Effect of persimmon tannin on the physicochemical properties of maize starch with different amylose/amylopectin ratios.

The effects of persimmon tannin (PT) on the physicochemical properties of maize starch with different amylose/amylopectin ratios were studied. The results showed that PT remarkably altered the physicochemical properties of the starch. And the effects were dependent both on the concentration of PT and the amylose/amylopectin ratios. DSC analysis showed that PT slightly increased the gelatinization temperature of low-amylose (LAC) and intermediate-amylose maize starch (IAC), whereas the Tc and Tp of high-amylose maize starch (HAC) were decreased strikingly. XRD and SEM analysis demonstrated that PT retarded the retrogradation of the three kinds of starch. The hardness and adhesiveness values of the three kinds of starch decreased with increasing the PT concentration. The cohesiveness and springiness value of LAC starch gel were decreased by PT, whereas that of HAC starch gel were slightly increased by PT addition. Dynamic rheology analysis demonstrated that PT improved the viscoelasticity of LAC paste, but lowered the viscoelasticity of HAC and IAC paste. Taken together, PT had greater effects on the physicochemical properties for HAC starch than on LAC, revealing that PT has stronger interaction with amylose than with amylopectin. Our results indicated that PT might have a potential use in improving the quality of starch-based food.