Influence of starch physicochemical properties on biscuit-making quality of wheat lines with high-molecular-weight glutenin subunit (HMW-GS) absence

Abstract

The intrinsic relationship between biscuit quality and starch physicochemical properties was studied using a set of wheat lines with HMW-GS absence of Ningmai 9. The results showed that, compared with wild type, wheat lines with HMW-GS absence had higher amylose content, volume proportion of A-type starch granule, relative crystallinity (RC), peak and final viscosities, gelatinization peak temperature (Tp) and conclusion temperature (Tc), and consistency coefficient (K) of flour paste. Conversely, lower amylopectin content and ratio of absorbance 1047/1022 cm−1 (IR2) were found in these wheat lines. As a result, biscuits made of wheat lines with HMW-GS absence had better quality with higher spread ratio and lower hardness. Pearson correlation analysis showed that the difference between minor compounds contents and biscuit quality was not significant, while amylose content, volume proportion of A-type starch granule, RC, and K value were positively correlated with biscuit quality, confirming significant effects of starch physicochemical properties on biscuit quality and effective indicators for improvement of biscuit quality. Molecular mechanisms were proposed for all these observations, which not only shed light on how physicochemical properties of starch affects biscuit quality but also identified high-quality soft wheat for biscuit making by selecting starch with appropriate physicochemical features.