Recent trends in hydrogen-associated treatments for maintaining the postharvest quality of fresh and fresh-cut fruits and vegetables: A review

The majority of fruits and vegetables are perishable, thus finding sustainable postharvest treatments to regulate the quality of fresh produce is imperative. Recent research has demonstrated that the exogenous application of hydrogen (H-2)-associated treatments such as H-2 gas or hydrogen-rich water (HRW), hydrogen sulfide (H2S), and hydrogen peroxide (H2O2) at optimal concentrations can significantly maintain the quality of postharvest fruits and vegetables. The understanding of mode of action of such treatments for quality maintenance and shelf-life extension of harvested fruits and vegetables has undergone substantial development in recent years. This paper addressed recent trends in functionalities of H-2-associated treatments, summarizes the modulations led by possible mechanism of action, lab-scale production strategies, quality-regulating aspects at both physiological and transcriptomics levels, and limitations in H-2-associated treatments for maintaining postharvest quality of fresh and fresh-cut fruits and vegetables, and suggests future research directions aimed at developing sustainable H-2-associated postharvest treatment. The key findings of this review mainly concluded that H-2-associated treatments are proven to be promising approaches for maintaining the quality of fresh and fresh-cut fruits and vegetables, notably by delaying senescence, reducing softening, alleviating chilling injury, lowering the browning, and limiting microbial proliferation by modulating gas respiratory, antioxidant, and peroxiredoxin/thioredoxin systems; phenylpropanoid, GABA-shunt, and AsA biosynthesis pathways; mitochondrial energy, cell wall, color, proline, and lipid metabolisms, and ROS and RNS homeostasis. Future research direction emphasizes the application of hydrogen nanobubble water (HNW), and H-2-associated treatments in combination to regulate overall quality of fresh and fresh-cut fruits and vegetables.