Effect of enzymatically interesterified oil-based plastic fats on physicochemical and structural properties of pre-cooked gluten during freeze-thaw cycling

To alleviate the quality deterioration of frozen pre-cooked flour products, this study examined the effect of enzymatically interesterified rapeseed oil-based plastic fats (EIPF) on the physicochemical and structural properties of pre-cooked gluten (PCG) during freeze-thaw (FT) cycling. Incorporation of 1 % EIPF alleviated the ice crystal-induced damage to the gluten network, therefore mitigating the physicochemical properties changes of PCG during FT cycles, including degraded textural properties, thermal destabilization, diminished particle size, and variation in hydration-oil duality. EIPF mitigated the destructive depolymerization of PCG, and inhibited the reduction in α-helix and β-turn (15.47 % and 4.01 %) during FT cycles. EIPF interacted with PCG by ionic bond and hydrogen bond, meanwhile reducing the hydrophobic interaction. EIPF reduced SH content (35.49 %) and increased initial S-S bond (8 %), revealing the promoted cross-linking of gluten. Additionally, EIPF stabilized both covalent and non-covalent interaction changes during FT cycling. In conclusion, this study provides theoretical support for improving the quality of PCG and utilizing EIPF in frozen flour products.