Based On MS Combined With Stoichiometry Discriminant Analysis On Origin,Flavor Type And Quality Grade Of Liquor

Liquor,also known as "Shaojiu",is made from grain and cereals by cooking,saccharifying,fermenting,distilling,storing and blending.In addition,koji,yeast,etc.are used as its saccharification starter.It has a long history and enjoys high reputation at home and abroad.At present,the number of known flavor compounds in liquor exce eds1,000,accounting for about 1%-2% of the total liquor.The formation of these trace flavor compounds is jointly determined by a variety of factors,such as different brewing technology,different production materials,and different cellaring condition s,which will have an impact on liquor to a certain extent,and form different flavor types and grades,thus affecting the taste of liquor.In recent years,due to the lack of a unified ev aluation standard system in the liquor market,many illegal traders have taken advantage of this and replaced good liquor with low-end inferior liquor,thus disrupting the liquor market and endangering the legitimate rights and interests of consumers.In order to maintain the order of liquor market and safeguard the rights and interests of consumers,it is necessary to establish and explore a set of scientific,rapid and accurate methods for distinguishing liquor.Based on the above phenomena and problems,this study used GC-MS to comprehensively analyze the flavor compounds in liquor samples of different brands,different flavor types and different grades,and combined with the method of stoichiometry to explore and establish the evaluation method of finished liquor.The main research contents of this paper include:(1)This paper comprehensively explored the best test conditions for flavor compounds in liquor from the initial temperature,retention time,split ratio and other aspects of GC-MS,so as to ensure that the flavor compounds in liquor can be detected and analyzed to the greatest extent in the shortest time.The optimized detection conditions are as follows: the initial temperature is 40 ℃,maintained for 1min,then increased to 120 ℃ at a rate of 20℃/min,maintained for 1min,increased to 290 ℃ at a rate of 40 ℃/min,the split ratio is 50:1,and the MS interfa ce temperature is 280 ℃.EI ion source ionization energy 70 Ev;The temperature of ion source is 230 ℃;The scanning mass range is 39-550 m/z.(2)Flavor compounds in Luzhou-flavor liquors from six different regions were obtained by GC-MS,and the samples from six different regions cou ld be effectively grouped into six categories by cluster analysis.The first three principal components in the principal component analysis can effectiv ely express 92.85% of the information in the liquor samples,which can separate the six liquor samples from different origins.In the discriminant analysis,the accuracy of the determination results of six liquor samples from different producing areas was 100%.(3)GC-MS was used to determine the five liquor samples with different flavor types.Cluster analysis and principal component analysis were used to separate the five liquor samples with different flavor types.The first three principal components could effectively express 98.84% of the effective information in the liquor samples.The discriminant analysis can make the discriminant of 5 different flavor liquor samples100% correct.(4)GC-MS was used to analyze the flavor compounds of three different grades of liquor samples.Cluster analysis and principal component analysis could effectively separate the three grades of liquor samples,and the first three principal components in principal component analysis could effectively express 90.49% of the information in the liquor samples.The accuracy of discriminant analysis for three grades of liquor samples can reach 100%.It can effectively separate three different grades of liquor samples.