Human health benefits from buckwheat nutrients

Abstract

Buckwheat contains a variety of nutrients in its grains. The main compounds are proteins, rutin, polysacchardes, dietary fibre, lipids, polyphenols and micronutrients (minerals and vitamins). The total content of these components depends on different factors, such as the species and the environment. The amino acid composition of buckwheat proteins is well balanced and of a high biological value, although the protein digestibility is relatively low. Buckwheat grains are an important source of microelements, such as: Zn, Cu, Mn, Se, and macro elements: K, Na, Ca, and Mg. With 80% unsaturated fatty acids more than 40% are constituted by polyunsaturated fatty acid (PUFA). The significant contents of rutin, catechins and other polyphenols as well as their potential antioxidant activity are also of significance to the dietary value. Moreover, buckwheat grains are a rich source of TDF (total dietary fibre), soluble dietary fibre (SDF), and are applied in the prevention of obesity and diabetes. An increasing incidence of allergy manifestations or symptoms is observed in people who consume buckwheat-containing food products often and in high quantities. The main reason for such immunological disorders is low molecular weight proteins, particularly those with molecular weights of 15, 22, or 26 kDa. These are concentrated in the peripheral parts of endosperm and embryo, hence the highest quantity of B vitamins is found in the bran. Tartary buckwheat bran contains about 6% of daily therapeutic doses of pyridoxine, effective in the reduction of blood plasma homocysteine levels. Protein extracts are more efficient in lowering the blood cholesterol level, particularly that of LDL and VLDL. Buckwheat proteins products (BWP) are acknowledged as preventive nutrients. They use advisable modifications, e.g. enzymatic modifications that consist in enzymatic separation of allergenic constituents or controlled fermentations performed by yeast or mould strains. Vitamins are a group of organic compounds that are essential in very small amounts for the normal functioning of the human body. They vary widely in their chemical and physiological functions and are broadly distributed in natural food sources. Buckwheat grains contain higher levels of vitamin B1 (thiamine), B2 (riboflavin), E (tocopherol) and B3 (niacin and niacinamide) compared with most cereals. Generally, tartary buckwheat has more vitamin B1, B2 and B3, but less vitamin E than common buckwheat. In general, tartary buck wheat has higher levels of vitamin B than common buck-wheat. Thiamine-binding proteins can improve the stability of thiamine during storage and improve the bioavailability of thiamine. Levels of vitamin C and the sum of vitamin B1and B6 can be increased by germinating buckwheat. The level of vitamin C can be increased by up to 0·25mg/g in buckwheat sprouts. Wheat, barley, oat, rye and buckwheat groats exhibit the same maximum level of tocopherols, with γ-tocopherol being the main one.