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Barley (Hordeum vulgare L) is one of the major cereal grains grown in temperate countries and ranked globally as the fourth largest grain crop. Currently, it is produced in more than 100 countries around the world with a global production of approximatively 159 million tonnes and 51 million hectares in 2019. The production and value-added barley products impact breweries, food processors, feed mills, and livestock operations. Barley grain is used primarily as an energy and protein source in beef cattle diets and as a malt source for alcoholic beverages, especially in the beer industry. Also, barley is used in bread, soups, stews, and health products since the barley grain is rich in several health-boosting components. As such, barley is high in protein, fibre, vitamins and natural bioactive antioxidants such as phenolics and lipids. However the studies of bioactive and nutritional properties of barley and the utilization of the crop as a functional food in animal and human diet is still limited. The work herein provides a review covering world production, end-use and processing, nutritional attributes, and will advocate its potential as a functional food for animal and human health and its role in preventing some chronic diseases.
Agriculture and Agri-Food Canada, Brandon Research and Development Centre, Canada
Champa Wijekoon
Agriculture and Agri-Food Canada, Morden Research and Development Centre, Canadian Centre for Agri-food Research in Health and Medicine, Canada
*Address all correspondence to: ana.badea@canada.ca
1. Introduction
Barley (Hordeum vulgare L) was domesticated in approximately 10,000 BC and is considered one of the oldest cultivated grains [1]. While the Fertile Crescent is widely accepted as the center of origin through the years, there were numerous debates, for example, regarding the number of times and locations [2, 3, 4, 5] that barley was domesticated, the number of wild barley populations descended from [6, 7] and so on. Relatively recent, comparative genomic analysis of 6,000-year-old barley grains, found in a cave in the Judean Desert, and modern Israeli landraces showed close affinity and supported the previously proposed location, Jordan Valley, as the origin of the domesticated barley [8]. Moreover, the availability of additional barley reference genomes such as those recently reported by [9] may also help elucidate some of these controversies [10].
Currently, barley ranks fourth in both quantities produced and in the area cultivated for cereal crops globally. It was presumably first used as human food but evolved primarily into a feed, malting and brewing grain, in part due to the rise in prominence of wheat and rice [11]. Due to its ability to be cultivated in a wide range of climates, the crop is essential in places in the world where food security is an issue [12]. Moreover, barley has also been used as a principal food source in places where other cereals are more challenging to grow [13].
Barley is classified as spring or winter type, two-row or six-row, hulled or hulless, and malting or feed by end-use (Figure 1). Based on grain composition, barley is further classified as normal, waxy or high amylose starch types, high lysine, high beta-glucan, and proanthocyanidin-free types [14]. It has been shown that both genetics and environment could affect the overall metabolite composition of the barley and subsequent malt [15]. For example, [16] demonstrated a direct association between barley genotype and beer flavour, independent of the malt quality traits.
Figure 1.
Examples of different types of barley: two-row (upper left), six-row (upper right), hulled (bottom left) and hulless (bottom right). Source: authors’ personal photo collection.
One of the most genetically diverse cereal grains, barley, is also considered a model plant in research allowing advances in plant genetics, plant physiology, plant pathology, plant biochemistry, and plant biotechnology [17]. Genetic diversity provides an ample opportunity to identify and breed barley varieties for specific end-uses for processors.
Barley is used as feed in ruminant, swine, poultry, and aquaculture production. As reported by [18] compared to feed grain corn, besides offering greater protein, barley grain is also richer in methionine, lysine, cysteine, and tryptophan. Moreover, compared to corn, due to its more rapid starch fermentation rate, barley provides a more simultaneous release of energy and nitrogen, consequently improving the microbial nutrient assimilation. The benefits of using fermented barley grain in the diets of broilers were also demonstrated. Fermented barley is considered a valuable functional ingredient that can improve performance, breast meat quality, and intestinal health of birds [19].
Nowadays, human health and well-being are foremost. Therefore balanced nutrition and diet are receiving more and more attention. In this context, functional foods are much sought. Beyond meeting basic nutrients, these foods also provide additional health benefits by promoting and combating chronic diseases [20]. Thus, barley grain is gaining renewed attention worldwide due to the richness in functional ingredients. In particular, the nutritional composition meets the needs of a diet high in protein, fibre and vitamins, and low in fat and sugar [21]. The increase in the use of barley and malt in processed foods is mainly due to its natural antioxidants and the unique soluble fibre beta-glucan [22]. Barley is rich in groups of bioactive compounds, including phenolics and lipids, that have potential health benefits [23]. The epidemiological studies have shown that long-term consumption of diets rich in barley flour can offer protection against the development of hyperlipidemia, diabetes, and atherosclerosis [24]. The phenolic compounds found in barley, such as cinnamic acid derivatives and benzoic, proanthocyanidins, flavonols, flavanones, and flavones, could have beneficial effects, antioxidative and antitumor, decreasing blood lipids and hypoglycemic, on human health [22, 25]. In addition, the consumption of barley is an important source of macro- and micro-nutrients that is needed in the typical human diet and has beneficial effects against the development of illnesses such as cardiovascular disease, diabetes, and cancer [26].
Barley is very versatile and has adapted well throughout its evolution. Its high prevalence is likely due to its high adaptability to a variety of climates, including cold and drought, and its adaptability to poor soil conditions compared to wheat. Much of the world’s barley is produced in the regions where cereals such as maize and rice cannot grow well [27].
To date, barley is produced by more than 100 countries around the world [28]. In 2019, the global barley production was approximatively equal to 159 million tonnes (M t), after rice (755 M t), wheat (765 M t), and corn (1,148 M t). From 1961 to 2019, the average global production was 142 M t, with the highest production of 178 M t recorded in 1990 (Figure 2). In 2019, Europe accounted for more than 60% of the global barley produced, followed by Asia (16%) and North and Central America (9%) (Figure 3). Among the European barley producers, the Russian Federation, France, and Germany have exceeded, on average, 10% each for the past ten years. Australia and Canada follow them at 8.9% and 8.4%, respectively (Table 1).
Figure 2.
Global top cereal crops production (M t), 1961–2019. Source: prepared based on data from [28].
Figure 3.
Global barley production (M t) by region, 2019. Source: prepared based on data from [28].
