BaCl_2和Ca(CH_3COO)_2沉淀法定量分析普洱茶茶褐素官能团  

Quantitative Determination of Functional Groups in Theabrownine from Pu-erh Tea Based on BaCl_2 and Ca(CH_3COO)_2 Precipitation Methods

作　　者：秦谊[1] 龚加顺[2] 张惠芬[1] 周红杰[3] 何静[1] 李宝才[1] 

机构地区：[1]昆明理工大学生命科学与技术学院,云南昆明650224 [2]云南农业大学食品科技学院,云南昆明650201 [3]云南农业大学龙润普洱茶学院,云南昆明650201

出　　处：《林产化学与工业》2010年第6期107-112,共6页Chemistry and Industry of Forest Products

基　　金：国家自然科学基金资助项目(30760152)

摘　　要：将有机官能团分析方法BaCl2法和Ca（CH3COO）2法应用于茶褐素官能团的定量分析,并建立了适合茶褐素官能团分析的操作方法,用于测定茶褐素中的总酸性基、羧基和酚羟基的含量。通过方法学考察,确定了BaCl2法和Ca（CH3COO）2法的优化实验条件：BaCl2法的称样量为0.02-0.08 g,沉淀时间30~60 min,BaCl2溶液浓度0.75 mol/L;Ca（CH3COO）2法的称样量为0.05-0.1 g,沉淀时间20 min,Ca（CH3COO）2溶液浓度1 mol/L。从普洱熟沱提取的茶褐素总酸性基为7.780 mmol/g,其中酚羟基为5.805 mmol/g,羧基为1.975 mmol/g,表明酚羟基是茶褐素中最主要的酸性基团。本研究建立的分析方法操作简单,所得结果精密度高,准确度好,非常适用于茶褐素中官能团的定量分析。The functional groups analysis methods,namely barium chloride（BaCl2） method and calcium acetate（Ca（CH3COO）2）method,were used to determine the content of functional groups of theabrownine for the first time,and suitable operating methods were established to determine the contents of total acidic groups,carboxyl groups and phenolic hydroxyl groups.The optimum conditions of determination were obtained as follows： for the BaCl2 method,sample weight 0.02-0.08 g,precipitation time 30-60 min,concentration of BaCl2 0.75 mol/L;for the Ca（CH3COO）2 method,sample weight 0.05-0.1 g,precipitation time 20 min,concentration of Ca（CH3COO）2 1 mol/L.The total acidic groups content of theabrownine from Pu-erh tea is 7.780 mmol/g,of which phenolic hydroxyl groups is 5.805 mmol/g and carboxyl groups is 1.975 mmol/g.The results indicate that phenol hydroxyl groups are the most important acidic groups in theabrownine.Both BaCl2 method and Ca（CH3COO）2 method are simple and require neither elaborate equipment nor special skills.With satisfactory results,these methods appear to be suitable for use in the routine analysis of functional groups in theabrownine.

关 键 词：普洱茶 茶褐素 官能团分析 氯化钡法 乙酸钙法 

分 类 号：TQ351[化学工程]