loosening, digestion, oil extraction, and clarification.\

5.4 Sterilization of fruits

Sterilization or cooking is the process to use high-temperature wet heat treatment to loosen the fruits from the bunch. Stripping prevents free fatty acids build up in the oil and softens the fruits in the bunch to facilitate easy striping. The heat that is produced during sterilization destroys the lipase enzyme and arrests hydrolysis and autoxidation. Heat produced during sterilization will coagulate the nitrogenous and mucilaginous matters to prevent the formation 0f emulsions in the crude palm oil during the process of purification. It also helps in breaking up the oil-carrying cells of the mesocarp to release the oil during the digestion process.

5.5 Stripping or loosening of the fruits

Fruit stripping or loosening refers to the separation of fruits from the bunch and spikelets. Traditionally, it is performed by removing the fruits from the spikelets one by one even though it is a time-consuming process the fruits collected are clean and free from bruises. In the case of a mechanized system, rotary drum equipped with rotary beater bars detaches the fruits from the bunch leaving the spikelets on the stem. Stripping is carried out immediately after sterilization.

5.6 Fruit digestion

Fruit digestion means size reduction and it is a wet communication process involving the detachment of the steamed or heat-weakened mesocarp from fruit nuts. Digestion is to break up the pulp of the fruit and liberate oil from the cells. The extent of digestion of the fruit determines the degree of exposure of oil cells. Horizontal and vertical digesters are used for the process of digestion. Digesting the fruits at a high temperature helps to reduce the viscosity of the oil, destroys the outer fruit covering, and completes the disruption of the oil cells, which has already begun in the sterilization phase. The yield of oil greatly depends upon the method of digestion.

5.7 Separation or oil extraction

Oil separation is the process that separates the crude palm oil from the mash. In small-scale system, oil separation is achieved by combining digested screw press, hydraulic press, and hand spindle press, which are regarded as dry pressing (squeezing the oil out of a mixture of oil, moisture, fiber, and nuts by applying mechanical pressure on the digested mash). The other method is the wet method which uses hot water to leach out the oil.

5.8 Clarification and drying of oil

Last step is the processing of palm oil which separates the pure oil from the sludge in the boilers. Clarification is achieved by the separation of oil from water and other materials, the development of the characteristic product flavor, and purification of oil from contaminants. The oil from the clarification tank still contains 0.40–0.60% water and 0.10–0.20% of the sludge and other impurities that affect the quality of oil. The bulk of the water and the impurities are removed by centrifugation to bring down the moisture level. Further reduction of moisture to the optimum level of 0.1–0.15% is achieved by vacuum drying.

5.9 Refining

Refining of crude palm oil (CPO) is carried out for removing impurities, free fatty acids, color, and odor. This is achieved through 2 routes, chemical and physical refining.

5.10 Chemical refining

Major unit operations involved are degumming, neutralization and soap stock preparation, bleaching and filterations, deodourisation, and polishing.

5.11 Degumming

The precipitation process in which the impurities such as phosphates, protein fragments, and mucilaginous substances are removed. Degummed oil is treated with a calculated amount of caustic soda to remove free fatty acids in the form of soap. The soap water was separated by centrifugation, and the neutral oil was washed out of the alkali and soap using hot water at a temperature of 90°C, then by vacuum drying.

5.12 Bleaching

It is done to obtain palm oil with a lighter color and to remove traces of soap. Depending upon the crude palm oil 1–3% of bleaching earth at a temperature ranging from 100 to 150°C under vacuum for 15–30 minutes is employed.

5.13 Deodourisation and polishing

It is achieved by passing superheated steam at 230–240°C under vacuum for 2 hours and the oil is cooled to 55^°C and pumped through a polishing filter to give the oil its final sparkle.

5.14 Physical refining

Operations involved in physical refining are degumming, bleaching, filtration, steam stripping, deodourisation, and polishing. Crude palm oil is mixed with 0.21% phosphoric acid followed by bleaching with 1–2% earth under vacuum at 100–150°C and the spent earth is removed by filtration. The refined and bleached oil was deaerated and steamed under a vacuum at 240–2270°C. Finally, the oil is cooled and passed through a polishing filter. The physical method will yield better-quality oil and avoid contamination. The final product of both refining methods is the same viz., refined and deodorized palm oil (RBDPO).

6. Conclusion

Palm oil is the highest edible oil-yielding crop among vegetable oils giving up to 4.0–5.0 tonnes/ha/year under good agricultural management practices [1]. Palm oil is well received by consumers, especially as a cooking utensil because of its cost-effectiveness. It is a good raw material used for the production of oleo chemicals used in cosmetics, medicine, nutrition, etc. In general, it can be said that palm oil is a source of health and nutrition improvement, value addition, recycling of environmentally friendly waste, diversified sources, import substitution, creation, and sustainability.