Country
Year
Average
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
Russian Federation
8.3
16.9
13.9
15.3
20.4
17.5
17.9
20.6
16.9
20.4
16.8
France
10.1
8.7
11.3
10.3
11.7
13.0
10.4
12.0
11.0
13.5
11.2
Germany
10.3
8.7
10.3
10.3
11.5
11.6
10.7
10.8
9.5
11.5
10.5
Australia
7.8
7.9
8.2
7.4
9.1
8.6
8.9
13.5
9.2
8.8
8.9
Canada
7.6
7.8
8.0
10.2
7.1
8.2
8.8
7.8
8.3
10.3
8.4
Ukraine
8.4
9.0
6.9
7.5
9.0
8.2
9.4
8.2
7.3
8.9
8.3
Spain
8.1
8.2
5.9
10.0
6.9
6.7
9.1
5.7
9.5
7.7
7.8
Turkey
7.2
7.6
7.1
7.9
6.3
8.0
6.7
7.1
7.0
7.6
7.3
United Kingdom
5.2
5.4
5.5
7.0
6.9
7.3
6.6
7.1
6.5
8.0
6.6
Argentina
2.9
4.0
5.1
4.7
2.9
2.9
4.9
3.7
5.0
5.1
4.1
Table 1.
Global top barley producers (M t), 2010–2019.
United Kingdom of Great Britain and Northern Ireland; Source: prepared based on data from [28].
In 2019, the total area harvested for barley was 51 million hectares (M ha) and ranked fourth after rice (162 M ha), corn (197 M ha) and wheat (216 M ha). Over the past six decades, barley maintained its position in the global top five most cultivated cereal crops, and its harvested area ranged from 50 to 80 M ha, with the highest reached in 1979 at nearly 84 M ha (Figure 4).
Figure 4.
Global top cereal crops area harvested (M ha), 1961–2019. Source: prepared based on data from [28].
In 2019, barley yield was 3.1 tonnes per hectares (t/ha) and ranked fourth after wheat (3.5 t/ha), rice (4.7 t/ha), and corn (5.8 t/ha). The average yield of the top cereal crops has been continuously increasing since 1961. During this period, barley yield averaged 1.8 t/ha in the ‘60s and ‘70s, 2.2 t/ha in the ‘80s and ‘90s, and 2.7 t/ha since the 2000s. In 2016, it broke the 3 t/ha barrier, with the highest yield reached in 2019 at 3.1 t/ha (Figure 5).
Figure 5.
Global top cereal crops grain yield (t/ha), 1961–2019. Source: prepared based on data from [28].
Different barley classes often differ in physical and compositional characteristics and accordingly have different processing properties and end-use quality. Overall, worldwide barley has three primary uses: malting, feed, and food (Figure 6). In most countries, the majority portion of the barley is used as animal feed, particularly for cattle and pigs, and the use of barley as human food is more limited [13]. Although feed is the main use of barley, in many instances, more value comes from the crop if it is used for malting and production of beverages such as beer and whiskey [12]. However, barley is still considered a major staple food in several regions such as some areas of North Africa and the Near East, in highlands of Central Asia, the Horn of Africa, the Andean countries and the Baltic States, which are characterized by harsh living conditions. In 2016, per capita consumption was reported to be the highest in North Africa, with Morocco at 41 kg/person, Ethiopia and Syria at 15 kg each [30]. By contrast, very little barley is used as human food in developed countries. Overall, in 2016, the global per capita food use of barley was estimated at 1 kg/person compared to 17 kg of maize, 54 kg of rice and 67 kg of wheat. However, there is renewed interest throughout the world in barley food because of its nutritional value [14]. During the past decade, of the total global barley consumption, about 65% is used as feed, followed by industrial at about 20%, which includes malting. A smaller percentage is used for food (5%) as well as some for other uses (7%) (Figure 7).
Figure 6.
Main end-uses of barley grain, worldwide. Source: elaborated from [29].
Figure 7.
Global consumption of barley grain by end-uses (M t), 2011–2020. Source: prepared based on data from [31].
The processing (e.g. rolling, grinding, flaking) improves the digestibility of barley grain. For example, whole barley grain is 15 to 30% less digestible than the same barley grain when dry rolled [32]. Studies showed that the barley starch is readily degradable for ruminants without gelatinization, unlike corn that requires steam-flaking to make starch available by breaking down the protein that surrounds starch granules within the endosperm [33].
After the inedible outer shell has been removed during processing, the barley grain is considered a healthy whole grain. The more commonly available pearled barley is not a whole grain because the fibre-containing bran has been removed [34]. Despite that, pearled barley still has a high beta-glucan content (Figure 8). When assessing the content and distribution of beta-glucan of low and high beta-glucan barley genotypes, [36] found that the highest content was in the subaleurone region, in the case of low beta-glucan barleys, while in the high beta-glucan ones, it was distributed more evenly throughout the endosperm.
Figure 8.
Nutritional profiles of pearled barley vs. whole grain. Source: prepared based on data from [35].
A significant high-value use of barley is in producing malt as a raw material for the brewing and distilling industries. In short, the malted barley is barley grains that have been made to germinate and then stopped from further germination by drying. The process comprises five stages: barley grading and cleaning, steeping, germination, kilning and malt cleaning and grading. To obtain 100 kg of malt approximately 120 to 130 kg of screened barley are necessary, depending on grain quality and purity. The average ratio used is 1.267 [37]. The contribution of barley to beer flavour is primarily developed through the malting process, as well as its macro-chemical contribution to brewing [38]. Barley malt provides saccharides, proteins, free amino nitrogen, and enzymes that facilitate fermentation reactions in brewing, and the malt quality traits can influence the flavour of the beer [39].
The nutrient composition of barley grain varies with the cultivar, environment, and processing [34]. In the last two decades, we have seen a rediscovery of food preparations with barley with a significant increase of use and may be due to recently developed barley varieties that are rich in nutrient composition [39]. The composition and nutritional attributes of barley as food and feed are described below.
4.1 Carbohydrates and fiber
Barley starch content is nearly 20% lower than that of wheat or corn grain [14]. It has been reported that hulled or hulless regular varieties have higher starch contents than hulled or hulless waxy barley grain cultivars. For example, the waxy or regular barley is determined by the composition of amylose to amylopectin levels. Thus, regular barley typically has a ratio of amylose to amylopectin of 1:3, whereas waxy barley contains higher amylopectin levels (up to 100%) [34].
Beta-glucan is one of the non-starch water-soluble fiber in barley grain. The beta-glucan content varies in different barley varieties from 2 and 11% in dry grain [40]. For example, 1.2 to 6.7% in hulled varieties and 4.6 to 7.3% for regular versus waxy barley, and hulless varieties ranging from 2.8 to 7.3% DM (non-waxy) and 4.8 to 16.9% DM (waxy) [34]. The water-insoluble fibre in barley is comprised of lignin and other non-starch polysaccharides, such as cellulose and hemicellulose, that are concentrated in the hull of the grain. The total fibre contents are different between hulled (13.2 to 27.0 vs. 19.6 to 22.6% DM; regular vs. waxy) and hulless (9.4 to 20.2 vs. 12.6 to 33.4% DM, regular vs. waxy) barley varieties concentrated in the endosperm cell walls. It is considered that due to the hull, barley grain provides greater dietary fibre than wheat or corn, and a larger portion of the fibre is in an insoluble form [41].
