Effect of ultraviolet irradiation on immunoreactivity and other protein characteristics of wheat gliadin in flour and flatbread

Abstract

Pulsed light (PL) was investigated for reducing the immunoreactivity of gliadin of wheat flour, however, the obstacle with using PL light was that the food temperature was highly increased with a short treatment time. Therefore, ultraviolet (UV) irradiation was used to study its effects on immunoreactivity of gliadin, free sulfhydryl groups, gluten, and molecular weight of wheat proteins in wheat flour and flatbread samples. Also, the effect of heat treatment combined with UV light treatment on some protein features were studied. The immunoreactivity of gliadin was highly reduced, 60%, of flour treated with only UV, while the reduction was not obvious for flour treated with infrared light along with UV light and for flatbread samples. The free sulfhydryl groups were 3030, 3878, 4372, and 4784 µmol.g-1 after zero, 30, 60, and 120 min of UV light respectively. While the free sulfhydryl groups were reduced for flatbread samples treated by UV light. SDS-PAGE results showed that there was a clear reduction of the gliadin bands of flour treated with UV light compared to other treatments. In conclusion, thermal treatment along with or before UV light treatment reduced the effect of UV light on the immunoreactivity of wheat gliadin.