Huang Hua, Wang Ling, Bi Fangcheng, Xiang Xu
Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences; Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Tropical and Subtropical Fruit Tree Research, Guangzhou, China.
Sericultural & Agri-Food Research Institute Guangdong Academy of Agricultural Sciences, Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs, Key Laboratory of Agricultural Products Processing, Guangzhou, China.
Front Nutr. 2022 Mar 17;9:849385. doi: 10.3389/fnut.2022.849385. eCollection 2022.
Litchi fruit contains abundant polyphenols and is susceptible to browning after harvest. Herein the combined treatments of malic acid (MA) and lycopene (LYC) to delay the development of browning in litchi fruit stored at room temperature (25°C) and low temperature (4°C) was investigated. The results showed that the pericarp browning could be alleviated, and the increase of malondialdehyde (MDA) content and relative leakage rate was retarded by the combined MA and LYC during storage. As compared to control, the content of pericarp anthocyanins, flavonoids, and the total phenols maintained higher levels; and the decrease of antioxidant activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity and reducing power were slowed down in treated fruit. The enzyme activity of polyphenol oxidase (PPO) and peroxidase (POD) related to oxidation of polyphenols were depressed by the combined treatments. Furthermore, correlation analysis revealed that the content of phenols in the pericarp negatively affected the changes in the browning index, and was positively related to the DPPH radical scavenging capacity. Taken together, the combined treatments of MA and LYC exhibited potential effects in delaying the pericarp browning of litchi fruit by maintaining the content of polyphenols, antioxidant activity, and membrane integrity.
荔枝果实含有丰富的多酚类物质，采后易发生褐变。本文研究了苹果酸（MA）和番茄红素（LYC）联合处理对室温（25℃）和低温（4℃）贮藏荔枝果实褐变发展的延缓作用。结果表明，在贮藏期间，MA和LYC联合处理可减轻果皮褐变，抑制丙二醛（MDA）含量和相对电导率的增加。与对照相比，处理后果皮中花青素、类黄酮和总酚含量保持较高水平；果实2,2-二苯基-1-苦基肼（DPPH）自由基清除能力和还原力的抗氧化活性下降减缓。联合处理抑制了与多酚氧化相关的多酚氧化酶（PPO）和过氧化物酶（POD）的酶活性。此外，相关性分析表明，果皮中酚类物质含量对褐变指数变化有负面影响，与DPPH自由基清除能力呈正相关。综上所述，MA和LYC联合处理通过维持多酚含量、抗氧化活性和膜完整性，对延缓荔枝果实果皮褐变具有潜在作用。