4.2 Proteins and amino acids
Barley grain protein content is an important quality factor determining grain end-use value [42]. Prolamins are a class of storage proteins that account for up to 70% of the total protein in barley, however, the amino acid composition of prolamins is characterized by high levels of glutamine, proline and low amounts of essential amino acids such as lysine, threonine and tryptophan [43]. A recent study on the comparative proteomics analysis between the six-row and two-row barley cultivars indicated that 20 proteins were differentially abundant between the two cultivars [44]. Variation in the abundances of hordoindoline proteins was one of the key differences between them, and the authors suggested that the type of hordoindoline proteins may contribute to the differences between the seed hardness of these two cultivars.
In a 2018 survey, conducted in Western Canada, where barley plays a prominent role as a source of feed for both ruminants and monogastric farm animals, it was found that the average crude protein content is higher than the average found in corn, rye, and oats [45]. Earlier, [34] also reported that barley has 4% higher protein content than corn grain. Also, [46] investigated the grain protein concentration and harvestable protein under future climate conditions on a large collection of barley accessions and reported that despite the increase in grain protein concentration (5% at elevated temperature and 29% at elevated CO2), the decrease in grain yield under the predicted future climate conditions resulted in 23% less harvestable protein. However, variation in the reponse of the barley accessions tested was observed and could be exploited.
4.3 Vitamins
Vitamins in barley include B1, B2, B3, E and gamma-aminobutyric acid, which may vary based on the cultivars. For example, it was shown that vitamins B1 and B2 were the most variable within a barley collection from Tibet, China [47]. Vitamin B1 was present as the highest proportion, followed by B2 and E, while B3 was present as the lowest proportion in the collection. The content in gamma-aminobutyric acid was also highly variable. Moreover, it was found that the content of vitamins B1, B2 and C, and proteins increased notably after germination [48].
4.4 Phenolic compounds
Barley is a good source of phenolic compounds, which can be found free as well as bound to fibre [49]. Phenolic compounds in barley include monophenol, phenolic acids, flavonoids and other polyphenols [22]. The flavanols, such as catechin, procyanidins and prodelphinidins, are the main compounds in the free phenolic fraction of barley grain, while phenolic acids, such as ferulic, coumaric and vanillic acids, are major constituents of the bound phenolic fraction [49, 50, 51]. However, ferulic acid is the most abundant hydroxycinnamic acid found in barley and accounts for up to 90% of total polyphenols [52]. Flavanols, anthocyanins, and proanthocyanidins (polymers of flavonoids) are the major types of flavonoids found in barley grains (Table 2). Flavanols are located in the pericarp of barley grains, while anthocyanins are water-soluble vacuolar pigments mainly present in the pericarp or the aleurone layers of barley grain, causing purple or blue hues of kernel colour [61]. Anthocyanins in barley include cyanidin, cyanidin 3-glucoside, delphinidin, pelargonidin, pelargonidin glycosides, and petunidin 3-glucoside [60]. It was reported that the bran-rich fraction of barley grain contained the most flavonoid content, whereas the hull fraction did not contain any significant flavonoid content [62]. Out of major proanthocyanidins in barley, prodelphinidin B3 (90–197 μg/g) accounted for the majority of proanthocyanidins, whereas procyanidin C2 (5–19 μg/g) was reported to be present only in minor quantities [63]. In the malting process, the green malt had the highest antioxidant activity (79.80%) and total phenolic content (122.43 mg/100 g) than those of barley and malt [64]. For example, carotenoid (1.71 μg/g), (+)-catechin (69.06 mg/100 g), 1,2-dihydroxybenzene (37.21 mg/100 g), quercetin (30.78 mg/100 g) and isorhamnetin (22.44 mg/100 g) contents were higher in green malt.
Barley lipids include fatty acids, phytosterols and tocols (Table 3). A recent study comparing Irish barley varieties showed that linoleic acid is one of the most abundant unsaturated fatty acid, while phytosterols vary, beta-sitosterol being the most abundant sterol, and alpha-tocotrienol is the most abundant tocol homologue [72]. Tocopherols and tocotrienols (Vitamin E), also called tocols, are known to have several chemical and physiological properties in barley [49]. Besides, [73] showed that the total lipid content and fatty acid composition varies with the barley variety and decreases during the malting process. However, a study showed that barley lipids contained 18.53% palmitic, 19.94% oleic and 51.74% linoleic acids while malt oil contained 17.33% palmitic, 15.62% oleic and 56.56% linoleic acids, and linoleic acid content increased during the malting process while oleic and palmitic acid content decreased [64].
Compound
Mean
Health benefit
Reference
Tocols (μg/g) Beta-Tocopherol Delta-Tocotrienol
61.49 0.22 1.01
Protection against toxins, neurological diseases like Alzheimer’s disease, diabetes, and modulating degenerative diseases such as cancer and cardiovascular diseases
5. Potential of barley as a functional food for animal and human health
The human lifestyle, including diet composition and the pattern of physical activities, have undergone a major shift since the last millennium. In recent years, it has been well documented that healthy eating practices, maintaining a normal body weight, controlled blood pressure, and regular physical activity could prevent up to 80% of coronary heart disease, 90% of type-2 diabetes and one-third of all cancers [74]. Consumers are becoming more aware of the relationship between diet and disease, and there is an ongoing shift from animal-derived to plant-based meals. Thus, globally, more effort in developing novel, healthier, more nutritious and fortified functional foods is invested nowadays. Likewise, continuous efforts are made to ensure the health and well-being of animals raised for food since this is a critical component of providing safe food products. For example, use of bioactive compounds are encouraged since they have similar proprieties as withdrawn antibiotic growth promoters [75]. Additionally, [76] demonstrated the transfer efficiency of tocotrienols from barley into egg yolk when offered as a dietary supplement and signalled the possibility of developing hen’s eggs that are nutritionally-enriched in specific health-promoting tocotrienols.
Barley, which recently is seeing renewed interest, is a versatile crop used both for human nutrition and as an animal feed for energy and nutrients [11, 17] due to its high content of biologically active constituents such as dietary fibre, especially beta-glucan, tocols, including tocopherols and tocotrienols, and phenolic compounds.
5.1 Benefits of barley as an animal feed
The nutritional quality of barley grain fed to animals is traditionally defined by energy content [77]. Accurate and rapid evaluation of the energy content of barley is key to ensure the optimum nutrient content of the barley as an animal feed. Usually, barley is fed to beef cows when they graze poor-quality pastures to increase the energy content of their diet [34]. Beef cattle could be fed barley either as whole or processed, with the last one providing greater animal performance. Barley is also considered suitable for inclusion in the diet of all types and ages of poultry, with older birds being more able to utilize barley than younger chicks. Inclusion of whole barley grain in broiler diets has been reported and may be cost-effective due to limited processing required [78]. Barley has been suggested to be included in the diets of horses, rabbits, and fish to provide energy and nutrients. However, the level of inclusion may need to take into consideration the digestive physiology of the animal and its ability to digest fibre [34].
