Research on Flavors and Qualities of Optimization Blending Samples of Hunan Raw Dark Teas
In order to study how to obtain the raw materials of dark tea processing with Hunan regional characteristics of mellow and fresh taste,heavy and long-lasting aroma,Zhuyeqi raw dark tea(Z),Taoyuan-daye raw dark tea(T),Huangjincha 1 raw dark tea(H)were obtained by processing the fresh leaves of relative cultivars,and six blending tea samples were obtained by blending these three raw dark tea(Z∶T∶H)with the ratio of 20∶20∶60,20∶60∶20,40∶15∶45,40∶45∶15,60∶10∶30,60∶30∶10.Comparative analysis of their sensory evaluation,taste quality and aroma components was also conducted.The results show that when the proportion of Zhuyeqi raw dark tea was 40％and 60％,the blended teas were mellower and fresher in taste,with heavier and longer-lasting aroma than the original raw tea and the two blends with the proportion of Zhuyeqi raw dark tea of 20％.The tea samples'quality had significant improvement.The results of biochemical analysis show that,when the proportion of Zhuyeqi raw dark tea was 40％and 60％,the contents of water extract and gallic acid were higher,and the taste was mellow and fresh.On this basis,when Taoyuan-daye raw dark tea accounted for a higher percentage of tea,the contents of tea polyphenols,flavonoids,total catechins and caffeine were higher and the taste was mellow.When Huangjincha 1 raw dark tea accounted for a higher percentage of tea,the content of soluble sugar was higher,and the taste was sweeter.A total of 77 volatile components were detected by headspace-solid phase microextraction(HS-SPME)combined with gas chromatography-mass spectrometry(GC-MS).Based on the variable importance in projection(VIP)of the orthogonal partial least squares discriminant analysis method(OPLS-DA),41 components(VIP＞1)were screened out by this experiment,and by further calculating their relative odor activity value(ROAV),13 key differential volatiles such as linalool,L-α-terpineol,cedrol,isopropylidene acetone and crocinaldehyde were identified(VIP＞1,ROAV＞1).When the proportion of Zhuyeqi raw dark tea was 40％and 60％,the high aroma and lasting characteristics were closely related to the high contents of saffron and aldehyde.Adding high proportion of Huangjincha 1 raw dark tea,the contents of D-limonene and linalool oxide(IV)were higher,which gave the floral aroma of the blending samples.
raw dark teaoptimization blendingtaste qualityaroma qualityGC-MS
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维普
