Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization, Key Laboratory of Tropical and Subtropical Fruit Tree Researches, Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Ministry of Agriculture, Guangzhou 510640, China.
Molecules. 2021 Feb 23;26(4):1181. doi: 10.3390/molecules26041181.
Litchi is an important fruit cultivated in tropical and subtropical areas with high nutritious and delicious flavor and the pulp is the main part of the fruit consumed. Previous studies found that litchi had high total phenol content and antioxidant activity, but most of them focused on the identification of single or a few phenolic components with a low throughput test, and the metabolic differences of cultivars are still unknown to a some extent. In this study we used widely targeted metabolome based on ultra-performance liquid chromatography coupled with mass spectrometry (UPLC-MS/MS) to analyze the polyphenol metabolites of five different genotypes of mature litchi fruit. A total of 126 polyphenol metabolites in eight categories were identified to reveal the composition and differences of polyphenol; 15 common differential metabolites and 20 specific differential metabolites to each cultivar were found for the first time. The results infer that flavonoids, flavonols, hydroxycinnamoyls and catechins are the main polyphenol metabolites of litchi pulp. Cluster analysis showed that there were three groups of polyphenols from high to low; early maturing Feizhixiao is a kind of high polyphenol content cultivars, especially in catechins, anthocyanins, flavonols, quinic acids and hydroxycinnamoyls. The polyphenols in the flesh of mature litchi are rich, and there are significant differences among cultivars; there was a level of correlation between the contents of phenolics and the maturity of litchi cultivars; the content of phenolics in early maturing litchi cultivars appeared higher than those of mid- to late-maturing cultivars. This experiment will provide significant reference information for cultivation, breeding, processing and consumption.
荔枝是热带和亚热带地区重要的水果之一，具有高营养价值和美味的口感，果肉是果实的主要食用部分。先前的研究发现，荔枝总酚含量和抗氧化活性较高，但大多数研究集中在单一或少数几种酚类成分的鉴定上，且品种间的代谢差异在一定程度上仍不清楚。本研究采用基于超高效液相色谱-串联质谱（UPLC-MS/MS）的广泛靶向代谢组学方法分析了五个不同基因型成熟荔枝果实的多酚代谢物。共鉴定出 126 种 8 类多酚代谢物，揭示了多酚的组成和差异；首次发现 15 种共有差异代谢物和 20 种特定差异代谢物。结果推断，类黄酮、类黄酮醇、羟基肉桂酰基和儿茶素是荔枝果肉中主要的多酚代谢物。聚类分析表明，多酚可分为三组，从高到低依次为：早熟的妃子笑是一种高多酚含量的品种，特别是在儿茶素、花青素、类黄酮、奎宁酸和羟基肉桂酰基。成熟荔枝果肉中的多酚含量丰富，品种间差异显著；酚类物质的含量与荔枝品种的成熟度呈正相关；早熟荔枝品种的酚类物质含量高于中晚熟品种。本实验将为荔枝的栽培、选育、加工和消费提供有意义的参考信息。
