The aim of this study was to define effects of milling and germination on total phenolics content and antioxidant activity of barley (naked cv. Rastik and covered cv. Start) and oat (naked cv. Akt and covered cv. Kasztan) grain. The level of phenolics in barley grain of naked and covered cultivars was similar (1.3 mg catechin/g d.m.). In contrast, the level of these compounds differed between oat cultivars (cv. Akt-1.86 and cv. Kasztan-1.08% mg catechin/g d.m.). The highest antioxidant activity was demonstrated for naked oat (cv. Akt-56.6%). Barley flour, as compared with oat flour, showed higher phenolics content and had higher antioxidant activity. Equally, the level of phenolics in barley bran was higher than that in oat bran. The highest antioxidant activity was observed for oat bran obtained from cv. Akt (61.63%); the antioxidative potential of the remaining forms of barley and oat was comparable. The highest phenolics content was determined in extracts of germinated barley and oat grain. Higher antioxidant activity was observed for the naked forms of barley and oat (cv. Rastik.-.63.81 and cv. Akt.- 67.15%) whereas the covered forms showed lower values of this activity (cv. Start.-.52.49 and cv. Kasztan – 58.32%). For the total of studied material, the correlation coefficient between total phenolics content and antioxidant activity reached the value r = 0.596. For the four studied forms, the above coefficient was: cv. Rastik – r = 0.720; cv. Start – r = 0.849; cv. Akt – r = 0.921; cv. Kasztan – r = 0.772. In view of large differences in antioxidant activity between individual phenolic compounds, further studies on antioxidant acivity of barley and oat grain should involve identification of individal phenolics in extracts derived from these cereals.
barley, oat, covered and naked cultivars, antioxidant activity