Physicochemical properties of enzyme and heat-moisture treated castanea henryi starches

Castanea henryi starches were treated by enzyme and heat-moisture and the effects of enzyme dosage and reaction time on their physicochemical properties were studied. The results demonstrated that crystal types of enzyme and heat-moisture treated starches belonged to type A, which were low expected glycemic index (pGI) foods because of most pGI below 55%. By analysis in vitro digestion dynamics, scanning electron microscope (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and high performance anion-exchange chromatography with pulsed ampere detection (HPAEC-PAD), the resistant starch (RS) content, molecular chain average degree of polymerization (DP), relative crystallinity and melting enthalpy of enzyme and heat-moisture treated starches along with the change of enzyme dosage and debranching time were characterized by three phases. Especially in the second phase, namely the enzyme dosage with 50~60 U/g and the reaction time within 12~16 h, the RS content, relative crystallinity and melting enthalpy were maximum due to the molecular chain of DP value suitable to reaggregate to form stable crystalline structure. ©, 2015, Chinese Society of Agricultural Machinery. All right reserved.