Comparative study of multi-scale structure and in vitro digestibility between high-resistant-starch wheat and normal
Kaiyang Ma1, Youe Zhang1, Haiyu Wu1
1College of Food Science and Engineering, Northwest A&F University, Yangling 712100, China.
None:
In this study, the physicochemical properties, molecular weight, chain-length distribution, hierarchical structures, and in vitro digestive behaviors of starches from two high-resistant-starch wheat (HRSW) cultivars (TSM1 and XN836) and one normal wheat (NW, XN369) were investigated. Compared with NW, HRSW starches exhibited smaller granule size, lower molecular weight, and reduced amylopectin branching, but higher solubility, swelling power, pasting temperature, and single-helix content. In vitro digestion analysis revealed that native HRSW starch contained significantly higher resistant starch (45.5-50.6%) than NW (44.0%), which remained relatively high even after gelatinization (32.8-39.3%). Digestive kinetics modeled using the logarithm of slope (LOS) and combined-parallel-sequential (CPS) models demonstrated a biphasic digestion pattern, with HRSW showing slower digestibility and delayed initiation of the slowly digestible fraction compared with NW starch. TSM1, as a novel cultivar, exhibited the strongest digestive resistance, indicating its superior potential as a raw material for developing low-glycemic and functional foods.