High levels of insoluble dietary fibre can increase fecal bulk due to its high water holding capacity [79]. In animal nutrition, high-amylose barley is associated with enzymatic resistance to digestion in swine and poultry, contributing to slower glucose release and prolonged satiety. In addition, increased amylopectin is associated with faster digestion of starch to glucose, which may result in higher feed intake due to rapid rises in insulin [34].
While it was demonstrated earlier that the use of fermented barley is a valuable functional ingredient for broilers diets [19], recently it was shown that feeding fermented barley can also be a possible nutritional strategy for managing nursery pigs without in-feed antimicrobial growth promoters [80]. It has been suggested that feeding high-barley diets to finisher pigs may improve pork quality attributes compared with feeding corn since barley has lower fat and linoleic acid content than corn, resulting in firmer and whiter pork fat, increasing its contrast with myoglobin and thus enhancing the visual appeal of loin marbling [81].
5.2 Health benefits of barley for humans
Barley can be breakfast, lunch, or dinner. However, it surpasses the meals since it has unique advantages. The renewed interest in barley grain is mainly due to its unique soluble fibre beta-glucan and antioxidant phytochemicals (Figure 9).
Figure 9.
Barley grain anatomy and the distribution of the key biologically-active phytochemicals within the barley grain. Source: elaborated from [82].
The effectiveness of barley beta-glucan in barley food products in lowering blood cholesterol [83, 84, 85, 86, 87] and glycemic index [88, 89, 90, 91] has been reported in numerous studies. Therefore, foods containing substantial levels of barley beta-glucan are considered functional foods, and in several countries, they are permitted to carry health claims. So far, barley health claims have been approved by the US Food and Drug Administration (FDA) (2006), European Food Safety Authority (EFSA) (2011), Health Canada (2012), and more recently by Food Standards Australia and New Zealand (FSANZ) (2017) [92, 93, 94, 95].
Besides health-benefiting beta-glucan, barley contains phytochemicals in varying concentrations, usually determined by genotypic or environmental factors or the interaction of both factors [60]. These phytochemicals in barley may exist in free, conjugated, or bound forms, categorized into several major classes, including phenolic acids, flavonoids, lignans, tocols, phytosterols, and folates [96]. Tocols are components.
of plant oils that provide benefits such as protection against toxins, neurological diseases like Alzheimer’s disease, and diabetes [60]. For example, barley is a rich source of tocols, including tocopherols and tocotrienols. When assessing the grains of 16 feed/food barley genotypes, it was found that on average, the total tocols were 69.8 μg/g, with tocotrienols being the most abundant averaging 53.10 μg/g, while tocopherols were averaging only 16.69 μg/g (Figure 10). The genotype was found to significantly affect the content of all individual tocols, combined tocopherols, combined tocotrienols, and total tocols for those barley genotypes [97]. In addition to their antioxidant properties known to reduce serum low-density lipoprotein cholesterol [98, 99], the tocol content of cereals such as barley can confer health benefits, including modulating degenerative diseases such as cancer and cardiovascular diseases [65]. Also, [67] suggested that alpha-tocotrienol and polyunsaturated fatty acids are hypocholesterolemic components in barley oil. Furthermore, studies indicate that a high intake of alpha-tocopherol decreases lipid peroxidation and platelet aggregation, functioning as a potent anti-inflammatory agent [49, 100]. Recent studies showed a significant correlation between phenolic components and antioxidation especially suggesting that coloured barley grains are rich in phenolic compounds with antioxidant capacity [22, 49]. It was also reported by [101] that the free and bound phenolic extracts in the blue hulless barley grains have an equivalent proportion in the total phenol and co-exist in two forms. The bound forms of barley grain phenols contribute to the antioxidative and antiproliferative activity against cancer cells in the human liver. Their high concentration in barley may be responsible for its usefulness in controlling certain diseases [21, 60]. For instance, a phenolic acid named ferulic acid in barley has a wide range of health benefits, including anti-inflammatory, therapeutic usage, antidiabetic, anticancer, antiapoptotic, antiageing, hepatoprotective, neuroprotective, radioprotective, pulmonary protective, hypotensive effect, and antiatherogenic [58, 102]. Coumaric acid has anti-inflammatory, anticancer, antimicrobial and antioxidant effects, and by decreasing low-density lipoprotein peroxidation, coumaric acid has a protective role against heart diseases [59, 103]. Vanillic acid is considered a bioactive molecule for treating inflammatory diseases [54, 55]. In addition, sinapic acid can attenuate various chemically induced toxicities [57], whereas syringic acid shows a wide range of therapeutic applications in preventing diabetes, cardiovascular diseases, cancer and cerebral ischemia [56].
Figure 10.
Average of individual and total tocopherols and tocotrienols in the barley whole grain. Source: prepared based on data from [97].
Studies have consistently shown that regular consumption of barley whole grain reduces the risk of developing chronic heart diseases, cancer, and gallstones [60, 104, 105, 106]. Based on an recent pre-clinical study, it was demonstrated that lifelong barley intake could positively contribute to healthy ageing [107]. It was found that barley intake prolonged the lifespan, delayed locomotor atrophy, reduced loss of balancing ability and spatial recognition and significantly increased the particle sizes of high-density lipoprotein cholesterol, which is associated with a reduced risk of total stroke.
Barley is one of the first cultivated crops, globally grown in diverse soil conditions and in areas where other crops cannot be easily cultivated. Although the crop is primarily grown as an animal feed and as a source of malt for alcoholic beverages, more and more it is included as a component of various foods due to the health benefits attributed mostly to dietary fibre, lipids, vitamins and antioxidant phytochemicals. These components are broadly distributed in barley and play an important role as substrates in the biosynthesis of various metabolic compounds and influence the flavour, taste, and colour of foods. Nutritional attributes of barley contribute to the prevention of numerous metabolite disorders providing antioxidant, anti-carcinogenic, anti-inflammatory, and cardio- and neuro-protective effects. Overall, having barley in animal and human diets showed beneficial effects against the development of chronic illnesses.
This work was supported by Agriculture and Agri-Food Canada and the National Barley Cluster (Alberta Barley Commission, Brewing and Malting Barley Research Institute, Manitoba Crop Alliance, Saskatchewan Barley Development Commission, Western Grains Research Foundation, and Agriculture and Agri-Food Canada) led by the Barley Council of Canada through the Canadian Agricultural Partnership.
Thank you to the Editor, Dr. Goyal, for the kind invitation to write this book chapter review.
