How does the degree of phosphorylation substitution affect the protective effect of long-chain inulin on the quality deterioration of frozen dough?

This study compared the effects of phosphorylated modified long-chain inulin (PF) with low (PF1), medium (PF3), and high (PF6) degrees of substitution on the rheological, thermal, gluten network depolymerization characteristics, and microstructure of unfrozen and frozen dough. The results showed that PF increased G', G", Tp, and ΔH of unfrozen and frozen dough. Gluten protein analysis revealed that PF significantly increased the SS and α-helix content in gluten, with 3 %FPF3 showing an 11.35 μmol/g and 8.97 % increase compared to the control. Specifically, 3 %FPF1 increased the ΔH of gluten from 22.01 J/g to 37.26 J/g. SEM that PF improved the microstructure of the frozen dough by enhancing the continuity of the gluten network and promoting a more uniform distribution of air pockets. As the degree of phosphate substitution increased, the stability of the gluten network improved progressively. Overall, PF effectively delayed the damage caused by ice crystals to the stability of gluten proteins, leading to a significant improvement in the quality of the frozen dough.