Abstract:
The components and structures of proteins critically determine the food-use properties of wheat. However, the mechanism by which sulfur affects the protein structures and cookie-making quality of wheat grown under shading remains elusive. Here, we evaluated the combined effects of inorganic sulfur supplementation (0, 50, and 100 kg S ha− 1 ) and shading (pre- and post-anthesis shading) on the protein structures and cookie-making quality of strong-gluten (Chuanmai 39; CM39) and weak-gluten (Cangmai 34; CM34) cultivars. Shade stress decreased the ω-/(α, β, γ)-gliadin and high-molecular-weight subunit (HMW-GS)/low-molecular-weight subunit (LMW-GS) glutenin ratios, with more signiffcant effects were observed in CM34 than in CM39. In shaded environments, sulfur increased the glutenin/gliadin and HMW-GS/LMW-GS ratios. Secondary and tertiary structural analysis revealed that sulfur increased the β-turn, disulffde bonds, ionic bonds, and hydrophobic interactions in the proteins of wheat under shading. The consequent modiffcations increased the gluten performance index, essential amino acid index and biological value of the proteins, and decreased cookie hardness. Our results revealed that sulfur improves cookie texture and protein nutritional value by regulating amino-acid proffles and protein composition and structure. These ffndings provide a promising approach for achieving superior cookie texture in the context of global dimming.
