Impact of glucansucrase treatment on structure and properties of maize starch

A glucansucrase isolated from Leuconostoc citreum SK 24.002 has the ability to catalyze transglycosylation and/or hydrolysis reactions on differently linked α‐glucose polymers. In this study, maize starch was modified using L. citreum glucansucrase, and its structure and properties were investigated. The total content of oligosaccharides was 2.72% for glucansucrase‐treated starch. The modified starch had a higher amylose level and molecular weight than did native starch. The chain‐length distribution showed a greater number of short (degree of polymerization, DP < 13) and long (DP > 30) branched chains in the modified starch. Compared with the native starch, the modified starch displayed a lower gelatinization enthalpy and a wider melting temperature range. The Englyst assay revealed that enzymatically modified starch had higher SDS and RS contents. Both the changes in molecular weight and the fine‐chain structure in the treated starches likely contribute to its low digestion capacity.