Insights into the structural, morphological, and thermal property changes in simulated digestion and fermentability of four resistant starches from high amylose maize starch

Changes in the structural, morphological, and thermal properties of four types of resistant starch (RS), including native (RS2), retrograded (RS3), chemically modified with octenyl succinic anhydride (RS4), and complexed with stearic acid (RS5), were investigated and compared in salivary, salivary-gastric, and salivary-gastric-intestinal digestion. In the process of digestion, the crystal types of RS2, RS3, RS4, and RS5 remained unchanged, maintaining a B-type structure, except for the missing V-type structure of RS5. The total short-chain fatty acid yield of RS2 was significantly higher than that of RS3, RS4, and RS5 at 6 and 12 h of fermentation. RS2 and RS4 had a better proliferation effect on Bifidobacterium in late fermentation than RS3 and RS5, while RS3 could promote proliferation to a larger extent in early fermentation. RS2, RS3, and RS5 had more obvious proliferation effects on Lactobacillus in the late fermentation period. This work suggests that the type of RS plays an important role in influencing the structural and digestive properties of RS during gastrointestinal digestion and can be used to develop formulations of healthy starch-based products with desired functionalities.