Nutritional value and functional properties of flaxseed
AbstractThe nutritional value and functional properties of flaxseed Linum Usitatissimum L. are analyzed. There are three groups of compounds in the flaxseeds, characterized by specific biological activity and functional properties: PUFA ω-3 family, soluble dietary fiber in the form of mucus, and lignans, which have phytoestrogen properties. Data on the chemical composition of flaxseed, obtained from various sources, are characterized by high variability. The flaxseeds contain 35–45% oil, which contains 9–10% of saturated fatty acids (palmitic and stearic), about 20% monounsaturated fatty acids (mainly oleic acid), and more than 70% α-linolenic fatty acids acid. The protein content in seeds of flax varies from 20–30%. Proteins of flaxseeds are limited by lysine, but are characterized by a high coefficient of digestibility (89,6%) and biological value (77,4%). The content of dietary fiber reaches 28% by weight of whole seed, with the ratio of soluble and insoluble fractions from 20:80 until 40:60. According to the content of B-group vitamins and some minerals flaxseeds are close to the crops. Vitamin E in the flaxseeds is mainly in the form of γ-tocopherol (9,2 mg/100 g of seeds). Flaxseed is the richest in the vegetable world source of lignans (up to 0,7–1,5% of dry weight of seed), among which prevails secoisolariciresinol diglucoside. The chemical composition of flaxseed has identified areas in the study of preventive and functional properties. PUFA ω-3 family, dietary fibers and phytoestrogen lignans determine hypolipidemic and antiatherogenic actions of flaxseed. Flax seeds under the conditions of storage and processing technologies are harmless food product. Consumption of 50 g/day of flaxseed showed no adverse effects in humans.
Keywords:flaxseed, nutritional value, biological activity, functional properties