Insights Into the Digestibility, Properties, and Structure of Highland Barley Starch Using Dry Heat Treatment, Heat Moisture Treatment, and Annealing Treatment

ABSTRACT The changes of digestibility, several processing properties, and structure of highland barley starch induced by dry heat treatment (DHT), heat moisture treatment (HMT), and annealing treatment (AT) were investigated. And the interrelationship between modification conditions, structure, and functional properties was also investigated. For DHT, the starch was treated at 110°C for 4 , 8, and 12 h, respectively. For HMT, the starch was adjusted to moisture contents of 20%, 25%, and 30%, and then heated at 110°C for 4 h. For AT, the starch was treated at 50°C for 12 and 24 h, respectively. The results indicated that DHT, HMT and AT all positively impacted the total content of slowly digestible starch (SDS) and resistant starch (RS) in the starch samples, and HMT was the best method in leading to the conversion of a portion of rapidly digestible starch (RDS) into SDS and RS. Among them, HMT‐20% resulted in a decrease in the RDS content from 91.19% to 81.50%, while simultaneously causing an increase in the SDS and RS content from 5.54% and 3.27% to 8.73% and 9.77%. Moreover, HMT significantly affected the thermal properties, rheological properties, crystallinity, molecular structure, and particle morphology of starch. Therefore, our research suggested that utilizing hydrothermal treatment or heat treatment could be a potential approach for controlling the digestibility of starch products according to desired specifications. This experiment innovatively focused on highland barley starch, a less‐researched material. Using DHT, HMT, and AT, it measured different digestible starch contents and explored the links between treatment conditions, RS contents, structure, and function, providing new ideas for its application in functional foods.