Effects of flour types and fermentation times on low-protein steamed buns

Low-protein foods have attracted much attention in the medical field. Herein, low-protein steamed buns (LPSBs) were prepared, and their properties were evaluated. The flour types, yeast/flour ratios, fermentation temperatures, and fermentation times were optimized to obtain LPSBs with smooth surfaces and internal porous structures. The LPSBs had a low protein content (0.50 g/100 g) and 80 volatile organic compounds (VOCs). The LPSBs made with different types of flour had distinct characteristic VOCs, allowing for their differentiation. In addition, 10 yeast-metabolism-derived VOCs were identified in the LPSBs. The post-storage textural properties were affected by the flour types, fermentation times, storage temperatures, and storage times. The flours and fermentation times affected the in vitro starch digestion rates. Finally, the LPSBs had lower consumer's acceptability than the steamed bun made with medium-gluten flour. The obtained results are beneficial for understanding the effects of flour types and fermentation times on the properties of LPSBs. • Special low-protein steamed buns (LPSBs) were prepared at the optimized conditions. • LPSBs had 67 volatile organic compounds (VOCs) identified using HS-GC-IMS. • Two LPSBs had 7 and 4 VOCs as characteristic ones for differentiating them. • Textural properties were partially affected by the flours, fermentation, and storage. • LPSBs had starch hydrolysis rates of 40.2–43.1 % after 3 h in vitro digestion process.