Study of gamma irradiation effects on the physico-chemical properties of wheat flour (Triticum aestivum, L.)

The present study deals with the effect of gamma irradiation (0, 0.25, 0.5, 1, 5, and 10 kGy) on the physicochemical properties of wheat flour. The physico-chemical properties of control and irradiated wheat flours are analyzed by the standard methods. After irradiation, no significant (p <= 0.05) changes are observed in the properties of wheat flour such as water absorption capacity, water absorption index, swelling property, loose bulk density, packed bulk density, total carbohydrate content, total antioxidant capacity, and lipid and protein profile. The solubility and foaming capacity remain unaffected up to 1 kGy, but significant (p <= 0.05) difference is seen at 5 and 10 kGy. The control as well as irradiated wheat flour show A-type pattern in the X-ray diffraction analysis with increase in percent crystallinity. The scanning electron microscope micrographs show round and oval wheat flour granules in the control, but irregular shaped granules in the irradiated wheat flour (5 and 10 kGy), which is associated with the protein network. The structural analysis by Fourier Transform Infrared Spectroscopy confirms no effect of gamma irradiation on the carbohydrate and water absorption capacity. Unaltered carbohydrate structure is confirmed by no changes in the O-H stretch, C-H stretch, C=O stretch, and pyranoid and furanoid ring vibrations at all irradiation doses. Most of the properties of the wheat flour irradiated at 1 kGy are under significance level (p <= 0.05) with minimum surface cracks on the irradiated wheat flour granules of lower dose indicating that this irradiation dose can be recommended for use in the preparation of bakery products to improve its quality and taste. The irradiation of wheat flour at 1 kGy can be used for complementary foods as it shows good physical attributes.