Antioxidants, free radicals, storage proteins, and proteolytic activities in wheat (Triticum durum) seeds during accelerated aging

Accelerated aging was performed by incubation of wheat seeds at 40 °C and 100% relative humidity for 3, 4, 6, 10, and 14 days. The effects of the treatment on seed germinability and on several biochemical characteristics of flour (carotenoids, free radical and protein contents, and proteolytic activity) and gluten (free radical content and flexibility) were evaluated. A decrease of germinability was found during aging, the germination being completely inhibited after 14 days. The lutein content decreased gradually, without going to zero, while that of free radicals increased. A reduction of soluble proteins and a degradation of glutenins and gliadins were observed, associated with a substantial increase of protease activity and a decrease in gluten flexibility. The results were discussed in reference to those previously obtained by natural aging of wheat seeds of the same species and cultivar.