Enhancing the Quality and Freezing Stability of Quick‐Frozen Sweet Dumplings via Oat β‐Glucan: Insights From Water State, Crystallization Behavior, and Multiscale Structure

ABSTRACT

In this study, oat β‐glucan (OβG) was added to glutinous rice flour at concentrations of 0.8%–4.0% (w/w) to investigate its effects on the quality, water distribution, freezing behavior, starch structure, and in vitro digestibility of quick‐frozen sweet dumplings. OβG reduced freezable water and increased the proportion of strongly bound water, indicating improved water retention within the dough matrix. As the OβG concentration increased, the time required to pass through the maximum ice‐crystal formation zone (−1°C to −5°C) decreased from 650 s for CK to 150 s at 4.0% OβG, while the total time to reach −18°C decreased from 2450 to 1100 s. These changes were accompanied by reduced water loss, improved broth clarity, better textural properties, and a more compact microstructure. The freeze–thaw cracking rate decreased from 100% in CK to 0% at OβG concentrations ≥3.2%. OβG also altered the structural organization of starch, with changes in short‐range order and relative crystallinity depending on the OβG concentration. In vitro digestion showed that OβG reduced rapidly digestible starch and slowly digestible starch while increasing resistant starch. Among the tested concentrations, 2.4% OβG provided the most favorable sensory and textural properties. Overall, OβG improved the quality and freeze–thaw stability of quick‐frozen sweet dumplings by regulating water distribution and starch structure, while also modulating starch digestibility.