Analysis And Evaluation Of Volatile Flavor Substances In Koumiss And Milk Wine In Inner Mongolia

This paper takes koumiss and milk wine in Inner Mongolia as the research objects.Using electronic nose and gas chromatography-mass spectrometry(GC-MS)to detect and analysis its flavor substances in qualitative and quantitative research.And cluster analysis and judge analysis the results of the two test methods by principal component analysis(PCA)and partial least squares-discriminant analysis(PLS-DA)models in multivariate statistical analysis.The research results are as follows:(1)The best measurement time and data points of volatile flavor substances in koumiss,fermented milk wine and distilled milk wine by electronic nose are 120s and 100s respectively.According to the W5S,W1S,W1W,W2S,and W2W sensor data with the highest response intensity,the flavor substances that make the electronic nose sensitive in koumiss and milk wine are nitrogen oxides,alkanes,sulfides,alcohols,aldehydes,ketones and aromatics.The overall response strength of koumiss is lower than that of milk wine,which may be higher the content and flavor contribution of several types of substances are lower than that of milk wine.(2)The results of the comparison test of the three pretreatment conditions of the liquid-liquid extraction(LLE),solid phase extraction(SPE)and headspace solid phase microextraction(HP-SPME)of the tested samples,the HP-SPME treatment method is the most Excellent,with the addition of 3-octanol at a concentration of 30?g/mL as an internal standard,through qualitative and quantitative analysis,the results show that 51 kinds,67 kinds and 68 kinds flavor substances were detected in koumiss,fermented milk wine and distilled milk wine.The flavoring materials of koumiss are mainly based on acids and esters,with an average proportion of more than 98%;there are relatively many alcohols,aromatics and nitrogen-containing substances in milk wine samples,and their contents account for about 6%,About 3%and 5%account for about 8%,6%and 1%of distilled milk wine,respectively.These types of flavor substances may have more influence on the flavor of milk wine.The distribution of acids,esters and aromatics in koumiss and milk wine samples is inconsistent.In koumiss,fatty acids are the main ingredients,and lactone and vanillin are the main ingredients in the milk wine.(3)Using PCA and PLS-DA models in the SIMCA-P data processing software to analyze the electronic nose data and GC-MS data respectively,and combine the SPSS software to perform a significant T test on the GC-MS results.The results of the two fitted models show that,three kinds samples clustering obviously,the fitting degree reaches 0.992,0.991,0.650 and 0.751respectively.The over-fitting verification results are good,which shows that the two models can achieve better clustering analysis on the three samples.By analyzing the four abnormal data points N1,N3,F9 and Z1,the accuracy of the model is verified.Finally,using the VIP value>1 and the significance T test p<0.05 as the standard to screen out 17 different flavor substances of koumiss and fermented milk wine,mainly 8 fatty acids and 7 ethyl esters;There are 28 different flavor substances in koumiss and distilled milk wine,mainly are 13 kinds of fatty acids and 13 kinds of esters.Through comparison,it is found that fermented milk wine is closer to koumiss than distilled milk wine.