The molecular mechanism for morphological, crystal, physicochemical and digestible property modification of wheat starch after repeated versus continuous heat-moisture treatment

摘要

To explore the mechanism of heat-moisture treatment on starches and innovate the starch modification method, the wheat starch-water suspensions were subjected to repeated and continuous heat-moisture treatment (RHMT and CHMT) and investigate the changes and connections of molecular, morphological and physicochemical properties. The results showed that treated starches had many scallops but their shape unchanged compared with native starch. Primarily, the molecular weight emerged an increasing trend of modified starch as the time prolonged, which induced the changes of physicochemical properties. The crystal form of treated starches did not change but their crystallinity decline. The viscosities and swelling force of modified starch decreased while solubility, pasting temperatures and in vitro digestibility increased than that of native starch. The RHMT exhibited a more obvious effect in molecules rearrangement and the RHMT starch had a lower molecular weight, which could be used as a great potential to modify the starch physicochemical and functional properties.