Effects of tamarind seed polysaccharide on gelatinization, rheological, and structural properties of corn starch with different amylose/amylopectin ratios

Abstract

Tamarind seed polysaccharide (TSP) is commonly used as a stabilizer, suspending agent, and thickener. In this study, the effects of tamarind seed polysaccharide on gelatinization, and the rheological and structural properties of waxy (WCS), normal (CS), and high amylose corn starch (HACS) were investigated. Rapid visco analysis (RVA) and thermal property analysis demonstrated that TSP molecules bind with starch granules to retard gelatinization. Steady flow test results showed that corn starch with different amylose/amylopectin ratios in the absence or presence of TSP presented non-Newtonian fluid properties. Further, the CS or WCS with TSP mixtures exhibited a typically rheological behavior of weak gel. TSP molecules enhanced the elastic properties of high amylose corn starch gels. The presence of TSP also influenced water distribution in the starch-TSP mixture system. Structural characteristic analysis suggested that TSP bound with starch molecules to change their conformation, and influence the gelatinization of starch, especially for amylopectin. The results demonstrated that TSP changes the physicochemical and structural properties of starch through interaction with it, and facilitates the effective bonding with amylopectin.