Antioxidant properties of lupin seed products

Antioxidant properties of lupin flours and hulls were examined. Chemical composition (protein, fat, fatty acids, tocopherols and tannin contents) was determined and radiation effects were estimated (1, 5 and 10 kGy). Antioxidant properties of the ethanol lupin extracts were examined using the Rancimat and Oxidograph tests. Alpha-, gamma- and delta-tocopherols were found in the lupin oil. Lupin tannins contents in the flours were a few times higher than in the hulls. Antioxidant activity was found both in the flours and in the hulls. Correlation between the antioxidant properties and the tocopherol and tannin contents (the natural lupin antioxidants) was not found. Increasing doses of irradiation lowered antioxidant effects of lupin extracts; however, the antioxidant activities of some samples were higher. The observed negative changes in the tocopherols contents were effects of the irradiation dose as well as storage time.