Effects of gamma-irradiation on composition of wheat lipids and purothionines

Abstract

The effects of gamma-irradiation on chemical composition of wheat lipids and on the changes in chemical properties of lipoprotein complex, were studied. No appreciable changes in total lipids in wheat, irradiated up to 1 Mrad, were observed. However, a significant increase in free lipids with concomitant decrease in bound lipids was observed. Separation of nonpolar and polar lipids into microconstituents did not show significant variations. Purothionines, extracted from lipid fractions of wheat flour exhibited several protein bands on electrophoretic separation; most of them disappeared at high dose level (1 Mrad). This may result in the disruption of lipid-purothionine complex. When bread dough was allowed to rest for 2 hr, aggregation of low molecular weight protein entities took place; this could strengthen the structure of lipoprotein complex during resting and baking.