Plasma-activated water for sustainable postharvest preservation of fruits and vegetables: mechanistic insights into physiological regulation and stress priming.

Plasma-activated water (PAW), predominantly generated via non-equilibrium cold plasma, is an innovative chemical-free technology for postharvest preservation. Operating at near-ambient temperatures, offering significant advantages over traditional preservation methods. Existing reviews have mostly focused on PAW's macroscopic antimicrobial efficacy and shelf-life extension. By contrast, this review systematically dissects the mechanism-driven efficacy of PAW in preserving postharvest fruits and vegetables quality, with a core focus on reactive oxygen and nitrogen species (RONS)-mediated molecular regulation and stress priming-a critical research gap insufficiently addressed in prior work. RONS from PAW directly inactivate spoilage and pathogenic microorganisms by disrupting their cell membrane integrity and central metabolic pathways. Meanwhile, exogenous RONS modulate endogenous reactive oxygen species homeostasis via activating antioxidant signaling, upregulating key defense enzymes to mitigate oxidative damage. PAW also regulates core metabolic pathways to maintain sensory quality, and enhances nutritional value by stimulating the phenylpropanoid pathway to accumulate phenolic and flavonoid bioactives. Furthermore, PAW induces stress priming by mimicking mild abiotic stress, activating mitogen-activated protein kinases (MAPK) signaling and defense-related gene expression to boost produce resilience against subsequent biotic and abiotic stresses during transport. Critically, this review establishes a full-chain regulatory framework of "exogenous RONS stimulation-intracellular signal cascade amplification-physiological metabolic reprogramming-stress resilience enhancement", identifies key knowledge gaps, and summarizes core bottlenecks and targeted solutions for PAW's industrial translation. It bridges low-temperature plasma processing, mechanistic food science and sustainable food security, providing a theoretical perspective and application roadmap for PAW's industrial deployment in postharvest food engineering.