References
1.Zohary D, Hopf M, Weiss E. Domestication of plants in the Old World: The origin and spread of domesticated plants in Southwest Asia, Europe, and the Mediterranean Basin. Oxford University Press on Demand. 2012. DOI: 10.1093/acprof:osobl/9780199549061.001.0001
2.Badr A, Müller K, Schäfer-Pregl R, Rabey HE, Effgen S, Ibrahim HH et al. On the origin and domestication history of barley (Hordeum vulgare). Mol Biol Evol. 2000;17:499-510. DOI: https://doi.org/10.1093/oxfordjournals.molbev.a026330
3.Dai F, Nevo E, Wu D, Comadran J, Zhou M, Qiu L, Chen Z, Beiles A, Chen G, Zhang G. Tibet is one of the centers of domestication of cultivated barley. Proc Natl Acad Sci USA. 2012;109:16969-16973. DOI: 10.1073/pnas.1215265109
4.Wang Y, Ren X, Sun D, Sun G. Origin of worldwide cultivated barley revealed by NAM-1 gene and grain protein content. Front Plant Sci. 2015;6:803. DOI: 10.3389/fpls.2015.00803
5.Molina-Cano JL, Conde J. Hordeum spontaneum C. Kochem. Bacht, collected in southern Morocco. Barley Genet News.1980;10:44-47
6.Poets AM, Fang Z, Clegg MT, Morrell PL. Barley landraces are characterized by geographically heterogeneous genomic origins. Genome Biol. 2015;16:173. DOI: 10.1186/s13059-015-0712-3
7.Pankin A, Altmüller J, Becker C, Korff M. Targeted resequencing reveals genomic signatures of barley domestication. New Phytol. 2018;218:1247-1259. DOI: 10.1111/nph.15077
8.Mascher M, Schuenemann VJ, Davidovich U, Marom N, Himmelbach A, H€ubner S, Korol A, David M, Reiter E, Riehl S, Schreiber M, Vohr SH, Green RE, Dawson IK, Russell J, Kilian B, Muehlbauer GJ, Waugh R, Fahima T, Krause J, Weiss E, Stein N. Genomic analysis of 6,000-year-old cultivated grain illuminates the domestication history of barley. Nat Genet. 2016;48:1089-1093. DOI: 10.1038/ng.3611
9.Jayakodi M, Padmarasu S, Haberer G. et al. The barley pan-genome reveals the hidden legacy of mutation breeding. Nature. 2020;588:284-289. DOI: https://doi.org/10.1038/s41586-020-2947-8
10.Haas M, Schreiber M, Mascher M. Domestication and crop evolution of wheat and barley: Genes, genomics, and future directions J Integr Plant Biol. 2018;61:204-225. DOI: 10.1111/jipb.12737
11.Newman CW and Newman RK. A brief history of barley foods. Cereal Foods World. 2006;51:4-7. DOI: 10.1094/CFW-51-0004
12.Newton AC, Flavell AJ, George TS, Leat P, Mullholland B, Ramsay L, Revoredo-Giha C, Russell J, Steffenson BJ, et al. Crops that feed the world 4. Barley: a resilient crop? strengths and weaknesses in the context of food security. Food Secur. 2011;3:141-178. DOI: 10.1007/s12571-011-0126-3
13.Giraldo P, Benavente E, Manzano-Agugliaro F Gimenez E. Worldwide research trends on wheat and barley: a bibliometric comparative analysis. Agronomy. 2019;9:352. DOI: https://doi.org/10.3390/agronomy9070352
14.Baik BK and Ullrich SE. Barley for food: Characteristics, improvement, and renewed interest. J Cereal Sci. 2008;48:233-242. DOI: https://doi.org/10.1016/j.jcs.2008.02.002
15.Heuberger AL, Broeckling CD, Kirkpatrick KR, Prenni JE. Application of nontargeted metabolite profiling to discover novel markers of quality traits in an advanced population of malting barley. Plant Biotechnol J. 2014;12:147-160. DOI: 10.1111/pbi.12122
16.Herb D, Filichkin T, Fisk S, Helgerson L, Hayes P, Benson A, Thomas W. Malt modification and its effects on the contributions of barley genotype to beer flavor J Am Soc Brew Chem. 2017;75:354-362. DOI: https://doi.org/10.1094/ASBCJ-2017-4976-01
17.Harwood WA. An introduction to barley: the crop and the model. Methods Mol Biol. 2019;1900:1-5. DOI: 10.1007/978-1-4939-8944-7_1
18.Nikkhah A. Barley grain for ruminants: A global treasure or tragedy. J Anim Sci Biotechnol. 2012;3:22 http://www.jasbsci.com/content/3/1/22
19.Kim CH. Kang HK. Effects of fermented barley or wheat as feed supplement on growth performance, gut health and meat quality of broilers Europ Poult Sci. 2016;80. DOI: 10.1399/eps.2016.162
20.Nicoli MC, Anese M, Parpinel M. Influence of processing on the antioxidant properties of fruits and vegetables. Trends Food Sci and Tech. 1999;10:94-100. DOI: https://doi.org/10.1016/S0924-2244(99)00023-0
21.Zhu Y, Li T, Fu X, Abbasi AM, Zheng B, Liu RH. Phenolics content, antioxidant and antiproliferative activities of dehulled highland barley (Hordeum vulgare L.). J Funct Foods. 2015;19:439-450. DOI: 10.1016/j.jff.2015.09.053
22.Ge X, Jing L, Zhao K, Su C, Zhang B, Zhang Q, Han L, Yu X, Li W. The phenolic compounds profile, quantitative analysis and antioxidant activity of four naked barley grains with different color. Food Chem. 2021;335:127655. DOI: 10.1016/j.foodchem.2020.127655
23.Gangopadhyay N, Hossain MB, Rai DK, Brunton NP. A review of extraction and analysis of bioactives in oat and barley and scope for use of novel food processing technologies. Molecules. 2015;20:10884-10909. DOI: 10.3390/molecules200610884
24.Guo H, Lin S, Lu M,. Gong GDB, Wang L, Zhang Q, Wu DT. Characterization, in vitro binding properties, and inhibitory activity on pancreatic lipase of β-glucans from different Qingke (Tibetan hulless barley) cultivars. Int J Biol. 2018;120:2517-2522. DOI: 10.1016/j.ijbiomac.2018.09.023
25.Shen Y, Zhang H, Cheng L, Wang L, Qian H, Qi X. In vitro and in vivo antioxidant activity of polyphenols extracted from black highland barley. Food Chem. 2016;194:1003-1012. DOI: 10.1016/j.foodchem.2015.08.083
26.Izydorczyk, MS, McMillan T, Bazin S, Kletke J, Dushnicky L, Dexter J, Chepurna A, Rossnagel B. Milling of Canadian oats and barley for functional food ingredients: oat bran and barley fibre-rich fractions. Can J Plant Sci. 2014;94:573-586. DOI: https://doi.org/10.4141/cjps2013-229
27.Zhang G, Li C. Genetics and improvement of barley malt quality. Advanced topics in science and technology in China. Springer. 2009. DOI: 10.1007/978-3-642-01279-2_3
