Interaction between potato starch and Tremella fuciformis polysaccharide

In order to elucidate the mechanism of interaction between Tremella fuciformis polysaccharide (TP) and potato starch (PS), PS-TP composites with different concentrations of TP were prepared, and their physicochemical properties, in vitro digestibility characteristic and microstructure were investigated. The results showed that TP could significantly inhibit the swelling of potato starch granules and amylose leaching. TP could complex with the starch, and the complex indexes of the composites significantly went up from 10.04% to 52.89% when the concentration of TP increased from 0.1% (w/v) to 0.4%. Differential scanning calorimetry results indicated that TP could increase gelatinization temperature and significantly decrease the enthalpy of potato starch, thus delaying its gelatinization. Based on micromorphology analyses, the composite gels appeared to be stronger rigid and denser structure and a physical barrier was observed around the starch granules. Fourier transform infrared (FTIR) spectra revealed that the interaction of TP and starch resulted in an increase in the short-range ordered structure of the starch. TP could interact with leached amylose molecules mainly through hydrogen bond affecting the contents of RDS, SDS and RS fractions. This study can not only further enrich the theory of starch-polysaccharide interactions, but also shows the possible application of TP in hypoglycemic food products.