Effect of β-glucans with different molecular weights on pasting, rheological, texture properties, and in vitro digestibility of normal and waxy highland barley starches

This study investigated the impact of low, medium, and high molecular weight β-glucans on physicochemical properties and in vitro digestibility of normal (NHBS) and waxy highland barley starches (WHBS). Results indicated that β-glucans with different molecular weights had varying effects on HBS properties. High molecular weight β-glucan (HBG) significantly increased the pasting temperature and gelatinization enthalpy of two HBS, and reduced the apparent viscosities. The firmness of NHBS was decreased after adding β-glucans, while the opposite result was observed in WHBS. Structural analysis showed HBG formed stronger interactions with two HBS, resulting in a more ordered structure. LF-NMR analysis revealed that β-glucans had water-binding capacities, and their interaction with water limited water access to HBS and reduced water mobility. In vitro digestion indicated that HBG significantly decreased the digestibility of NHBS and WHBS to 67.87 % and 73.85 %, respectively. HBG improved the HBS properties through its interaction with HBS and water.