28.FAO-FAOSTAT. (Food and Agriculture Organization of the United Nations). Crops. 2020. Available from: http://www.fao.org/faostat/en/?#data/QC [Accessed: 2021-01-08]
29.Izydorczyck MS, Edney M. Barley: Grain-quality characteristics and management of quality requirements. Cereal Grains Elsevier Ltd. 2017
30.FAO Food outlook: biannual report on global food markets. 2016. ISSN 1560-8182, http://www.fao.org/3/ai5703e.pdf [Accessed: 2021-01-08]
31.International Grains Council. Available from: https://www.igc.int/en/markets/marketinfo-sd.aspx [Accessed: 2021-01-08]
32.Mathison GW. Effects of processing on the utilization of grain by cattle. Anim Feed Sci and Technol. 1996;58:113-125. DOI: https://doi.org/10.1016/0377-8401(95)00878-0
33.Dehghan-banadaky M, Corbett R, Oba M. Effects of barley grain processing on productivity of cattle. Anim Feed Sci and Technol. 2007;137:1-24. DOI: 10.1016/j.anifeedsci.2006.11.021
34.McAllister M and Meale S. Barley grain- feed industry guide. Alberta Barley. 2015;1:1-35. Available from: https://www.albertabarley.com/download-feedguide/ [Accessed: 2021-01-08]
35.Călinoiu LV, Vodnar DC. Whole Grains and Phenolic Acids: A Review on bioactivity, functionality, health benefits and bioavailability. Nutrients. 2018; 10:1615. DOI: 10.3390/nu10111615
36.Zheng GH, Rossnagel BG, Tyler TR, Bhatty RS. Distribution of β-glucan in the grain of hull-less barley. Cereal Chem. 2000;77:140-144. DOI: 10.1094/CCHEM.2000.77.2.140
37.Barley Malt Beer. Agribusiness Handbook. Food and Agriculture Organization of the United Nations and European Bank for Reconstruction and Development. 2009. Available from: http://www.eastagri.org/publications/detail.php?id=35 [Accessed: 2021-01-08]
38.Bettenhausen HM, Barr L, Broeckling CD, Chaparro JM, Holbrook C, Sedin D, Heuberger AL. Influence of malt source on beer chemistry, flavor, and flavor stability. Food Res Int. 2018;113:487-504. DOI: 10.1016/j.foodres.2018.07.024
39.Fox GP. Chemical composition in barley grains and malt quality. Genetics and improvement of barley malt quality. Advanced Topics in Science and Technology in China. Springer. 2010. DOI: 10.1007/978-3-642-01279-2_3
40.Izydorczyk MS and Dexter JE. Barley beta-glucans and arabinoxylans: Molecular structure, physicochemical properties, and uses in food products–A review. Food Res Int. 2008;41:850-868. DOI: https://doi.org/10.1016/j.foodres.2008.04.001
41.Park KH, Lee KY, Lee HG. Chemical composition and physicochemical properties of barley dietary fiber by chemical modification. Int J Biol Macromol. 2013;60:360-365. DOI: 10.1016/j.ijbiomac.2013.06.024
42.Young VR and Pellett PL Plant proteins in relation to human protein and amino acid nutrition. Am J Clin Nutr. 1994;59:1203S–1212S. DOI: 10.1093/ajcn/59.5.1203S
43.Lange M, Vincze E, Wieser H, Schjoerring JK, Holm PB. Suppression of C-hordein synthesis in barley by antisense constructs results in a more balanced amino acid composition. J Agric Food Chem. 2007;55:6074-6081. DOI: https://doi.org/10.1021/jf0709505
44.Mahalingam R. Shotgun proteomics of the barley seed proteome. BMC Genomics. 2017;18:44. DOI: 10.1186/s12864-016-3408-5
46.Ingvordsen CH, Gislum R, Jørgensen JR, Mikkelsen TN, Stockmarr A, Jørgensen RB. Grain protein concentration and harvestable protein under future climate conditions. A study of 108 spring barley accessions. J Exp Bot. 2016;67:2151-2158. DOI: 10.1093/jxb/erw033
47.Huang H, Gao X, Li Y, Tian P, Nima Y, Laba Z, Ci Z, Wei X, Qu J, Guan W, Liao W. Content analysis of vitamins, dietary fibers and amino acids in a wide collection of barley (Hordeum vulgare L.) from Tibet, China. Bioinformation. 2020;16:314-322. DOI: 10.6026/97320630016314
48.Rico D, Peñas E, García MDC, Martínez-Villaluenga C, Rai DK, Birsan RI, Frias J, Martín-Diana AB. Sprouted barley flour as a nutritious and functional ingredient. Foods. 2020;9:296. DOI: https://doi.org/10.3390/foods9030296
49.Martínez M, Motilva MJ, López de Las Hazas MC, Romero MP, Vaculova K, Ludwig IA. Phytochemical composition and β-glucan content of barley genotypes from two different geographic origins for human health food production. Food Chem. 2018;245:61-70. DOI: 10.1016/j.foodchem.2017.09.026
50.Abdel-Aal ESM, Choo TM, Dhillon S, Rabalski I. Free and bound phenolic acids and total phenolics in black, blue, and yellow barley and their contribution to free radical scavenging capacity. Cereal Chem. 2012;89:198-204. DOI: https://doi.org/10.1094/CCHEM-10-11-0116|
51.Holtekjølen AK, Kinitz C, Knutsen SH. Flavanol and bound phenolic acid contents in different barley varieties. J Agri Food Chem. 2006;54:2253-2260. DOI: https://doi.org/10.1021/jf052394p
52.Lempereur, I., Rouau, X. and Abecassis, J. Genetic and agronomic variation in arabinoxylan and ferulic acid contents of durum wheat (Triticum durum L.) grain and its milling fractions. J Cereal Sci. 1997;25:103-110. DOI: 0733-5210/97/020103+08 $25.00/0/jc960090
53.Chung KT, Wei CI, Johnson MG. Are tannins a double-edged sword in biology and health? Trends Food Sci. Technol. 1998;9:168-175. DOI: 10.1016/s0924-2244(98)00028-4
54.Brimson JM, Onlamoon N, Tencomnao T, Thitilertdecha P. Clerodendrum petasites S. Moore: The therapeutic potential of phytochemicals, hispidulin, vanillic acid, verbascoside, and apigenin. Biomed Pharmacother. 2019;118:109319. DOI: https://doi.org/10.1016/j.biopha.2019.109319
55.Bezerra-Filho CSM, Barboza JN, Souza MTS, Sabry P, Ismail NSM, de Sousa DP. Therapeutic potential of vanillin and its main metabolites to regulate the inflammatory response and oxidative stress. Mini Rev Med Chem. 2019;19:1681-1693. DOI: 10.2174/1389557519666190312164355
