基于茶汤色差和pH的乌龙茶产品判别  

Oolong tea products discrimination based on the chromaticity and pH of the liquor

作　　者：董青华[1,2] 孙威江[1] 张孔碌 罗星火 吴全金[1] 

机构地区：[1]福建农林大学园艺学院,福建福州350002 [2]福州市华茗茶业研究所,福建福州350001 [3]福建茶叶进出口有限责任公司,福建福州350014

出　　处：《福建农林大学学报（自然科学版）》2012年第4期470-475,共6页Journal of Fujian Agriculture and Forestry University:Natural Science Edition

基　　金："十二五"农村领域国家科技支撑计划项目(2011BAD01B01-3);国家国际科技合作项目(2010DFB33030-4);福建省质量技术监督局标准化项目(2011708)

摘　　要：以福建闽南、闽北和广东乌龙茶为样本,开展基于茶汤色差和pH的乌龙茶产品判别模型分析.结果表明:(1)在评饮温度范围内,温度对乌龙茶茶汤的色差和pH均无显著影响.(2)(45±2)℃下,随着冲泡次数的增多,茶汤明亮度表征量(L)升高,第1泡茶汤的L显著低于第3泡;3泡茶汤间红绿度(a)和黄蓝度(b)的变化均不显著;3泡茶汤色差的衍生值色相(b/a)、色调彩度(Cab)和色彩饱和度(Sab)均无显著差异,色相角(Hab)差异达显著水平;3泡茶汤间的pH存在显著差异.(3)(45±2)℃下,以第1泡茶汤的色差和pH为自变量,采用逐步判别分析法对茶样进行产地、品种、级别和品类鉴别,建立判别模型,得到正判率达92%的产地判别函数3条,正判率均达100%的肉桂和凤凰单丛生产商判别函数2条.With Guangdong, southern and northern Fujian Oolong tea as samples, the model of products discrimination based on the chromaticity and pH were studied. The results were as follows. （ 1 ） Within the scope of assessment drinking, temperature had no significant effect on the chromaticity and pH of Oolong tea. （2）At （45 ±2） ℃, with the increasing of hrewing times, the indicator of light and dark （L） increased, which is an indicator of chromaticity; it was significantly lower in first brewing than in third brewing. Among the 3 times of brewing, the change of red-green （a） and yellow-blue （b） degree in the tea liquor was not significant; there was no significant difference in the derivative value of the chromaticity hue （b/a）, hue chmma value （Cab）, and color saturation value （Sab） ; whih the pH and hue angle （Hab） had significant difference. （3） At （45 ± 2） ℃, setting the chromaticity and pH of first brewing liquor as independent variable, using stepwise discriminant analysis to classify the sample area, variety, grade and category, the discrimination medels were extablished. The accuracy of three discrimination functions for producing area reached 92%, and the accuracy of two discrimination functions for producers of Rougui and Fenghuang Dancong was 100%.

关 键 词：乌龙茶茶汤 色差 PH 判别分析 

分 类 号：S571.1[农业科学—茶叶生产加工]