Identification And Recombination Of Characteristic Aroma Compounds Of Jinhua Ham

Jinhua ham is a traditional dry cured meat product in China,with its unique aroma favored by consumers.Aroma is a key factor affecting the overall acceptability of Jinhua ham,which is mainly composed of various volatile organic components(VOCs)produced by lipid decomposition and proteolysis during the ripening process.There are many kinds of VOCs in Jinhua ham,and only a small part of them contribute significantly to its overall aroma.In this project,Jinhua ham was used as the material.Its aroma components were extracted through solvent assisted flavor evaporation method(SAFE).Then the VOCs were separated and identified using gas chromatography mass spectrometry(GC-MS),gas chromatography time-of-flight mass spectrometer(GC-To F/MS),and two-dimensional gas chromatography time-of-flight mass spectrometer(GC×GC-To F/MS).The odor-active components were preliminary identified using gas chromatography-mass spectrometry(GC-MS/O)and analyzed by detection frequency(DF)and aroma extract dilution analysis(AEDA).Odor activity values(OAV)were calculated with contents and threshold of compounds.Combining QDA experiment,compounds with OAV≥1 were added into the matrix for recombination experiment,so as to identify the characteristic aroma components contributing sensory properties in Jinhua ham.This study identified the characteristic aroma components in Jinhua ham and provided a scientific basis for monitoring its quality in food factories.1.Identification of volatile components in Jinhua hamTaking Jinhua ham as the material,the VOCs in Jinhua ham were extracted by SAFE method.The volatiles in Jinhua ham were identified and analyzed by GC-MS,GC-To F/MS and GC×GC-To F/MS.The results showed that 61,158 and 200 volatile components of Jinhua ham were identified by GC-MS,GC-To F/MS and GC×GC-To F/MS,respectively.Among them,46,113 and 130 volatile components were identified in raw samples,respectively.52,129 and 167 volatile components were identified in cooked samples,respectively.Compared with GC-MS,97 VOCs were newly identified in GC-To F/MS,while 138 VOCs were newly identified in GC×GC-To F/MS.Compared with GC-To F/MS,41 VOCs were newly identified in GC×GC-To F/MS.Alcohols(22)were more in the raw samples of Jinhua ham,while ketones(30)were more in the cooked samples of Jinhua ham.2.Analysis of odor active components in Jinhua hamTaking Jinhua ham as the material,the VOCs in Jinhua ham were extracted by SAFE method.The GC-MS/O with DF and AEDA analysis methods were used to analyze the odor active components in Jinhua ham in combination with the identification results of volatile components in Chapter 1.The results showed that a total of 45 odor active components were identified in Jinhua ham samples,of which 32 and 43 were respectively identified in raw and cooked samples.The quantities of the active components were the same but the types were different.The results of DF and AEDA analysis showed that there were 26 important odor active components in the raw and cooked samples of Jinhua ham,including pentanal,hexanal,1-octene-3-one,(E)-2-heptenal,2,6-dimethyl pyrazine,dimethyl trisulfide,nonanal,(E)-2-octenal,methional,2-furylmethanethiol,furfural,butanoic acid,phenylacetaldehyde,3-methyl-butanoic acid,dihydro-5-propyl-2(3H)-furanone,(E,E)-2,4-decadienal,furanone,hexanoic acid,phenylethanol,phenol,dihydro-5-pentyl-2(3H)-furanone,octanoic acid,p-cresol,dihydro-5-hexyl-2(3H)-furanone,nonanoic acid and decanoic acid.3.Confirmation of characteristic aroma components in Jinhua hamBased on the results of the second chapter,odor active components were quantified by external standard methods.OAV was calculated based on threshold and contents of compounds.The aroma profile of Jinhua ham was analyzed by QDA experiment.To identify the characteristic compounds in Jinhua ham,recombination and omission models were prepared through putting volatiles(OAV≥1)into the triglycerides.The results indicated that totally 26 VOCs were quantified in Jinhua ham.OAV results showed that 13 and 14 important odor active components(OAV≥1)were separately identified in raw and cooked Jinhua ham.QDA results showed that there was no significant difference in aroma profile(fire-cured,fermented,putrid,grease,pickled,meaty and year egg)between the raw and cooked samples.Also,cooked samples were less fishy and more meaty than raw samples.Furthermore,9 characteristic aroma components contributing sensory properties were identified in raw and by recombination and omission experiments,including pentanal,(E)-2-heptenal,dimethyl trisulfide,furanone,hexanal,3-methyl-butanoic acid,1-octene-3-one,(E,E)-2,4-decadienal and methional.8 characteristic aroma components were identified in cooked Jinhua ham including 2-furylmethanethiol,(E)-2-heptenal,dimethyl trisulfide,phenylacetaldehyde,furanone,phenylethanol,3-methyl-butanoic acid and methional.