The effects of gamma irradiation treatment on starch structure and properties: a review
Chen Zhiguang, Rui Zhou, Qi Yang, Zhong Haixia
Abstract
Summary Gamma irradiation is a new starch processing and modification method. In this paper, the effects of gamma irradiation on starch structure and properties were summarised and discussed. In terms of starch structure, gamma irradiation destroys glycosidic bonds and significantly reduces the average molecular weight of starch, which may be the fundamental reason for the change in starch properties after irradiation. In addition, irradiation has no effects on crystal type but decreases the crystallinity of starch. Meanwhile, gamma irradiation can increase the specific surface area of starch granules but have no significant effects on the granular morphologies, indicating the damage to starch granules caused by irradiation proceeds from inside the granules. In terms of starch properties, gamma irradiation treatment decreases the viscosity, setback, breakdown, To, Tp, Tc, the enthalpy of crystalline melting, storage modulus, loss modulus, consistency coefficient and swelling ability of starches. In addition, gamma irradiation increases the b value, water absorption capacity, oil absorption capacity and solubility of starches. However, the results of the effects of irradiation on starch digestive, retrogradation and texture properties are not consistent in different studies. It may provide a reference for the application of irradiation in starch processing and modification.