Biochemical profile and quality variations during storage of wild leafy vegetables: The antagonistic role of copper and ascorbic acid

Wild leafy vegetables (WLVs) are valuable components of traditional diets due to their rich phytochemical content and potential health benefits. However, their perishability after harvest limits their use and commercial potential. This study investigated the postharvest quality dynamics of eight WLV species, focusing on biochemical changes including pigment content, total phenolic content (TPC), and antioxidant activity. Additionally, the role of phenolic compounds, copper, and ascorbic acid in tissue browning was explored. The results highlighted significant differences among species in their postharvest behaviour. The most pronounced biochemical changes occurred ten days after harvest. Alchemilla xanthochlora consistently maintained high antioxidant quality, while Bistorta officinalis preserved better overall quality. Conversely, Phyteuma betonicifolium and Blitum bonus-henricus exhibited progressive deterioration. Some species, such as Achillea millefolium and Silene vulgaris, maintained stable but moderate quality, whereas Taraxacum officinale and Plantago lanceolata showed initial suboptimal quality that worsened postharvest. This study confirmed that copper and ascorbic acid play antagonist roles in preserving antioxidants of WLVs: higher copper levels at harvest enhance postharvest o-quinone formation, whereas ascorbic acid exerts an opposing influence. Most of the studied species demonstrated the ability to retain quality for extended storage periods, suggesting opportunities for their broader inclusion in sustainable food systems.