Time-dependent dynamics of starch structure, functionality and quality in rice noodles during inoculated fermentation

Inoculated fermentation improves rice noodle (RN) quality, but the underlying mechanisms of starch restructuring and their functional consequences remain unclear. This study monitored time-resolved changes in starch structure, functional properties, and RN cooking/textural performance. A 6 h fermentation produced the lowest cooking loss and the highest noodle hardness and springiness. At this optimum, coincident with α-amylase-mediated remodeling, B1-chain content, short-range order (R_1047/1022), relative crystallinity, double-helix content, and mass fractal dimension increased by 5.81%, 16.67%, 28.20%, 5.84%, and 4.88%, respectively. Concomitantly, peak/trough viscosity and breakdown were minimized, whereas gelatinization enthalpy (ΔH) and setback peaked. Spearman correlations (p < 0.01) confirmed that ordered starch structures, particularly B1 chains, were strongly associated with pasting behavior and RN quality. Mechanistically, α-amylase activity enriched B1 chains, enhanced short-range order and crystallinity, and reinforced the gel network, reducing breakdown and cooking loss. These findings highlight the importance of capturing starch dynamics and provide mechanistic insight and actionable guidance for precise fermentation control to achieve improved RN quality.