Analysis On Flavor Components And Identification Of Production Technology In Soy Sauce And Vinegars

Soy sauce and vinegar are important seasoning in our daily life.The national standards were promulgated at Sep.1^st 2000.The methods for producting soy sauce and viegar must be truthfully regulated in GB 18186-2000 fermented soy sauce and GB 18187-2000 Fermented Vinegar,that was the high-salt liquid-state fermented soy sauce or the low-salt solid-state fermented soy sauces,the solid-state fermented vinegar or the liquid-state fermented vinegar.But there were no standard techniques in soy sauce and vinegar production and the corresponding national quality standards were simple.Therefore,counterfeit products were prevalent.The flavor component was one of the important indicators to evaluate the quality of some products.Thus,flavor compounds in soy sauce and vinegars were analyzed in the present study by head space-solid phase microextraction coupled with gas chromatogragh(HS-SPME-GC) to assess the quality of products.In this paper, optimization of determination condition for flavor compounds in Soy Sauce and vinegars and were determined qualitatively and quantitatively by means of HS-SPME-GC,and then the data was processed using principal component analysis and cluster analysis,the main flavor components of the soy sauce and vinegars were determined and the quality indexs of different kinds making processes were identified. The main results were as follows.1.A method for detection of flavor compounds in soy sauce by SPME-GC had been developed.The analysis parameters of SPME fiber coating,extraction time, sample temperature,content of sodium chloride,desorption time had been optimized. Finally,The optimized method was determined:A 10-mL soy sauce was placed into a 20-mL vial and saturated with lg sodium chloride.The sample was extracted using 85μmPA fiber for 30 min at 40℃,then the volatiles were desorbed from the fiber at temperature of 230℃for 3min.Consequently,52 components were identified by means of GC-MS/GC,20 of which were quantified.The identified compounds were 11 alcohols,11 acids,6 carbonyls,12 esters,4 phenols,8 other compounds.The recoveries was between 91.2%and 106.7%.The experiment of reproducibility of relative contents was good and relative standard deviations(RSD) was less than 10%.2.A method for detection of flavor compounds in vinegars by SPME-GC had been developed.The analysis parameters of dilution multiple,extraction time,sample temperature,content of sodium chloride,desorption time had been optimized.Finally, the optimized method was determined:The vinegar was diluted 20 times with deionized water and then the 10mL diluted vinegar was placed into a 20-mL vial and saturated with 3g sodium chloride.The sample was extracted using 85μmPA fiber for 45 min at 40℃,then the volatiles were desorbed from the fiber at 230℃for 3min. Consequently,59 components were identified by means of GC-MS/GC,24 of which were quantified.The identified compounds were 14 alcohols,14 acids,12 esters,10 carbonyls,3 phenols,3 pyrazines,3 other compounds.The recoveries was at the range from 88.3%to 100.9%.The experiment of reproducibility of relative contents was good and relative standard deviations(RSD) was less than 10%.3.The results of principal component analysis for the data of the soy sauces indicated that the accumulative contribution rate of the first five principal components to total variation accounted for 82.373%＞80%,maintaining most of information of original data.they consisted of alcohol,ethyl acetate,ethyl lactate,butanol,isoamyl alcohol,3-(methylthio)-1-propyl acetate,furfuryl alcohol,β-phenylethyl alcohol, 4-ethyl guaiacol and 2-acetyl pyrrole in soy sauce.4.The results of principal component analysis for the data of vinegars indicated that the accumulative contribution rate of the first four principal components to total variation accounted for 81.253%＞80%,maintaining most of information of original data.they consisted of diacetyl,isovaleraldehyde,4-ethyl guaiacol,ethyl lactate,β-phenylethyl alcohol,isoamyl acetate,isobutanol,butyrate,butanol and pentanoic acid in vinegars.5.The results of cluster analysis for the data of the soy sauces indicated that the content of alcohol,ethyl acetate,ethyl lactate,butanol,isoamyl alcohol,β-phenylethyl alcohol and 4-ethyl guaiacol were high content in the high-salt liquid-state fermented soy sauce,the maximum content was 33600mg/L,23.3mg/L,36.2mg/L,8.1mg/L and 2.8mg/L respectively;However,the content of acetic acid and 2-acetyl pyrrole was high content in the low-salt solid-state fermented soy sauces,the maximum contents was 2380.3mg/L and 62.9mg/L respectively;There were more than 50 kinds of flavor components detected in the high-salt liquid-state fermented soy sauce,but only approximately 40 kinds of flavor components detected in the low-salt solid-state fermented soy sauces.The results also showed that there were very great difference for the two kinds of the high-salt liquid-state fermented soy sauce process in the content of the flavor components,except for furfuryl alcohol and 2-acetyl pyrrole.There were lower contents of the flavor compounds in the natural fermented soy sauce than those in the high-salt liquid-state fermented processing adoptd by japanese.6.The results of cluster analysis for the data of vinegars indicated that the content of isovaleraldehyde,diacetyl,n-propanol,3-hydroxy-2-butanone,ethyl lactate, furfuryl alcohol,4-ethyl guaiacol and 4-ethylphenol was high content in the solid-state fermented vinegar,the maximum contents was 3.9mg/L,208.2rag/L, 54.9mg/L,2935.7mg/L,19.7mg/L,252.1mg/L,6.8mg/L and 24.3 mg/L respectively. However,the content of them were lower content in the liquid-state fermented vinegars.The content of diacetyl was at the range from 9.7mg/L to 23.3 mg/L,the content of 3-hydroxy-2-butanone was at the range from 200.6mg/L to 792.6 mg/L; Except for 3-hydroxy-2-butanone,the other above flavor compounds were not detected in the blended vinegars;There were more than 50 kinds of flavor components detected in the solid-state fermented vinegars,more than 30 kinds of aroma components detected in the liquid-state fermented vinegar,only approximately 20 kinds of flavor components detected in the blended vinegars.7.The results of principal component analysis and cluster analysis indicated that profiles of flavor components of soy sauce or vinegar depended on their fermentation processes.The difference was reflected in the type and content of flavor compounds. Thus,the fermentation processes of soy sauce or vinegars could be deduced according to the type and content of flavor compounds in their products.