THE EFFECT OF HEAT TREATMENT OF PIGMENTED BARLEY AND WHEAT GRAINS ON ITS ANTIOXIDANT ACTIVITY

The purpose of this study is to analyze the effect of heat treatment of pigmented grain of near isogenic wheat and barley lines on the content of phenolic compounds and the antioxidant activity of the Khakass national product talgan, in the manufacture of which the grain is roasted and ground. The work was carried out using near isogenic wheat lines iP and barley PLP, BA, BLP, which differ from the control unpigmented lines iP7D and Bowman, respectively, by the presence of anthocyanin or melanin pigments in the grain. It was shown that pigmented wheat and barley grains contained 13–63% more phenolic compounds compared to the grain of the control lines. At the same time, the BLP barley line, which accumulates melanins in grain, was characterized by the highest content of phenolic compounds (3.04 mg/g), and the iP7D wheat line was characterized by the lowest (1.58 mg/g). A strong positive correlation was found between the content of free phenolic compounds and the antioxidant activity of methanol extracts of grain (rs = 0.879, p<0.05). The talgan prepared from the tested grain showed an increase in the content of phenolic compounds by 8–43% compared to the initial grain. At the same time, pigmented grains were characterized by a higher content of phenolic compounds (wheat: 2.55 mg/g; barley: 2.55–3.48 mg/g) compared with grains of control lines (wheat: 2.03 mg/g; barley: 2.38 mg/g). The value of the antioxidant activity of talgan extracts was either significantly higher (Bowman, iP7D, iP) or tended to increase (PLP, BA, BLP) compared with unprocessed grain, while there was a strong positive correlation between the content of free phenolic compounds and the antioxidant activity of talgan extracts (rs = 0.896, p<0.05). Thus, the results demonstrated that pigmented wheat and barley grains are promising raw materials for the production of a functional healthy food product, the national Khakass talgan.