GA₃ Treatment Delays the Deterioration of ‘Shixia’ Longan during the On-Tree Preservation and Room-Temperature Storage and Up-Regulates Antioxidants

• 發表在: Foods
• Main Authors: Tao Luo, Xiaolan Lin, Tingting Lai, Libing Long, Ziying Lai, Xinxin Du, Xiaomeng Guo, Liang Shuai, Dongmei Han, Zhenxian Wu
• 格式: Article
• 語言: 英语
• 出版: MDPI AG 2023-05-01
• 主題: longan (<i>Dimocarpus longan</i> Lour.) fruit; preharvest GA₃ treatment; antioxidants; total flavonoid content; total phenolic content; storability
• 在線閱讀: https://www.mdpi.com/2304-8158/12/10/2032

Gibberellic acids had been proven to improve the fruit quality and storability by delaying deterioration and maintaining the antioxidant system. In this study, the effect of GA₃ spraying at different concentrations (10, 20, and 50 mg L⁻¹) on the quality of on-tree preserved ‘Shixia’ longan was examined. Only 50 mg L⁻¹ GA₃ significantly delayed the decline of soluble solids (22.0% higher than the control) and resulted in higher total phenolics content (TPC), total flavonoid content (TFC), and phenylalanine ammonia-lyase activity in pulp at the later stages. The widely targeted metabolome analysis showed that the treatment reprogrammed secondary metabolites and up-regulated many tannins, phenolic acids, and lignans during the on-tree preservation. More importantly, the preharvest 50 mg L⁻¹ GA₃ spraying (at 85 and 95 days after flowering) led to significantly delayed pericarp browning and aril breakdown, as well as lower pericarp relative conductivity and mass loss at the later stages of room-temperature storage. The treatment also resulted in higher antioxidants in pulp (vitamin C, phenolics, and reduced glutathione) and pericarp (vitamin C, flavonoids, and phenolics). Therefore, preharvest 50 mg L⁻¹ GA₃ spraying is an effective method for maintaining the quality and up-regulating antioxidants of longan fruit during both on-tree preservation and room-temperature storage.