Plasma Effect on Germination and Physicochemical Properties of Moist Wheat Grain

This study investigates the effects of dielectric barrier discharge (DBD) cold plasma treatment on the germination and physiological responses of wheat grains with 16% moisture content, simulating wet storage conditions. Wheat seeds were treated under 60 V, 70 V, and 80 V for 90 s. Germination parameters, seedling growth, enzymatic activities, and surface modifications were analyzed. Results showed that plasma treatment significantly reduced germination rate, germination potential, and vigor index in a voltage-dependent manner (p < 0.05). The highest voltage (80 V) decreased germination rate by 46% compared to the control. Seedling growth, including shoot/root length and fresh/dry weight, was also suppressed. Biochemical assays revealed reduced activities of α-amylase, protease, lipase, and polyphenol oxidase (PPO), indicating inhibited nutrient mobilization and metabolic processes. Antioxidant enzymes (catalase and peroxidase) showed varying responses, likely due to oxidative stress induced by reactive oxygen and nitrogen species (RONS). Scanning electron microscopy (SEM) demonstrated plasma-induced etching and structural damage to the seed coat, while Fourier transform infrared spectroscopy (FTIR) confirmed no new chemical bonds formed. These findings suggest that cold plasma treatment disrupts seed structure and enzymatic activity, thereby inhibiting germination and seedling growth. The study highlights the potential of plasma technology for post-harvest management of wet grains to prevent premature sprouting and preserve quality.