Effects of quercetin and Ca(OH)2 addition on gelatinization and retrogradation properties of Tartary buckwheat starch
Qiling Cai, Xiaoping Li, Xinxin Ding, Haorui Wang, Xinzhong Hu
Abstract
In this study, effects of separate and synergistic addition with quercetin (Q) and Ca(OH)2 (named TBSQ, TBSCa, and TBSQCa) on gelatinization and retrogradation characteristics of Tartary buckwheat starch (TBS) were investigated. Swelling power, solubility, and paste viscosity of TBSQCa were higher than TBSQ, and lower than TBSCa, indicating that Ca(OH)2 alleviated the restriction of quercetin on TBS gelatinization, that was also confirmed by images at nanometer scale from atomic force microscope. Retrograded TBSQ, TBSCa, and TBSQCa presented lower enthalpy, relative crystallinity, and degree of order than TBS, manifesting retrogradation of TBS can be delayed by quercetin and Ca(OH)2. Morphology of SEM and texture analysis revealed that the Ca2+, Ca(OH)+, and alkaline conditions promoted the interaction among starch, quercetin and Ca(OH)2, eliminated the influence of quercetin as a rigid filler on starch, and formed higher strength gel in TBSQCa. These findings proclaimed effective action of Ca(OH)2 in quercetin-rich starch-based foods.