Amylopectin Molecular Structure from Different Banana Cultivars and its Influence on the Formation of Structurally-Driven Slowly Digestible Starch
In high glycemic index starchy foods, hydrothermal processing causing gelatinization results in starch being more rapidly digested by α-amylase. Understanding the structural properties that increase the propensity to form structurally-driven slowly digestible starch (SSDS) would have major impact on consumer health. Starch from 6 banana cultivars (Enano Gigante, Morado, Dominico, Hembra, Macho, and Manzano) were analyzed for their structural, functional and digestive properties. Digestion of all banana cultivars was found to be two-fold lower than the maize counterpart after one and 7 days storage, most noticeably in Manzano. The combination of higher amylose content, smaller amylopectin molecular weight, and lower proportion of A-chain fingerprints could result in higher mobility and better alignment properties of amylopectin, leading to the formation of more SSDS. Results from this study will contribute towards a better understanding of banana starch structural properties and their role in developing low glycemic index foods.