A Hydrophobic Structure Assembled Based on Zein Inhibits the Occurrence of Wheat Preharvest Sprouting

Global climate-related disasters have made preharvest sprouting (PHS), a critical constraint on improving wheat yield and quality. Current prevention strategies primarily rely on breeding new varieties, which face challenges such as prolonged breeding cycles and the difficulty of balancing high yield/quality with sprouting resistance. Meanwhile, existing chemical control agents suffer from inconsistent efficacy, instability, and risks of nonpoint source pollution. In this study, an eco-friendly silicon dioxide nanoparticle/chitosan/zein composite (SCZ) was developed using zein as the natural hydrophobic agent, chitosan (CS) as a base membrane-forming polysaccharide, and silicon dioxide nanoparticles (SiO2 NPs) as filler, each at a final concentration of 1% (w/v). Through optimized ingredient ratios and application methods, field trials demonstrated that SCZ spray achieved over 40% control efficacy against wheat PHS. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) characterization indicated that SCZ formed a compact composite structure with hydrophobic characteristics on the wheat grain surface. This structure blocked water infiltration and thereby inhibited preharvest sprouting. Physiologically, SCZ treatment reduced malondialdehyde (MDA) accumulation and suppressed peroxidase (POD) and alpha-amylase (α-amylase) activation during germination, indicating that SCZ inhibits preharvest sprouting by alleviating oxidative damage and limiting starch mobilization. This research provides theoretical insights into PHS control mechanisms and proposes a novel approach for developing green antisprouting agents, offering significant economic benefits and promising application prospects for sustainable wheat production.