Heat-moisture-treated rice starches with different amylose and moisture contents as stabilizers for nonfat yogurt

Food producers are interested in enhancing native starch properties without chemical modifications. Here, rice starches were physically modified via heat-moisture treatment (HMT) using different amylose (high, medium, low, and waxy) and moisture (15 %, 20 %, 25 %, and 30 %) contents. Hydration properties and pasting viscosities differed for different amylose and moisture contents. The HMT starch with high amylose content and 15 % moisture (High_HMT15) exhibited the highest final viscosity (6.16 Pa.s), and 31.7 % and 35.1 % increased amount of resistant starch compared to native starch in the granule and paste states, respectively. Hence, High_HMT15 was used as a stabilizer for nonfat yogurt. The nonfat yogurt prepared with 1.0 % High_HMT15 as the stabilizer exhibited 37.3 % reduced whey separation, 2.8 times increased viscosity, a high total solids content, and acceptable sensory properties compared to the nonfat yogurt without starch. These HMT starches can replace chemically modified starches derived from other grains in various food applications.