56.Srinivasulu C, Ramgopal M, Ramanjaneyulu G, Anuradha CM, Suresh Kumar C. Syringic acid (SA) - a review of its occurrence, biosynthesis, pharmacological and industrial importance. Biomed Pharmacother. 2018;108:547-557. DOI: 10.1016/j.biopha.2018.09.069
57.Chen C. Sinapic Acid and Its Derivatives as Medicine in Oxidative Stress-Induced Diseases and Aging. Oxid Med Cell Longev. 2016;3571614. DOI: 10.1155/2016/3571614
58.Srinivasan M, Sudheer AR, Menon VP. Ferulic acid: Therapeutic potential through its antioxidant property. J Clin Biochem Nutr. 2007;40:92-100. DOI: 10.3164/jcbn.40.92
59.Garrait G, Jarrige JF, Blanquet S, Beyssac E, Cardot JM, Alric M. Gastrointestinal absorption and urinary excretion of trans-cinnamic and p-coumaric acids in rats. J Agric Food Chem. 2006;54:2944-2950. DOI: 10.1021/jf053169a
60.Idehen E, Tang Y, Sang S. Bioactive phytochemicals in barley. J Food Drug Anal. 2017;25:148-161. DOI: 10.1016/j.jfda.2016.08.002
61.Abdel-Aal ESM, Young JC, Rabalski I. Anthocyanin composition in black, blue, pink, purple, and red cereal grains. J Agric Food Chem. 2006;54:4696-4704. DOI: 10.1021/jf0606609
62.Yang T, Duan CL, Zeng YW, Du J, Yang SM, Pu XY, Yang SC. HPLC analysis of flavonoids compounds of purple, normal barley grain. AMR. 2013;634:1486-1490
63.Dvorakova M, Moreira MM, Dostalek P, Skulilova Z, Guido LF, Barros AA. Characterization of monomeric and oligomeric flavan-3-ols from barley and malt by liquid chromatography–ultraviolet detection–electrospray ionization mass spectrometry. J Chromatogr A. 2008;1189:398-405. DOI: 10.1016/j.chroma.2007.10.080
64.Özcan MM, Aljuhaimi F, Uslu N. Effect of malt process steps on bioactive properties and fatty acid composition of barley, green malt and malt grains. J Food Sci Technol. 2018;55:226-232. DOI: 10.1007/s13197-017-2920-1
65.Tiwari U and Cummins E. Nutritional importance and effect of processing on tocols in cereals. Trends Food Sci Technol. 2009;20:511-520. DOI: 10.1016/j.tifs.2009.06.001
66.Bloedon LT, Balikai S, Chittams J, Cunnane SC, Berlin JA, Rader DJ, Szapary PO. Flaxseed and cardiovascular risk factors: results from a double blind, randomized, controlled clinical trial. J Am Coll Nutr. 2008;27:65-74. DOI: 10.1080/07315724.2008.10719676
67.Wang L, Newman RK, Newman CW, Jackson LL, Hofer PJ. Tocotrienol and fatty acid composition of barley oil and their effects on lipid metabolism. Plant Foods Hum Nutr. 1993;43:9-17. DOI: 10.1007/BF01088091
68.Ostlund Jr, RE, Racette SB, Okeke A, Stenson WF. Phytosterols that are naturally present in commercial corn oil significantly reduce cholesterol absorption in humans. Am J Clin Nutr. 2002;75:1000-1004. DOI: 10.1093/ajcn/75.6.1000
69.Williamson G. The role of polyphenols in modern nutrition. Nutr Bull. 2017;42:226-235. DOI: 10.1111/nbu.12278
70.Pool-Zobel B, Bub A, Schröder N, Rechkemmer G. Anthocyanins are potent antioxidants in model systems but do not reduce endogenous oxidative DNA damage in human colon cells. Eur J Nutr. 1999;38:227-234. DOI: 10.1007/s003940050065
71.Krga I and Milenkovic D. Anthocyanins: From sources and bioavailability to cardiovascular-health benefits and molecular mechanisms of action. J Agric Food Chem. 2019;67:1771-1783. DOI: 10.1021/acs.jafc.8b06737
72.Gangopadhyay N, Rai DK, Brunton NP, Gallagher E, Hossain MB. Antioxidant-guided isolation and mass spectrometric identification of the major polyphenols in barley (Hordeum vulgare) grain. Food Chem. 2016;210:212-220. DOI: 10.1016/j.foodchem.2016.04.098
73.Bravi E, Marconi O, Perretti G, Fantozzi P. Influence of barley variety and malting process on lipid content of malt. Food Chem. 2012;135:1112-1117. DOI: 10.1016/j.foodchem.2012.06.041
74.Chatterjee S, Bagchi D. Eating habits in combating disease: nutraceuticals and functional foods at the crossroads of immune health and inflammatory responses. Immunity and inflammation in health and disease. Academic Press. 2017. DOI: 10.1016/B978-0-12-805417-8.00032-9
75.Adaszyńska-Skwirzyńska M, Szczerbińska D. Use of essential oils in broiler chicken production - a review. Ann Anim Sci. 2017;17:317-335. DOI: 10.1515/aoas-2016-0046
76.Walde CM, Drotleff AM, Ternes W. Comparison of dietary tocotrienols from barley and palm oils in hen's egg yolk: transfer efficiency, influence of emulsification, and effect on egg cholesterol. J Sci Food Agric. 2014;94:810-818. DOI: 10.1002/jsfa.6484
77.Regmi PR, Sauer WC, Zijlstra RT. Prediction of in vivo apparent total tract energy digestibility of barley in grower pigs using an in vitro digestibility technique. J Anim Sci. 2008;86:2619-2626. DOI: 10.2527/jas.2008-1058
78.Bennett CD, Classen HL, Schwean K, Riddel C. Influence of whole barley and grit on live performance and health of turkey toms. Poultry Science. 2002;81:1850-1855. DOI: 10.1093/ps/81.12.1850
79.Manthey FA, Hareland G A, Huseby D. Soluble and insoluble dietary fibre content and composition in oat. Cereal Chem. 1999;76:417-420. DOI: 10.1094/CCHEM.1999.76.3.417|
80.Koo B, Bustamante-García D, Kim JW, Nyachoti CM. Health-promoting effects of Lactobacillus-fermented barley in weaned pigs challenged with Escherichia coli K88. Animal. 2020;14:39-49. DOI: 10.1017/S1751731119001939
81.Lampe JF, Bass TJ, Mabry JW. Comparison of grain sources for swine diets and their effect on meat and fat quality traits. J Anim Sci. 2006;84,1022-1029
82.Ramakrishna R, Sarkar D, Shetty K. Functional bioactives from barley for human health benefits. Functional foods and biotechnology. CRC Press. 2019. DOI: 10.1201/9781003003830-5
83.Behall KM, Scholfield DJ, Hallfrisch J. Diets containing barley significantly reduce lipids in mildly hypercholesterolemic men and women. Am J Clin Nutr. 2004;80:1185-1193 DOI: 10.1093/ajcn/80.5.1185
