Effects of hot air pretreatment on digestibility and quality of steamed bread

Effects of hot air pretreatment on digestibility and quality of steamed bread, including moisture content and distribution, starch characteristics and digestibility, and product quality of post-steaming were systematically investigated. The results revealed that the digestibility of starch was related to the moisture content, with lower moisture levels corresponding to lower rapidly digestible starch (RDS), and higher slowly digestible starch (SDS) and resistant starch (RS) contents. The most pronounced change occurred at 75 °C for 60 min: RDS decreased to 46.96%, SDS increased to 29.27%, and RS surged to 23.76%. Hot air pretreatment increased the hardness, adhesiveness, and chewiness of steamed bread, hich remained within an acceptable range. By adding a hot air pretreatment process before steaming, the digestive properties of steamed bread were successfully modified, providing technical insights for developing household health-oriented cooking appliances and supporting the preparation of low-glycemic-index staple foods. • Hot air pretreatment significantly reduced the digestibility of steamed bread. • Slowly digestible starch and resistant starch increased to 29.27% and 23.76% at 75 °C. • Hot air pretreatment slightly reduced the cooking quality of steamed bread. • Method enabled low-glycemic steamed bread in household cooking appliances.