ABSTRACT This work aimed to analyze the structure, physicochemical characteristics and in vitro digestibility of wheat starch (WS) in complexation with epicatechin (EC) as well as its interaction on the food quality of noodles. Results of SEM, FT‐IR, and XRD indicated that interacting with EC increased the short‐range ordered degree and crystallinity of WS, forming a compact structure. The additional peaks during 6–9 ppm in 1 H NMR spectra of WS–EC complexes were attributed to the benzene rings and hydroxyls derived from EC. The reduced mass loss of WS–EC complexes in the thermogravimetric curve demonstrated a higher thermal stability of starch induced by EC. Complexation decreased swelling power and solubility of WS and significantly increased resistant starch content by 52.52% (5% EC), resulting in an obviously decreased glycemic index (GI) value due to the comprehensive effects of the EC‐induced ordered structure and inhibition on starch hydrolase. This was further verified in wheat noodles, wherein EC improved the whiteness, viscoelasticity and cooking loss of noodles without influencing sensory score but significantly reduced its postprandial blood glucose elevation potential. Hence, WS–EC complexes could be utilized as a functional component to develop foods with low‐GI value.
Zhang et al. (Wed,) studied this question.