桑叶茯砖茶总黄酮提取工艺优化及抗氧化活性  

Optimization of the extraction process of total flavonoids from mulberry leaves Fu brick tea and their antioxidant activities

作　　者：曾桥 韦承伯 韩国锋 韦文龙 蒋佳琪 白思蕊 ZENG Qiao;WEI Cheng-bo;HAN Guo-feng;WEI Wen-long;JIANG Jia-qi;BAI Si-rui(School of Food and Biological Engineering, Shaanxi University of Science ＆ Technology, Xi＇an 710021;College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science ＆ Technology, Xi＇an 710021;Shaanxi Research Institute of Agricultural Products Processing Technology, Xi＇an 710021;Shaanxi PuDao Fu brick tea Limited by Share Ltd., Xianyang 713700)

机构地区：[1]陕西科技大学食品与生物工程学院,西安710021 [2]陕西科技大学轻工科学与工程学院,西安710021 [3]陕西农产品加工技术研究院,西安710021 [4]陕西朴道茯茶股份有限公司,咸阳713700

出　　处：《食品科技》2018年第6期221-230,共10页Food Science and Technology

基　　金：2017年国家级大学生创新创业训练计划项目(20171070803);咸阳市科技计划项目(2017K02-108)

摘　　要：目的:优化桑叶茯砖茶总黄酮的乙醇提取工艺,并对其体外抗氧化活性进行研究。方法:通过单因素实验考察了乙醇浓度、液料比、提取时间、提取温度等对桑叶茯砖茶总黄酮得率的影响,在此基础上,采用响应面分析法优化提取工艺。以DPPH自由基清除率、.OH清除率、ABTS^+清除率和还原力等为指标,考察桑叶茯砖茶总黄酮的体外抗氧化活性。结果:最佳提取工艺条件为乙醇浓度为33%、液料比为25 mL/g、提取时间为2.3 h、提取温度为90℃,在该最佳条件下,桑叶茯砖茶总黄酮得率为2.37%。抗氧化实验表明,24μg/mL桑叶茯砖茶总黄酮对DPPH自由基清除率达89.8%,与Vc相当,ABTS^+的清除率为99.8%,清除效果较Vc好;0.28mg/mL桑叶茯砖茶总黄酮对.OH清除率达79.7%,而相同浓度Vc对.OH清除率为28.8%,显著低于桑叶茯砖茶总黄酮,0.28 mg/mL桑叶茯砖茶总黄酮还原力为1.263,和Vc接近。结论:该优选提取工艺稳定可行,桑叶茯砖茶总黄酮具有较强的抗氧化活性,为桑叶茯砖茶的开发和应用提供了依据。Objective： To optimize ethanol extraction process of total flavonoids from mulberry leaves Fu brick tea and investigate its invitro antioxidant activity. Method： The effects of ethanol concentration, liquid-solid ratio, extraction time and extraction temperature on the yield of total flavonoids were investigated by single factor experiments. Response surface methodology was used to optimize the extraction process. The antioxidant activities were examined from the aspects of scavenging rate of DPPH, hydroxyl free radicals, ABTS~＋ and reducing power. Results： The optimum extraction process conditions were as follows： ethanol concentration was 33%, ratio of liquid to solid was 25 mL/g, extraction time was 2.3 h and extraction temperature was 90 ℃. Under the best condition, the yield of total flavonoids from mulberry leaves Fu brick tea was 2.37%. When total flavonoids concentration of the mulberry leaves Fu brick tea was 24 μg/mL, the rate of scavenging DPPH radicals was 89.8%, equivalent to Vc, and ABTS~＋scavenging rate was 99.8%, which was better than that of Vc. When total flavonoids concentration of the mulberry leaves Fu brick tea was 0.28 mg/mL, the rate of scavenging.OH radicals was 79.7%, while the same concentration of Vc on the.OH scavenging rate was 28.8%, significantly lower than that of mulberry leaves Fu brick tea, and the reducing power reached to 1.263 closing to Vc. Conclusion： The optimum extraction process is stable and feasible, the mulberry leaves Fu brick tea total flavonoids shows a relatively high antioxidant activity. It provides reference for development and utilization of mulberry leaves Fu brick tea.

关 键 词：桑叶 茯砖茶 总黄酮 响应面法 抗氧化活性 

分 类 号：TS272[农业科学—茶叶生产加工]