Comprehensive analyses of membrane lipids and phenolics metabolisms reveal the developments of chilling injury and browning in Chinese olives during cold storage. (1st August 2023) - Kuang, Xiaoyong
Highlights: 2 °C induced chilling injury and browning development in Chinese olive fruit. 2 °C increased the activities of membrane metabolism enzymes in Chinese olive fruit. 2 °C stimulated the membrane lipid degradation in Chinese olive fruit. 2 °C raised the activities of phenolics oxidation enzymes in Chinese olive fruit. 2 °C reduced the contents of phenolic substances in Chinese olive fruit. Abstract: The impacts of chilling injury (CI) temperature (2 °C) and non-CI temperature (8 °C) on the CI development, browning occurrence, and its underlying mechanism in Chinese olives were investigated. The results showed that, 2 °C induced higher levels of CI index, browning degree, chromaticity a* and b* values, but lower values of h°, chlorophyll and carotenoid contents in Chinese olives as compared to 8 °C. Furthermore, 2 °C raised cell membrane permeability, increased the activities of phospholipase D, lipase and lipoxygenase, accelerated the hydrolyses of phosphatidylcholine and phosphatidylinositol to phosphatidic acid, and promoted the conversions of unsaturated fatty acids to saturated fatty acids in Chinese olives. Moreover, 2 °C-stored Chinese olives showed higher activities of peroxidase and polyphenol oxidase, but lower contents of tanin, flavonoid and phenolics. These findings demonstrated that the CI and browning developments in Chinese olives were closely associated with the metabolisms of membrane lipid and phenolics.