A central composite design(CCD),with three variables and three levels,was used to optimize withering and fermentation processing during manufacture of Congou black tea of Sichuan.The three independent variables were w...A central composite design(CCD),with three variables and three levels,was used to optimize withering and fermentation processing during manufacture of Congou black tea of Sichuan.The three independent variables were withering time,fermentation time and fermentation temperature.Each factor was set by three levels.The responses were predicted by analysis of the regression equation.In the study,the models of regression equation were significant by the analysis of variance(ANOVA).The second-order response surface figures were showed that interaction term is correlated with the response.Optimal process parameters for the maximum of TF and TR formation were obtained at withering time of 12 hours,fermentation time of 2 hours,and fermentation temperature of 30℃.The predictions of TF and TR formation were 0.52% and 3.98%.The results obtained in this study showed that the CCD and Response Surface Methodology(RSM) could be an effective tool to optimize the process parameters of Congou black tea manufacture.展开更多
为了解不同茶树品种制作的芽型工夫红茶品质差异,采用高效液相色谱技术、固相微萃取-气相色谱-质谱联用(SPME-GC-MS)技术、定量描述性分析和化学计量学对10个茶树品种芽型工夫红茶的特征滋味物质和特征香气成分进行分析。定量描述性分...为了解不同茶树品种制作的芽型工夫红茶品质差异,采用高效液相色谱技术、固相微萃取-气相色谱-质谱联用(SPME-GC-MS)技术、定量描述性分析和化学计量学对10个茶树品种芽型工夫红茶的特征滋味物质和特征香气成分进行分析。定量描述性分析结果表明,10个茶树品种芽型工夫红茶的整体香气以甜香、花香为主,滋味以甜醇、浓厚为主。不同样品中检测的16种内含成分(非挥发性成分)存在一定的差异,平均变异系数为21.63%,其中茶黄素的差异最大;在10个茶树品种红茶中共检测出49种挥发性物质,其中质量分数最高的挥发性物质类型为醇类化合物,其次为酯类化合物,酮类化合物质量分数最低,其中香叶醇质量分数最高;正交偏最小二乘判别分析(orthogonal partial least squares-discriminant analysis,OPLS-DA)能将‘金牡丹‘’福云7号’与其他茶树品种红茶区分开,且筛选出12种与芽型工夫红茶茶树品种密切相关的标志差异物。相关性分析结果表明,咖啡碱和茶多酚与回甘呈显著正相关,咖啡碱、可可碱与醇度呈显著正相关,香叶醇、顺-α,α-5-三甲基-5-乙烯基四氢化呋喃-2-甲醇、水杨酸甲酯、芳樟醇与花果香呈正相关。该研究为芽型工夫红茶的生产加工和品质提升提供了理论依据。展开更多
为探究中国工夫红茶主要品质成分含量特征,建立茶汤滋味品质综合评价方法。对17个国内主产茶区工夫红茶的多酚类、氨基酸、茶色素类、香气组分等品质指标进行测定,运用主成分分析、聚类分析和偏最小二乘-判别分析(partial least squares...为探究中国工夫红茶主要品质成分含量特征,建立茶汤滋味品质综合评价方法。对17个国内主产茶区工夫红茶的多酚类、氨基酸、茶色素类、香气组分等品质指标进行测定,运用主成分分析、聚类分析和偏最小二乘-判别分析(partial least squares-discrimination analysis,PLS-DA)对其品质进行综合评价。结果表明:不同产区工夫红茶的品质成分组成与含量存在明显差异,多酚类及其氧化产物是主要的品质成分,茶黄素和茶红素之和与茶褐素的比值为1.05~1.12,是其滋味鲜醇、汤色红亮的物质基础;英红、海红、信阳红、宜红、越红、黔红和祁红的可溶性糖质量分数均高于4%,是其茶汤甜醇滋味的重要物质基础;黄酮在大叶种红茶(滇红、英红和海红)中的质量分数较高且大于2.7%。醇类和醛类是主要的香气化合物,尤其是呈现甜香、花香的萜烯醇含量较高。利用主成分分析法建立滋味品质评价模型,该预测模型对红茶滋味品质评价结果与感官审评结果较为相似,存在极显著相关(P<0.01),相关系数为0.735;茶黄素和茶多酚含量是进行工夫红茶品质分析的重要指标。系统聚类分析显示闽红自为一类,滇红、英红和海红等大叶种红茶聚为一类,其他中小叶种红茶聚为一类。PLS-DA可将2类不同品种工夫红茶明显区分,并获得8种差异性指标,尤其是芳樟醇、香叶醇和己醛等,可作为区分大叶种和中小叶种工夫红茶的指标物质。该研究丰富了工夫红茶风味品质的基础理论,同时为红茶品质的科学评价提供新的思路和方法。展开更多
基金Supported by the Pillar Program of the Ministry of Science and Technology of China 2012BAF07B05
文摘A central composite design(CCD),with three variables and three levels,was used to optimize withering and fermentation processing during manufacture of Congou black tea of Sichuan.The three independent variables were withering time,fermentation time and fermentation temperature.Each factor was set by three levels.The responses were predicted by analysis of the regression equation.In the study,the models of regression equation were significant by the analysis of variance(ANOVA).The second-order response surface figures were showed that interaction term is correlated with the response.Optimal process parameters for the maximum of TF and TR formation were obtained at withering time of 12 hours,fermentation time of 2 hours,and fermentation temperature of 30℃.The predictions of TF and TR formation were 0.52% and 3.98%.The results obtained in this study showed that the CCD and Response Surface Methodology(RSM) could be an effective tool to optimize the process parameters of Congou black tea manufacture.