84.Fadel JG, Newman RK, Newman CW, Barnes AE. Hypocholesterolemic effects of β-glucans in different barley diets fed to broiler chicks. Nutr Rep Int. 1987;35:1049-1058
85.Newman RK, Lewis SE, Newman CW, Boik RJ, Ramage RT. Hypocholesterolemic effect of barley foods on healthy men. Nutrition Reports International. 1989;39:749-760
86.Naumann E, VaN Rees AB, Önning G, Öste R, Wydra M, Mensink RP. Beta-glucan incorporated into a fruit drink effectively lowers serum LDL-cholesterol concentrations. Am J Clin Nutr. 2006;83:601-605. DOI: 10.1093/ajcn.83.3.601
87.Wang Y, Harding SV, Thandapilly SJ, Tosh SM, Jones PJH, Nancy PA. Barley β-glucan reduces blood cholesterol levels via interrupting bile acid metabolism. Br J Nutr. 2017;118:822-829. DOI: 10.1017/S0007114517002835
88.Braaten JT, Wood PJ, Scott FW, Riedel KD, Poste LM, Collins MW. Oat gum lowers glucose and insulin after an oral glucose dose. Am J Clin Nutr. 1991;53:1425-1430. DOI: 10.1093/ajcn/53.6.1425
89.Cavallero A, Empilli S, Brighenti F, Stanco AM. High (1 → 3, 1 → 4)-β-glucan barley fractions in bread making and their effects on human glucemic response. J Cereal Sci. 2002;36:59-66DOI: 10.1006/jcrs.2002.0454
90.Wood PJ, Braaten JT, Scott FW, Riedel D, Poste LM. Comparisons of viscous properties of oat and guar gum and the effects of these and oat bran on glycemic index. J Agric Food Chem. 1990;38:753-757. DOI: 10.1021/jf00093a036
91.Ames N, Storsley J. Effects of barley on post prandial glycemic response. Diabesity. 2015;1:21-23. DOI: 10.15562/diabesity.2015.15
92.United States Food and Drug Administration. Health claims: Soluble dietary fiber from certain food and coronary heart disease. In: Code of Federal Regulations Title 21, Vol. 2. Washington DC. USA. 2006. Available from: http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=101.81 [Accessed: 2021-01-08]
93.European Food Safety Authority (EFSA). Scientific Opinion on the substantiation of health claims related to beta-glucans from oats and barley and maintenance of normal blood LDL-cholesterol concentrations (ID 1236, 1299), increase in satiety leading to a reduction in energy intake (ID 851, 852), reduction of post-prandial glycaemic responses (ID 821, 824), and "digestive function" (ID 850) pursuant to Article 13(1) of Regulation (EC) No. 1924/2006. EFSA J. 2011;9:2207
94.Health Canada. Summary of health Canada's assessment of a health claim about barley products and blood cholesterol lowering. 2012. Available from: https://www.canada.ca/en/health-canada/services/food-nutrition/food-labelling/health-claims/assessments/assessmenthealth-claim-about-barley-products-blood-cholesterol-lowering.html [Accessed: 2021-01-08]
95.Food Standards Australia New Zealand (FSANZ). Available from: http://www.foodstandards.gov.au/consumer/labelling/nutrition/Pages/Consultation-about-beta-glucan-and-blood-cholesterol-health-claims.aspx [Accessed: 2021-01-08]
96.Fogarasi AL, Kun S, Tankó G, Stefanovits-Bányai E, Hegyesné-Vecseri B. A comparative assessment of antioxidant properties, total phenolic content of einkorn, wheat, barley and their malts. Food Chem. 2015;167:1-6. DOI: 10.1016/j.foodchem.2014.06.084
97.Badea A, Carter A, Legge WG, Sallow K, Johnston SP, Izydorczyk MS. Tocols and oil content in whole grain, brewer's spent grain, and pearling fractions of malting, feed, and food barley genotypes. Cereal Chem. 2018;95:779-782. DOI: 10.1002/cche.10093|
98.Qureshi AA, Burger WC, Peterson DM, Elson CE. The structure of an inhibitor of cholesterol biosynthesis isolated from barley. J Biol Chem. 1986;261:10544-10550
99.Qureshi AA, Qureshi N, Wright JJK, Shen Z, Kramer G, Gapor A, Chong YH, Dewitt G, Ong ASH, Peterson DM, Bradlow BA. Lowering serum cholesterol in hypercholesterolemic humans by tocotrienols (palmvitee). Am J Clin Nutr. 1991;53:1021-1026. DOI: 10.1093/ajcn/53.4.1021S
100.Jialal I, and Devaraj S. Scientific evidence to support a vitamin E and heart disease health claim: Research needs. J Nutr. 2005;135:348-353. DOI: 10.1093/jn/135.2.348
101.Yang X-J, Dang B, Fan M-T. Free and bound phenolic compound content and antioxidant activity of different cultivated blue highland barley varieties from the Qinghai-Tibet Plateau. Molecules. 2018;23:879. DOI: 10.3390/molecules23040879
102.Brenelli de Paiva L, Goldbeck R, Dantas dos Santos W, Squina FM. Ferulic acid and derivatives: Molecules with potential application in the pharmaceutical field. Braz J Pharm Sci. 2013;49:395-411. DOI: 10.1590/S1984-82502013000300002
103.Kumar A, Mosa KA, Ji L, Kage U, Dhokane D, Karre S, Madalageri D, Pathania N. Metabolomics-assisted biotechnological interventions for developing plant-based functional foods and nutraceuticals. Crit Rev Food Sci Nutr. 2018;58:1791-1807. DOI: 10.1080/10408398.2017.1285752
104.Zhang JX, Bergman F, Hallmans G, Johansson G, Lundin E, Stenling R, Theander OL, Westerlund ER. The influence of barley fibre on bile composition, gallstone formation, serum cholesterol and intestinal morphology in hamsters. APMIS. 1990;98:568-574. DOI: 10.1111/j.1699-0463.1990.tb01072
105.Finn OJ. Cancer immunology. N Engl J Med. 2008;358:2704-2715. DOI: 10.1056/NEJMra072739
106.Bays H, Frestedt JL, Bell M, Williams C, Kolberg L, Schmelzer W, Anderson JW. Reduced viscosity barley β-Glucan versus placebo: a randomized controlled trial of the effects on insulin sensitivity for individuals at risk for diabetes mellitus. Nutr Metab (Lond). 2011;8:1
107.Shimizu C, Wakita Y, Kihara M, Kobayashi N, Tsuchiya Y, Nabeshima T. Association of lifelong intake of barley diet with healthy aging: changes in physical and cognitive functions and intestinal microbiome in senescence-accelerated mouse-prone 8 (SAMP8). Nutrients. 2019;11:1770. DOI: 10.3390/nu11081770
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