Oats are a very nutritious food with many health benefits. Long consumed in the form of flakes, oats become an asset thanks to its virtues.
[ Read more: Proven health benefits of oats ]
Starch constitutes about 60% of the oat grain. It is mainly a constituent of the endosperm. There is a considerable difference between the physicochemical properties of oat starch and other cereal starches. Differences in physicochemical properties are also observed between different oat cultivars. Oat starch offers atypical properties such as small granule size, well developed granule surface and high lipid content. Hoover and Vasanthan studied the characteristics of oat starches in light and their differences with other cereal starches. They reported that oat starches had a higher swelling factor, branched starch leaching and branched amylose, higher viscosity and shrinkage, low gel stiffness, increased susceptibility to hydrolysis of acid, greater resistance to α-amylase and a g reat thaw stability free..
Oats are considered as a potential source of low cost protein with good nutritional value. Oats have a unique protein composition with high protein content of 11-15%. Oat protein not only differs in the structural properties but also differs in the distribution of the fraction of protein in comparison with other cereal grains. In wheat and some other cereals, the protein is insoluble in saline solutions, whereas in oats, a large proportion of globulins soluble in salt water also belong to the endosperm reserve proteins.
Scientific research indicates that oats contain 78% alkali soluble protein fraction, 11% soluble in alcohol and 2.9% in salt, 4% residual protein and non-protein nitrogen (NPN).
Dietary fiber is an essential part of human nutrition. Oat-β-glucans are components of dietary fiber. Since β-glucan is a plant polysaccharide resistant to digestion and absorption in the small intestine, it also reduces blood cholesterol and glucose. Research has suggested that dietary fiber regulates the rate of digestion and nutrient uptake and serves as a substrate for the gut microflora and promotes laxation.
Starch is not considered part of dietary fiber because it is hydrolysed by enzymes and is absorbed into the small intestine. Whole oats contain a significant amount of dietary fiber, especially water-soluble (1 → 3) (1 → 4) β-glucan. The β-glucan content in oats ranges from 2.3 to 8.5 / 100 g. The Food and Drug Administration (FDA) has accepted a health claim stating that a daily intake of 3 g soluble β-glucan from oats can reduce the risk of coronary heart disease. Dietary fiber, particularly oat β-glucan, has potential anticancer properties as it reduces the compounds responsible for colon cancer, cholesterol levels and blood pressure. The recommended dose of β-glucan for a single food is 0.75 g / serving.
Oats are a good source of lipids. It contains many more lipids than other cereals, which are excellent sources of energy and unsaturated fatty acids. The majority of oat lipids are found in the endosperm. The fat content of oats varies from 5.0 to 9.0% of the total fat content. The lipid content in an intact oat core stored for 1 year at room temperature has been shown to be stable due to protection against endogenous antioxidants such as tocopherols, L-ascorbic acid, thiols, acids phenolic amines and other phenolic compounds.
Lipids and other lipid-related compounds in oats play an important role in the functionality of oat products. The high fat content of oats provides benefits when used for animal feed as it provides high energy and a good fatty acid composition. But when used as human food, this high lipid content provides fewer virtues, while causing various processing problems, such as poor flavor and excessive browning for grilled products. With lipids, oats contain a considerable amount of lipases, which are able to act under conditions of low humidity. If not controlled, these lipases cause rancidity and short shelf life of processed oat products.
Oats have been shown to offer a wide range benefits to human health, such as the reduction of diabetes symptoms and obesity. The main component of oats responsible for these health benefits is considered to be the β-glucan, but the phenolic compounds of oats and other antioxidant compounds also provide health benefits. Oats have an antioxidant capacity mainly due to the presence of tocopherols, tocotrienols, phytic acid, flavanoids and non-flavonoid phenolic compounds such as AVA.
Antioxidants such as vitamin E are known to protect the body against free radicals and play an important role in the prevention of diseases such as cancer, arthritis, atherosclerosis and cataracts. Oat germ has high levels of tocopherols (isomers a and c), while tocotrienols are mainly concentrated in the endosperm but are absent in the germ. The primary tocol of oats is α-tocotrienol, but a small amount of tocopherols and their β counterparts are also present. Total tocols ranged from 19 to 30.3 mg / kg. On total tocols, α-tocotrienol and α-tocopherols together account for 86 to 91%. The tocols have been stable in the unprocessed groats for more than 7 months of storage at room temperature, while the treatment of oats leads to degradation of these compounds in 1 to 2 months.
Oats are a good source of phenolic compounds. These phenolic compounds can contribute to the functional and nutritional properties of the grain. Cereals are phenolic compounds mainly derived from hydroxybenzoic and hydroxycinnamic acids. Previous studies have shown that phenolic acids found in oats have antioxidant properties both in vitro and in vivo. The main phenolic acids of oats are ferulic acid, p-coumaric acid, caffeine, vanillic acid, hydroxybenzoic acid and their derivatives. Traditionally, polyphenols are considered powerful antioxidants. Recent studies show that polyphenols can have much greater effects in vivo, such as improving endothelial function, cell signaling and anti-inflammatory properties. Oat hulls do not have much use in food, but they contain a significant amount of soluble ferulic acid, an antioxidant avenanthramide and also several other phenolic acids. The total free phenolic acid esters in oats are low at about 8.7 mg / kg, whereas the soluble phenolic acid esters are 20.6 mg / kg and the insoluble phenolic acids are about 57.7 mg / kg.
Oats are known for a unique group of antioxidants among cereals known as avenanthramide (AVA). There are abundant AVAs in oats, namely 2c, 2p and 2f, number 2 indicates 5 hydroxyanthranilic acid and letter c, p and f indicates the type of hydroxylcinnamic acids as p-caumaric, caffeic and ferulic acids, respectively. AVA has antioxidant activity 10 to 30 times higher than other phenolic antioxidants such as vanillin and caffeic acid. Preliminary studies have indicated that AVAs may possess anti-inflammatory and anti-atherogenic properties since they inhibit monocyte adhesion to human aortic endothelial cells and are presumed to inhibit the release of pro-inflammatory macrophage compounds. They are also involved in the control of blood pressure because they produce nitric oxide that dilates the blood vessels.
Oats have been used for centuries for its health, hair and skin benefits. These virtues are particularly due to its nutritional composition rich in vitamin, protein, starch and other compounds beneficial for the health in general.
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