Abstract:Frozen flour products have been rapidly developed in the food industry, while some key scientific issues on the effects of the frozen storage process on the quality of flour products remain unclear. In this study, the effects of frozen storage (-18 ℃) on the molecular chain configuration, root mean square radius of gyration (Rg), and molecular weight of hydrated gluten were studied by small-angle X-ray scattering (SAXS). The results showed that before frozen storage, gluten molecules had a relatively loose chain structure in a 500 mM acetic acid solution, possessed a mass fractal structure (mass fractal dimension (Dm): 2.05), and a network structure. With elongated storage time, Dm value tended to decrease, indicating a gradually loose chain structure of gluten protein polymers. The Rg value and average molecular weight of gluten also tended to decrease with increasing frozen storage time and the change of Rg was positively correlated with that of Dm. These results demonstrated that depolymerization occurred during the frozen storage process due to the ice recrystallization, resulting in breaks in gluten molecule chains and a loose network structure.
