Analysis Of Main Flavor Compounds Composition And Their Differences In Chinese Traditional Vinegar

Chinese traditional vinegar has a long history,not only unique flavor,and has health care functions,including Shanxi extra aged vinegar,Zhenjiang aromatic vinegar,Sichuan bran vinegar and Tianjin Duliu mature vinegar and so on.Due to the differences of raw materials,technology and climate,the flavor of Chinese traditional vinegar has its own characteristics,but the main composition of the flavor is still unclear.In this paper,the use of electronic nose analysis of volatile flavor compounds of Shanxi extra aged vinegar,Zhenjiang aromatic vinegar,Sichuan bran vinegar and Tianjin Duliu mature vinegar.Amino acids,organic acids and carbohydrates were determined by amino acid analyzer and HPLC analysis.Using the principal component analysis method to analyze the main differences in flavor composition,for further optimization of the fermentation process and improving the quality of products to lay the foundation to.The use of electronic nose analysis of volatile flavor compounds of Shanxi extra aged vinegar,Zhenjiang aromatic vinegar,Sichuan bran vinegar and Tianjin Duliu mature vinegar,100 kinds of volatile flavor compounds were detected,among which the contribution of vinegar flavor esters,alcohols,acids,aldehydes and ketones.Through the analysis of the load point,it can be found that the substances with flavor on the difference between Shanxi extra aged vinegar and Zhenjiang aromatic vinegar were n-hexane,crotonaldehyde and acetic acid;And the substances with flavor on the difference between Shanxi extra aged vinegar and Sichuan bran vinegar were acetic acid,furfural,acetonitrile,butyl alcohol and 2-hexenal;And the substances with flavor on the difference between Shanxi extra aged vinegar and Tianjin Duliu mature vinegar were dimethyl sulfide,propionic acid and butyl alcohol.Amino acids,organic acids and carbohydrates were determined for 40 samples by amino acid analyzer and HPLC analysis.For the eight kinds of organic acids,acetic acid and lactic acid were the highest,sum of acetic acid and lactic acid content of more than 90%.Similar amino acid composition of vinegar samples,alanine(14.6%-19.7%),leucine(7.5%-11.3%),aspartic acid(7.1%-10.2%)and valine(7.5%-8.7%),glutamic acid(6.9%-8.8%)were high.Glucose(20.2%-42.9%),fructose(15.3%-33.6%)and mannose(4.9%-27.7%)were high content in traditional vinegar.The PCA was used to select 11 kinds of main compounds from 29 kinds of non-volatile flavor compounds which detected by the instruments above,including 7 kinds of amino acids,2 kinds of organic acids and 2 kinds of carbohydrates.The cluster analysis was used to analysis the relationship of the samples which based on 11 kinds of main non-volatile compounds.Then the similarity values were compared.Finally,the method was established to distinguish the flavor quality of the Chinese traditional vinegar basing on the 8 kinds of compounds,including aspartic acid,alanine,cystine,valine,leucine,proline,mannose and glucose.6 kinds of Chinese traditional vinegar were selected randomly to verify the method.The results showed that the method could be used to classify the Chinese traditional vinegar.In the analysis of the potential characteristics of Chinese traditional vinegar,it was found that the content of organic acids in Shanxi extra aged vinegar,Zhenjiang aromatic vinegar and Tianjin Duliu mature vinegar was moderate,and the ratio of lactic acid to acetic acid was 40-80%,the ratio in Sichuan bran vinegar is more higher(between 300-560%).In the analysis of amino acids,it was found that the ratio of alanine/leucine/aspartic acid/valine/glutamic acid/proline to cystine was between 300-2300%in Shanxi extra aged vinegar,is much higher than Zhenjiang aromatic vinegar and Sichuan bran vinegar ratio(10-300%),can be used as a characteristic indicator of Shanxi extra aged vinegar.