基于HS-SPME-GC-MS分析5种甜(花)蜜香型红茶品质及关键香气成分OA

[Objective]This study aimed to investigate the quality and key aroma components of black teas of sweet(floral)honey aroma type,providing theoretical basis for selecting new germplasms of sweet(floral)honey aroma type in Guangxi.[Method]Sensory evaluation,high performance liquid chromatography(HPLC),headspace solid-phase microextraction-gas chromatography-mass spectrometry(HS-SPME-GC-MS)combined with odor activity value(OAV)were adopted to systematically analyze the quality and key aroma components of two black teas of sweet honey aroma type(TM-GZ,TM-LS3)and three black teas of floral honey aroma type(HM-LS2,HM-LS3,HM-TEJ),with Qianmei 809(QM-809)as the control.[Result]Samples of the five black teas of sweet(floral)honey aroma type presented bright red(red)infusion,pronounced sweet(floral)honey aroma,and sweet mellow(rich mellow)taste,with their total scores of sensory evaluation all higher than the control.The quality component determination results showed that,the contents of water extracts,tea polyphenol,free amino acid,caffeine,gallic acid,theobromine,and total catechin con-tent in samples of the six black teas were 38.50%to 42.77%,12.29%to 20.09%,2.94%to 5.32%,48.53 to 66.93 mg/g,2.72 to 5.74 mg/g,1.44 to 3.31 mg/g,and 13.90 to 33.36 mg/g respectively.Ester catechin accounted for 64.20%-78.12%of the total catechin content,and the contents of catechin(C),gallocatechin gallate(GCG),and epicatechin gallate(ECG),as well as the total contents of ester catechin,and total catechin in the five black teas of sweet(floral)honey aroma type were all significantly higher than those in the control(P<0.05).A total of 86 volatile compounds were identi-fied using HS-SPME-GC-MS,including 26 alcohol compounds,19 aldehyde compounds,16 ester compounds,13 ke-tone compounds,6 terpene compounds,3 oxygen-containing heterocycle compounds,1 phenol compound,and 2 other compounds.Among them,62,64,64,62,66,and 51 volatile compounds were detected in QM-809,TM-GZ,TM-LS3,HM-LS2,HM-LS3,and HM-TEJ respectively.The total volatile compound content was in the order of HM-LS2>HM-LS3>TM-GZ>QM-809>TM-LS3>HM-TEJ.Based on the standard of variable importance in projection(VIP)≥1 and OAV>1,12 key aroma compounds were screened,including 7 alcohol compounds[(Z)-3-hexen-1-ol,trans-linalool oxide(furanoid),linalool,1,5,7-octatrien-3-ol,3,7-dimethyl-,phenylethyl alcohol,geraniol,(E)-nerolidol],2 alde-hyde compounds(2-hexenal,phenylacetaldehyde),2 terpene compounds(α-myrcene,α-ocimene)and 1 ester com-pound(methyl salicylate),which mainly contributed to floral,honey,fruity,sweet,and green aromas.The OAVs of α-myrcene,benzeneacetaldehyde,trans-linalool oxide(furanoid),linalool,methyl salicylate,and geraniol were higher than 1 in the samples of the six black teas.[Conclusion]α-Myrcene,phenylacetaldehyde,trans-linalool oxide(fura-noid),linalool,methyl salicylate,and geraniol are the key contributors to black tea aroma.Among the five black teas of sweet(floral)honey aroma type,HM-LS2 and HM-LS3 show better aroma quality and greater development potential.