文摘为了解不同茶树品种制作的芽型工夫红茶品质差异,采用高效液相色谱技术、固相微萃取-气相色谱-质谱联用(SPME-GC-MS)技术、定量描述性分析和化学计量学对10个茶树品种芽型工夫红茶的特征滋味物质和特征香气成分进行分析。定量描述性分析结果表明,10个茶树品种芽型工夫红茶的整体香气以甜香、花香为主,滋味以甜醇、浓厚为主。不同样品中检测的16种内含成分(非挥发性成分)存在一定的差异,平均变异系数为21.63%,其中茶黄素的差异最大;在10个茶树品种红茶中共检测出49种挥发性物质,其中质量分数最高的挥发性物质类型为醇类化合物,其次为酯类化合物,酮类化合物质量分数最低,其中香叶醇质量分数最高;正交偏最小二乘判别分析(orthogonal partial least squares-discriminant analysis,OPLS-DA)能将‘金牡丹‘’福云7号’与其他茶树品种红茶区分开,且筛选出12种与芽型工夫红茶茶树品种密切相关的标志差异物。相关性分析结果表明,咖啡碱和茶多酚与回甘呈显著正相关,咖啡碱、可可碱与醇度呈显著正相关,香叶醇、顺-α,α-5-三甲基-5-乙烯基四氢化呋喃-2-甲醇、水杨酸甲酯、芳樟醇与花果香呈正相关。该研究为芽型工夫红茶的生产加工和品质提升提供了理论依据。
文摘为探究中国工夫红茶主要品质成分含量特征,建立茶汤滋味品质综合评价方法。对17个国内主产茶区工夫红茶的多酚类、氨基酸、茶色素类、香气组分等品质指标进行测定,运用主成分分析、聚类分析和偏最小二乘-判别分析(partial least squares-discrimination analysis,PLS-DA)对其品质进行综合评价。结果表明:不同产区工夫红茶的品质成分组成与含量存在明显差异,多酚类及其氧化产物是主要的品质成分,茶黄素和茶红素之和与茶褐素的比值为1.05~1.12,是其滋味鲜醇、汤色红亮的物质基础;英红、海红、信阳红、宜红、越红、黔红和祁红的可溶性糖质量分数均高于4%,是其茶汤甜醇滋味的重要物质基础;黄酮在大叶种红茶(滇红、英红和海红)中的质量分数较高且大于2.7%。醇类和醛类是主要的香气化合物,尤其是呈现甜香、花香的萜烯醇含量较高。利用主成分分析法建立滋味品质评价模型,该预测模型对红茶滋味品质评价结果与感官审评结果较为相似,存在极显著相关(P<0.01),相关系数为0.735;茶黄素和茶多酚含量是进行工夫红茶品质分析的重要指标。系统聚类分析显示闽红自为一类,滇红、英红和海红等大叶种红茶聚为一类,其他中小叶种红茶聚为一类。PLS-DA可将2类不同品种工夫红茶明显区分,并获得8种差异性指标,尤其是芳樟醇、香叶醇和己醛等,可作为区分大叶种和中小叶种工夫红茶的指标物质。该研究丰富了工夫红茶风味品质的基础理论,同时为红茶品质的科学评价提供新的思路和方法。
