Study On The Fresh And Brisk Taste And Its Discriminant Model Of Green Tea

Green tea is one of the largest tea production in China, taste is the most important qualitycharacteristics of green tea, and its also decided to consumer acceptance and one of the importantindicators of product value, the fresh and brisk taste is an important feature of the taste of the beverage.Therefore, study on fresh and brisk taste of chemical composition is importance in green tea. Thispaper chosen the typical samples of green tea, Tea samples were classificated with the sensoryevaluation results and compared with the electronic tongue technology, and examined the mainchemical composition—amino acid, organic acid, catechins, caffeine and free sugar were qualitative andquantitative analysed in tea beverage, explored the key to the chemical constituents of fresh and brisktaste. Furthermore, the preliminary discriminant model of green tea fresh and brisk taste has beenestablished. The main results were listed as follows:(1)The classification of green tea fresh and brisk taste and sensory evaluation experiments werediscussed, according to the different taste, the green tea samples were divided into fresh and brisk tastetype, middle taste type, none-fresh and brisk taste type by sensory evaluation, Furthermore, theelectronic tongue of sensor and sensory evaluation of PLS fitting model was established, the correlationcoefficient reached0.9223. And different taste type of green tea beverage were distinguished byelectronic tongue of DFA.(2)The chemical composition of the tea beverage was determined, and the quantitativecharacteristic of the main chemical content in green tea beverage were analysed, and most of the singlechemical composition under its threshold, whereas glutamic acid, EGCG, EGC, caffeine, gallic acidconcentration were higher than its threshold in the tea beverage.(3)LSD multiple comparison found that glutamate, glycine, serine, alanine, proline, methionine,umami amino acid, sweet taste amino acid, total amino acid, lactic acid, succinic acid, citric acid, totalorganic acid were the key to the chemical constituents fresh and brisk taste in green tea beverage(p <0.05).(4)In order to distinguish characteristics of aroma types of green tea and establish mathematicalmodel for judgment of fresh and bristk taste types. The single factor analysis of variance, mult-variablelinear return analysis, principal component analysis were used for data analysis and model construction,the results of discriminant analysis indicated that11chemical components (serine acid, glutamic acidglycine acid, methionine acid, arginine acid, alanine acid, proline acid, theanine, EGCG, lactic acid,succinic acid) were used in the discriminant function and found discriminant model. The recognitionaccuracy for the training sample set was100%. Cross-validation method were82.8%. The other11samples were predicted using this model, the accuracy of predicted samples about3kinds taste typeswere90.9%. In conclusion, the discrimination method had its own advantage and could be used to identify taste type of green tea accurately.