Evaluation of the antioxidant activity of lupin seed flour and derivatives(Lupinus albus ssp. Graecus)

In order to investigate natural sources of nutritive and non-nutritive anti oxidants, the methanol extracts of lupin (Lupinus albus spp. Graecus) flour (with and without alkaloids) and lupin protein isolate were first examined for their antioxidant activity. The antioxidant activity of these extracts was determined by a rapid spectrophotometric method based on the coupled o xidation of beta-carotene and linoleic acid and also by carrying out stabil ity tests at 63 degrees C with cottonseed oil. The results showed that the methanol extracts of lupin exhibit a marked antioxidant activity, higher th an that of soya flour extracts. In a second step, an attempt was made to de tect some of the components that may contribute to the overall antioxidant activity such as phenols, flavonoids, amino acids and peptides by using thi n-layer chromatography. Finally, the pronounced antioxidant activity was co rrelated to the presence of total phenolics and phospholipids at high conce ntrations in the lupin extracts. (C) 1999 Elsevier Science Ltd. All rights reserved.