Mechanistic insights into how β-glucan regulates the digestion behavior of sweet dumplings based on multi-scale structural evolution

To mitigate the high estimated glycemic index of sweet dumplings, β-glucan incorporation may serve as an effective strategy to reduce enzymatic digestibility. In this work, the effects of oat β-glucan addition (1–5%) on the digestion behavior and multi-scale structure (e.g., microstructure, nano-aggregated structure and crystalline structure) of sweet dumplings were systematically investigated. The underlying mechanism by which β-glucan regulates the digestion behavior of sweet dumplings was also elucidated. Results indicated that β-glucan addition significantly increased the resistant starch (RS) content of sweet dumplings (7.7–22.7%) while reducing the estimated glycemic index (75.89–66.92) and these changes displayed an evident dose-dependent relationship. Structural analyses revealed that the addition of β-glucan could enhance the density of nano-aggregate (α), microphase heterogeneity (ε, 3.15–3.53), relative crystallinity (RC, 11.5–15.4%) and short-range ordered degree (R1047/1024, 0.77–1.04) of sweet dumplings, suggesting the formation of dense gel network structure, well-organized nano-aggregated structure and ordered molecular structure. These multi-scale structural alterations may be mediated by hydrogen bonding and electrostatic interactions between rice flour components and β-glucan, thereby reducing both the hydrolysis rate and extent of sweet dumplings. Collectively, these findings may provide valuable insights into developing health-oriented sweet dumplings with tailored digestibility.