BLACK WHEAT BRAN AS A PROMISING SOURCE OF FOOD FIBRES WITH AN EXPANDED SPECTRUM OF FUNCTIONALITIES

Abstract

Modern requirements of nutritiology determine the enrichment of a person’s daily diet with food fibres. Dietary supplements and cereal-based ingredients are widely used to achieve this goal. Wheat as a food crop traditionally occupies a leading position in food production. Currently, new varieties of wheat with colored grains are being given increasing attention as a source of high-activity phytochemical compounds, which can initiate a positive synergistic physiological effect in the complex. The black-grain wheat of the domestic variety "Chornobrova" belongs to the functional species among the new valuable colored varieties of wheat. It contains an increased amount of biologically active components concentrated in the husk and germ of the grain. At grain processing plants by-products are formed in the production of flour and cereals, among which the hard shells of grain release in the form of bran, that have a rich source of dietary fibres. The paper describes the breaking bran and grinding bran of black-grained wheat "Chornobrova". They contain up to 78.0% of polysaccharides, among which hemicelluloses and cellulose predominate. Both types of black wheat bran are protein-rich (13.0-15.3%), and the crude fat content does not exceed 2.1%. The non-hydrolyzed residue, represented primarily by lignin, reaches 3.8%. Bran is rich in phenolic compounds – powerful antioxidants with the mass fraction 310.0 mg/100 g. Both types of bran have a water retention and sorption capacity towards toxicants (phenol, Pb2+), cholic acid, methylene blue. As a result of acid treatment of bran, dietary fibre concentrates were obtained, in which non-starch polysaccharides predominate. They are characterized by modified physicochemical properties, namely improved water holding capacity, sorption activity against Pb2+, not inferior to bran in terms of the ability to bind cholic acids and methylene blue. "Chornobrova" wheat bran and dietary fibre concentrates are highly active enterosorbents with antioxidant activity, which can be considered as dietary supplements and food ingredients that should be included in recipes in the development of new functional foods.

Keywords

• black wheat
• bran
• dietary fibre
• enterosorbents
• phenolic antioxidants