Flavor Diversity Research Of Different Round Maotai-flavor Liquor With Gas Chromatography And Electronic Nose/Tongue Bionic Sensory Technology

Maotai-flavor liquor is one of the traditional liquor in China.Its production process includes two times of adding food and seven times of distilling liquor at a year production cycle.Different round Maotai-flavor liquor is obtained respectively by seven times of distilling.Different round liquor has certain difference in the flavor characteristics,which were caused by the different chemical compositions and quantities.The “Maotai-flavor” commercial liquors can be obtained by blending different round liquors according to certain proportion.Therefore,flavor diversity research of different round Maotai-flavor liquor has great significance,which can not only help to guide the blending of commercial liquors,but also can be further combined with liquor brewing process to get round liquors with better quality.In this paper,gas chromatography technology and electronic nose/tongue technology were used to investigate the flavor diversity of different round Maotai-flavor liquor.The main research contents and conclusions are as follows:(1)The diversity of chemical composition and content in different round Maotai-flavor liquor was investigated by gas chromatography.The chromatographic separation conditions were chosen firstly.LZP-930 chromatographic column was used as separation column in the experiment,and the temperature programmed conditions were as follows: the initial temperature is 35 ?(holding time 4 min),up to 100 ? at 7 ? / min rate(hold time 2 min),and then up to 150 ? at 10 ? / min rate(holding time 10 min).Split ratio is 35:1;the hydrogen flow rate: 40 m L/min,the air flow rate: 400 m L/min,the make-up flow rate: 30 m L/min.the carrier gas flow rate: 0.9 m L/min;the injection port temperature: 210 ?;the detector temperature: 230 ?;sample injection volume: 1.0 ?L.Under the optimized experimental conditions,trace aroma components in seven round Maotai-flavor liquors were separated and analyzed.The content of acids,alcohols,esters and aldehydes substance in different round Maotai-flavor liquor were compared,and then the reasons which caused the variety characteristics of different round Maotai-flavor liquor were discussed preliminarily.Also,the total acid content,total ester content,total aldehyde content and alcohol degree in different round Maotai-flavor liquor were detected,their change trend in different round Maotai-flavor liquor were compared and analyzed.(2)Electronic nose technology was used to examining aroma differences among different round Maotai-flavor liquor.The sample quantity,heating temperature,air volume were optimized.the optimum conditions for the sample quantity is 1000 ?l,heating temperature is 25 ?,headspace volume is 100?l Under the optimized experimental conditions,electronic nose technology was used to detecting different round Maotai-flavor liquor samples and obtained the sensors response data.the response signal recognition effect were compared when used principal component analysis and discriminant factor analysis,on the whole,principal component analysis to distinguish the recognition effect is better than discriminant factorial analysis.(3)The electronic tongue technique was adopted to investigate taste differences in different round Maotai-flavor liquor.Firstly,electrode cleaning fluid were choosen,it was found that when using 43% ethanol aqueous solution as the cleaning fluid the experiment had the best detection effect.And under the optimal experimental condition,the multivariate statistical analysis was used to analyse the sensors reflection data,the experiment results showed that the principal component analysis method could effectively distinguish the different distilling liquor,the discriminant factor function analysis could accurately identify their category.(4)The correlations between the electronic tongue sensor response signal and total acid content,total aldehyde content and alcohol content n liquor were investigated by partial least squares method,and then predict these physical and chemical index with established equation.It was found that the predict effect were different,all round Maotai-flavor liquors have the best prediction effect towards alcohol degree,and the prediction effect of total ester was also good,prediction effect of total acid and total aldehyde content in different round Maotai-flavor liquor is feasible.