Acetated starch inclusion to tailor the hierarchical structure and sol-gel features of middle gluten wheat starch-based binary matrices

Abstract

Acetate starch (AS), a starch derivative, is frequently used as a food additive to enhance the processing performance of wheat starch (WS), owing to its low degree of substitution and excellent storage stability. This study investigates the effects of AS on the hierarchical structure and sol/gel features of WS with varying amylose content within the wheat starch and acetylated starch (WS-AS) binary system, aiming to elucidate the potential practical applications of AS. In comparison to WS, the WS-AS binary system demonstrated notably reduced setback value, gel strength, hardness, zero shear viscosity, and moduli during the cooling phase, accompanied by an inhibited sol-gel transition of WS. This phenomenon is rationalized by the relatively elevated full width at half maximum FWHM_λ480 value in the binary system (increasing from 19.52 (low amylose, LA)–23.63 (middle amylose, MA) to 23.54 (LA-AS)–26.26 (LA-MS)). Furthermore, the Fourier-transform infrared spectroscopy (FTIR) analysis revealed an additive effect induced by the inclusion of AS, exhibiting a contrasting influence. As the amylose content in WS increases from 28% to 34%, the modulus and viscosity of the sol and thixotropy of the sol increase, leading to a gel with greater strength and enhanced chewability. Consequently, the WS with lower amylose content in the WS-AS binary system exhibits more desirable sol/gel properties overall.