Aging, free radicals, and antioxidants in wheat seeds

Free radical oxidative attack is considered a major cause of disruption and deteriorative changes observed in aged seeds. Antioxidant defense mechanis ms may remove potentially damaging molecular species, and carotenoids may a ct as radical scavengers. The content of lutein, the major carotenoid in wh eat seeds, was determined in the flours. It showed a rapid decrease during seed aging. In addition, the content of free radicals in glutens made from flours of wheat seeds after long-term storage was studied. The concentratio n of radicals appeared to be age dependent, because the highest content of radicals was detected between 13 and 15 years of aging over 36 years of sto rage. Specific spin labeling of the sulfhydryl groups of gluten proteins en abled comparative EPR studies of the rigidity of the protein chains. A prog ressive stiffening of polymeric gluten with seed storage was found.