Effects of chlorella peptides on physicochemical properties, in vitro digestibility and glucose metabolism of corn starch

This study explores the effect of chlorella peptides (CP) on the physicochemical properties, in vitro digestibility, and glucose metabolism of corn starch after co-gelatinization. Our in vitro digestion results revealed that CP improved the digestibility of corn starch by increasing its resistant starch (RS) content. We found that CP interacts with starch via hydrogen bonding and hydrophobic interactions, enhancing its short-range ordered structure — a novel mechanism for reducing digestibility. This effect, which is independent of the long-range ordered structure, is further supported by CP's ability to noncompetitively inhibit α-amylase and obstruct starch gelatinization. Further in vivo studies using zebrafish demonstrated that CP significantly increased the alpha and beta diversity of gut microbiota and promoted the enrichment of beneficial bacteria, which played a crucial role in improving glucose metabolism. This research provides significant insights into the mechanisms by which aquatic plant proteins can slow down starch digestion, paving the way for the development of novel slow-digestion functional foods.