Structural Remodeling, Redox Regulation, and Metabolic Responses in Cold Plasma Pretreatment-Assisted Drying of Foods: A Critical Review.

Drying is widely used to stabilize foods, but long processing times and thermal exposure increase energy demand and can impair color, texture, nutrients, and flavor. Cold plasma (CP) pretreatment has attracted interest as a nonthermal strategy for accelerating moisture removal while maintaining product quality. This critical review examines CP pretreatment-assisted drying across food materials by linking structural remodeling with redox regulation and metabolic responses. Current evidence shows that changes in surface wettability, cuticular barriers, cell-wall and membrane integrity, and pore connectivity can facilitate water migration and shorten drying. CP-associated modulation of browning enzymes, oxidative status, and bioactive or flavor-related metabolites may also influence color, antioxidant capacity, nutrient retention, and flavor. However, these effects vary with discharge mode, treatment intensity, gas composition, pressure, temperature, and food-matrix properties. Excessive exposure can instead aggravate oxidation and diminish product quality. Current mechanistic evidence is strongest for plant foods and edible fungi and remains limited for animal-source foods. Together, these findings link plasma-generated chemical and physical agents to structural, biochemical, and drying responses. They provide a basis for defining material-specific operating windows and developing reproducible, safe, and scalable CP pretreatment-assisted drying of foods.