Responses of Chinese olives to low-temperature storage at different harvest dates involve the metabolisms of ROS,...

This work evaluated the influences of harvest dates on chilling injury (CI) and the metabolism of reactive oxygen species (ROS), membrane lipids, and phenolics in Chinese olives. Among the tested dates (I, III, V, VII), determined by Chinese solar terms and maturity indicators, Chinese olives harvested on date V exhibited the lowest levels of CI, browning, O₂^·-, and MDA, alongside the highest levels of antioxidant enzymes and substances. Moreover, Chinese olives harvested on date V displayed the lowest activity of membrane lipid-degrading enzymes and maintained higher unsaturation of membrane fatty acids. Also, these Chinese olives displayed the lowest activities of PPO and POD, while exhibiting the highest levels of PAL, flavonoids, and total phenolics. These findings imply that harvest date V (Start of winter, 7 November) is optimal for minimizing CI in Chinese olives by improving antioxidant capacity, reducing cell membrane degradation, and mitigating phenolic oxidation during cold storage.