The riboflavin-mediated reprogramming of specialized metabolites enhances postharvest cold tolerance and functional traits of zucchini fruits

Shelf-life extension has a pivotal role in postharvest since fruits are cold-stored to slow down respiration and metabolic processes associated with degradation. When stored at low temperatures, zucchini fruits (Cucurbita pepo L.) are prone to chilling injury, which causes surface damage and reduces quality and nutraceutical value, leading to substantial economic losses. Recent studies featured riboflavin as an enhancer of postharvest cold tolerance in fruits inducing antioxidant defense mechanisms. This work aimed to elucidate the metabolic changes triggered by riboflavin in zucchini fruits during cold storage to extend postharvest shelf life and increase nutraceutical properties. A broad metabolic reprogramming was revealed, with terpenoids and phenolic compounds being the most differentially accumulated metabolites during cold storage. Additionally, riboflavin was found to influence the biosynthesis of alkanes, diacylglycerols, triacylglycerols, phytohormones, and vitamins. This metabolomic shaping supports shelf-life extension and the increase in antioxidant properties of zucchini fruits.