Effect of germination and fermentation on the antioxidant vitamin content and antioxidant capacity of Lupinus albus L. var. Multolupa

The present work studies the antioxidant capacity as well as the vitamin C and E contents of raw, fermented and germinated seeds of Lupinus albus L. var. Multolupa. Vitamin C was quantified by micellar electrokinetic capillary electrophoresis and vitamin E isomers by high performance liquid chromatography. The antioxidant capacity was determined by spectrophotometry and expressed as trolox equivalent antioxidant capacity (TEAC) and by liposome methods using phospholipids bilayers. Germination, in general, brought about an increase in the content of α-tocopherol, a decrease in the content of γ-tocopherol and did not affect the content of δ-tocopherol, which resulted in an increment in the vitamin E activity. Vitamin C increased sharply but gradually after germination. Fermentation caused a drastic reduction in the antioxidant vitamin content, vitamin C was not detected and tocopherol isomers decreased significantly. Germination processes caused a significant increase in antioxidant capacity (TEAC) of both hydrophilic and lipophilic extracts and fermentation produced slight changes or total reduction in TEAC, depending on process conditions. The peroxidation of egg yolk phosphatidyl-choline (PC) was inhibited by all lupin extracts in comparison with control assay. Germination was selected as a good treatment to increase antioxidant capacity and vitamin C and E contents.