为研究梯度回温对低温贮藏荔枝货架期品质保持的作用，以“八月红”荔枝为实验材料，经过1 d贮藏后，依次经过9、18和25 ℃三个温度环境后逐渐回到室温（25 ℃），设为“梯度回温”处理组，同时设置1 d贮藏后直接放入25 ℃环境恢复室温（25 ℃）的荔枝为“直接回温”处理组作为对照，分别模拟货架在常温放置0、1、3、5 d，并对货架期荔枝果实各项指标进行测定。结果表明，“梯度回温”处理能够缓解荔枝褐变，回温处理后在常温放置5 d时，“直接回温”荔枝的褐变指数为1.50，“梯度回温”荔枝的褐变指数仅为1.00。此外检测发现“梯度回温”延缓了可溶性固形物、可滴定酸、总酚、类黄酮、花青素含量的减少，并有效抑制了果皮中多酚氧化酶和过氧化物酶活性的增加。因此，采用梯度回温方式处理能有效缓解低温贮藏荔枝品质劣变，延长货架保鲜期，具有广阔的应用前景。

In order to investigate the impact of gradient warming on the shelf life of litchi stored at low temperature, "August Red" litchi was selected as the experimental material. After being stored at 1 d, the litchi fruits were gradually brought back to room temperature (25 ℃) through three different temperature environments: 9, 18, and 25 ℃. This treatment group was referred to as the "gradient rewarming" group. Simultaneously, another group of litchi fruits stored at 1 d were directly exposed to a room temperature environment (25 ℃) for restoration purposes and served as the control group. The simulated shelves were placed under room temperature conditions for durations of 0, 1, 3, and 5 d respectively in order to test various indexes related to litchi fruit quality during its shelf life. The results demonstrated that the "gradient rewarming" treatment effectively mitigated browning in litchi fruits. Specifically, after undergoing the "gradient rewarming" treatment followed by placement at room temperature for five days, the browning coefficient of these fruits was only 1.00 compared to a browning coefficient of 1.50 observed in those subjected solely to direct warming method. Furthermore, it was observed that "gradient rewarming" delayed decreases in soluble solids content, titratable acids content, total phenols content , flavonoids content ,and anthocyanins content while also effectively inhibiting increases in polyphenol oxidase and peroxidase activities within their peels. Therefore, the use of gradient rewarming treatment can effectively alleviate the quality deterioration of litchi stored at low temperature, extend the shelf life, and have a broad application prospect.

广东省区域创新能力与支撑保障体系建设专项(2023B0202090004)；广州市重点研发计划项目（2023B01J2001）