荔枝果皮多酚提取条件优化及其在果实成熟期间的变化

Optimizing the conditions for extracting polyphenols in litchi pericarp and their variation during fruit ripening

为优化荔枝果皮多酚提取条件并确定其在果实成熟过程中的变化规律,以淮枝品种荔枝果实为试材,通过正交试验法确定果皮多酚化合物优化的提取工艺,同时利用高效液相色谱(HPLC)法分析荔枝果皮中主要多酚的化学组成及果实成熟前后其含量的变化。结果发现,在本试验条件下,固液比3∶10、提取剂甲醇/丙酮(1/1,v/v)、提取剂浓度65%、提取时间20 min的组合为荔枝果皮多酚的优化提取条件;HPLC分析表明(-)-表儿茶素(EC)、(-)-表没食子儿茶素(EGC)与原花色素A2(PA2)为荔枝果皮中的主要多酚;荔枝果实由未熟绿果发育至初熟转红果的过程中,三者含量下降,其中PA2的含量下降更快。研究可为高效提取利用荔枝果皮多酚类物质提供参考。

The study was performed to optimize the conditions for extracting polyphenols in litchi pericarp and to determine their variation rules during fruit ripening.The fruit of cultivar Huaizhi was used as experimental material and the orthogonal experimental design was involved.The major composition and content of polyphenols in unripe green fruit and ripe red fruit were analyzed using HPLC method.The results showed that the optimum extracting conditions were as follows：the ratio of material and solvent was 3︰10,solvent methanol/acetone（1/1,v/v） at 65%,and the extracting time 20 min.The major polyphenols in litchi pericarp were（-）-epicatechin（EC）,（-）-epigallocatechin（EGC） and proanthocyanin A2（PA2）.During fruit ripening,three polyphenol contents declined,especially PA2.This study provides a reference on effectively extracting and utilizing polyphenols in litchi pericarp.