The physicochemical properties, and post-fermentation prebiotic properties of the type 3 resistant starch from Canna edulis modified with salvianolic acid B

Salvianolic acid B (SA) has significant regulatory effects on glucolipid metabolism. Combining SA with resistant starch endowed this type of starch with unique functional properties. This study represents the first direct complexation between SA and Canna edulis type 3 resistant starch (RS3). The findings indicated that SA has a beneficial effect on the physicochemical and prebiotic properties of RS3. SA and RS3 form a complex via non-covalent interactions, thereby increasing the crystalline and gelatinization temperatures. The 1 H NMR spectrum exhibited aromatic ring signals and increased hydroxyl signal intensity. Concurrently, the solubility of SA-RS3 decreased after composite formation, while the expansion, water absorption index and resistant starch content (59.40%) increased markedly. Fermentation analysis revealed decreases in pH and increases in reducing sugar content, in vitro antioxidant activity and hypoglycemic activity. Interestingly, SA-RS3 substantially increased the relative abundance of the Firmicutes and Actinomycetes phyla, promoted the proliferation of the beneficial bacterium Bifidobacterium , inhibited the growth of Klebsiella and Sutterella , and increased the content of acetic, propionic, and butyric acids. This indicates that SA confers antioxidant properties while retaining the prebiotic properties of raw RS3. Consequently, SA-RS3 demonstrates potential for blood glucose regulation and exhibits in vitro prebiotic properties, offering a novel direction for the development of RS3-type functional foods.