Influence of Chain Length on α‐1,4‐D‐Glucan Recrystallization and Slowly Digestible Starch Formation

Short-chain α-(1,4)-D-glucan samples were generated by debranching of potato amylopectin and fractionation on gel permeation chromatography. The collected fractions were gathered to generate two samples with an average DPn of 32 and 42, respectively. The samples were recrystallized at −80 and 1°C for three days (10%, w/w) and the resulting structures and related digestibility were assessed. The results revealed that the slowly digestible starch (SDS) content was affected by both chain length and recrystallization temperature. The highest SDS level (49%) was obtained at −80°C from the sample with the lowest average DPn. Its structure showed B-type polymorphic crystallites with a substantial amorphous part and a melting temperature of 85°C. Such a melting temperature was close to that already reported in the literature and appears characteristic of recrystallized SDS structures.