Study On The Mapping And Correlation Evaluation Of Sensory And Chemical Components Of Tea Aroma And Taste Based On Sensomics

In this paper,we systematically carried out the work of"Study on the mapping and correlation evaluation of sensory and chemical components of tea aroma and taste based on sensomics".It means,using the idea and method of"-omics"research for reference,the aroma and taste of tea were evaluated by"multi-factor"sensory evaluation and"multi-component"evaluation respectively,and the mapping relationship between sensory quality factors and component content and proportion of tea aroma and taste was established.Through the correlation evaluation,the experiment explained the characteristic mode of"aroma and taste"of tea,and constructed the"flavor profile"of tea aroma and taste.The purpose of this study is to enrich the relevant contents of tea flavor chemistry,improve the sensory evaluation method of tea,establish the sensory factor"quantitative evaluation method",discuss the visual representation of tea"flavor profile",and provide the technical basis for the means and methods of tea"flavor characteristic evaluation","consumption preference"investigation and evaluation,and tea flavor design.The main results are as follows:(1)Through a variety of analysis methods combined with the traditional sensory evaluation of tea,a factor level sensory evaluation system and a large number of sample quantitative sensory evaluation method of tea were established.Through the statistical method of terms frequency,the ability of terms to describe 5 sensory evaluation projects(shape(38.6%)>waste tea(24.9%)>aroma(14.0%)?taste(13.3%)>infusion color(9.2%))and 20 evaluation factors(such as"color","tenderness"and"aroma type"were the three factors with the strongest descriptive ability(9.9-10.6%),and"persistence"factors with the weakest descriptive ability(0.7%))was clarified,moreover,a table of the differences in the distribution of terms of different grades of tea samples was constructed,this is of great significance to the standardized classification of terms and the quantitative evaluation of tea based on terms.According to the membership function matrix(U_superior=[0.7,1],U_good=[0.55,0.7],U_middle=[0,0.55]),all tea samples were divided into three grades:superior(19.8%-20.7%),good(41.4%-42.9%)and medium(36.9%-38.7%),which provided a new method for quantitative evaluation of tea based on scores.(2)The types and characteristics of aroma and taste of tea were evaluated,the"flavor profile"was constructed,and the"flavor mode"and its"visual"representation were discussed.According to the sensory scores of tea samples,five evaluation items were classified into three categories,four aroma factors into two categories,four taste factors into three categories,and the correlation evaluation was carried out.According to the weight of the items and factors,the"flavor contour map"was constructed by radar map and Nightingale rose map respectively,and the"taste pattern"was visualized.(3)The regression equations of 14 aroma sub factors were fitted by stepwise linear regression(for example,the fitting equation of green tea"tender aroma"was S_{(tender aroma)}=0.038×X₁+0.0001×X₂+0.003×X₃,X₁=OAV(E,E-2,4-heptanedialdehyde,X₂=OAV(?-ionone),X₃=OAV(n-hexanal),R²=1.000,P<0.001;the"fresh aroma"of jasmine tea was S_(freshness)=1.111×X₁-0.171×X₂+0.0001×X₃,X₁=OAV(laurene),X₂=OAV(geraniol),X₃=OAV(Neroli alcohol),R²=1.000,P<0.001,etc.),which meaned the law of aroma presentation was revealed,and the linear correlation between 34 main aroma contributing components OAV and the aroma intensity of corresponding aroma sub factors was established.(4)The regression equations of 5 taste sub factors were fitted by stepwise linear regression(for example,the fitting equation of"astringency"was S_{(astringency)}=0.998×X₁+0.003×X₂+0.387×X₃,X₁=TAV(apigenin-8-o-glucoside),X₂=TAV(quercetin-3-o-glucoside),X₃=TAV(vitexin-2-o-rhamnoside),R²=0.981,P=0.042;"strongness"was S_{(concentration)}=0.499×X₁+0.242×X₂,X₁=TAV(caffeine),X₂=TAV(myricetin-3-o-galactoside),R²=0.981,P=0.003,etc.),which meaned the law of taste presentation was revealed,and the linear correlation between 14 main taste contributing components TAV and the corresponding taste sub factors was established.(5)The results of aroma(taste)analysis of tea were verified by aroma(taste)reconstitution test,which proved that the above OAV/TAV evaluation results could basically analyze tea aroma(taste).The aroma(taste)reconstitution solution of 8 tea samples were constructed by 50 aroma components monomers with OAV>1 and 5representative taste components monomers with TAV>1,and the results showed that the aroma reconstitution solution had the same characteristics as the original tea(S_deviation=-0.78-+0.37),and the reduction degree of"fresh"(S_deviation=-0.12-+0.25),"astringency"(S_deviation=+0.02-+0.22)and"bitter"(S_deviation=0.00-+0.08)was also higher.(6)Through GC-O detection,30 potential aroma contributing components(such as cis-3-hexenoic acid cis-3-hexene ester,?-Muurolene,etc.)of tea were further identified,12 of which(such as D-Macrophylle(fatty,fruity,woody),trans-?-bergamotene(woody,fatty),?-copaene(woody,fruity),etc.)were first reported to be aroma characteristcs.