超声波辅助绿茶提取物的制备及多壁碳纳米管/绿茶提取物复合体系分散性能研究

Preparation of Green Tea Extract Assisted by Ultrasonic Wave and Dispersion of Multi-walled Carbon Nanotubes/Green Tea Extract Composite System

以干燥绿茶粉末为原料,食用酒精溶液为萃取液,采用超声波辅助提取制备绿茶提取物。控制萃取液浓度、固/液比及超声萃取时间,研究提取工艺,用紫外可见分光光度计对提取物中的茶多酚含量进行分析。结果表明,食用酒精溶液浓度为70%、固液比为1∶12、45℃下超声萃取60min,提取物产率和茶多酚含量最高,分别达到42.22%和22.49%。将多壁碳纳米管(MWNTs)分散到绿茶提取物水溶液中时,茶多酚的苯环与MWNTs产生π-π共轭效应并吸附在MWNTs表面,茶多酚的羟基伸向水相,使MWNTs均匀分散在水中。

Green tea extract was obtained by ultrasonic assisted extraction,in which edible alcohol solution was used as extract liquid and dried green tea powder as raw materials.Extracting process of green tea extract was studied by using different edible alcohol concentration,ratio of solid to liquid and ultrasonic extraction time.Contents of tea polyphenol in the green tea extract were determined by UV-Vis spectrophotometer.The results showed that when temperature was45℃,concentration of edible alcohol was70%,ratio of solid to liquid was1:12and ultrasonic extraction time was60min,the most yield of green tea extract and content of tea polyphenol were obtained,and reached42.22%and22.49%,respectively.When multi-walled carbon nanotubes(MWNTs)were dispersed in the tea extract water solution,phenylring moieties of tea polyphenol were adsorbed on the surfaces of MWNTs viaπ-πconjugated interaction and hydroxy groups of tea polyphenol were exposed to water phase.As a result,MWNTs dispersed homogeneously in water.