Improvement of functional and rheological features of tigernut tuber starch by using gum derived from Chinese quince seeds

Abstract

In this study, we investigated the influence of Chinese quince seed gum (CQSG) on the functional and rheological features of tigernut tuber starch using a rapid visco-analyzer (RVA), differential scanning calorimetry (DSC), scanning electron microscopy, and rheometry. The addition of CQSG markedly increased the pasting temperature, peak, breakdown, final viscosities, and the setback value. The freeze-thaw stability of the gum/starch blends significantly (p < 0.05) increased as the gum concentration increased, thus suggesting the importance of CQSG in controlling the syneresis of the gel. The addition of CQSG decreased the gelatinization enthalpy, ranging from 16.57 J/g to 12.98 J/g, and the solubility at 75 °C and 85 °C. Structure measurements revealed CQSG decreased the recrystallization of the gel, thus suggesting that it prevented starch gel retrogradation by likely coating the granules of starch and/or influencing the interactions of the amylose. Behavior index values (n) indicated pseudoplastic flow increased ranging from 0.46 to 0.29 as the CQSG content increased. Overall, CQSG improved the properties of the tigernut starches, in particular by increasing freeze-thaw stability, viscosity, and pseudoplasticity and by preventing retrogradation in the starch gel. CQSG is promising to improving the properties of starch-based products in the food industry.