Study On The Optimization Of Preparation Process Of Tea-type Daqu And Its Effect On The Composition Of Tea-flavor Baijiu Base Liquor

There are rich resources in the summer-autumn tea,but limited by the quality of tea and it can not be used effectively,which caused low economic benefits and resources were wasted.Tea and Baijiu,as traditional Chinese beverages bring enjoyment to consumers’taste buds through unique flavors,with a variety of functional ingredients beneficial to human health.In this study,we combine summer-autumn tea and a traditional solid-state fermentation process to make Tea-type Daqu by using summer-autumn tea as one of the raw materials.Determine the optimum process parameter for the making of Tea-type Daqu by single factor experiment and orthogonal test,determination the physicochemical components,fermentation characteristics microorganisms,and aroma components of Tea-type Daqu and compared with ordinary Daqu.Choose Tea-type Daqu as saccharifying fermenting agent and adding summer-autumn tea as one of the raw materials to brew Tea-flavor Baijiu,determine the volatile component,non-volatile components of Tea-flavor Baijiu and compared with ordinary Strong-flavor Baijiu.This study provides the theoretical basis for the value-added utilization of summer-autumn tea resources and the development of Tea-flavor Baijiu,there are the results of the study are as follows:1.When the addition amount of summer-autumn tea was 15%,the crushing degree of summer-autumn tea was 20 mesh,the moisture content was 35%,and the incubation days were 25 d,The saccharifying power of Tea-type Daqu was 369.72 mg/g*h,and the fermenting power was 0.158 g/g*72h,Tea-type Daqu had the best quantity ratio relationship between fermenting power and saccharifying power,and the quality of Daqu was the highest.2.In terms of physical and chemical components of Daqu:The starch contents of 5%,10%and 15%Tea-type Daqu were 53.49%,49.87%and 48.75%,respectively,which were significantly lower than that of ordinary Daqu.The p H values of 5%,10%and 15%Tea-type Daqu were 6.07,5.93 and 5.82,respectively,which were significantly lower than those of ordinary Daqu.The amino acid nitrogen of 10%and 15%Tea-type Daqu were223.07 mg/100g and 226.33 mg/100g,respectively,which were significantly higher than that of ordinary Daqu.The acidity of 5%,10%and 15%Tea-type Daqu was 0.94,0.9 and1.09 mmol/10g,respectively,which was significantly higher than that of ordinary Daqu.In terms of fermentation characteristics,the fermentation power of 5%and 10%Tea-type Daqu was 0.163 and 0.195 g/g*72h,respectively,which was significantly higher than that of ordinary Daqu.The saccharifying power of 5%,10%and 15%Tea-type Daqu was254.68,235.42 and 321.67 mg/g*h,respectively,which was significantly higher than that of ordinary Daqu.The liquefying power of 5%,10%and 15%Tea-type Daqu was 0.33,0.27 and 0.37 g/g*h,respectively,which was significantly lower than that of ordinary Daqu.The acid protease activity of 10%and 15%Tea-type Daqu was 64.77 U/g and 74.8U/g,respectively,which was significantly higher than that of ordinary Daqu.The esterification power of 5%and 10%Tea-type Daqu were 2323.16 and 2433.67 mg/50g*7d,respectively,which were significantly higher than that of ordinary Daqu.The number of bacteria in 5%,10%and 15%Tea-type Daqu was 2,1.6 and 1.7×10~6 CFU/g,respectively,which was less than that of ordinary Daqu.The number of molds in 5%,10%and 15%Tea-type Daqu was 1.2,1.6 and 1.9×10~5 CFU/g,respectively,which was more than that in ordinary Daqu.The number of yeast in 5%and 10%Tea-type Daqu was 6.6 and 8.3×10~4CFU/g,respectively,which was more than that in ordinary Daqu.In terms of aroma components:5%,10%and 15%Tea-type Daqu detected 69,69 and 70 aroma components,respectively,more than 55 kinds of ordinary Daqu,and four unique aroma components ofα-guruene,α-ionone,β-ionone and dihydroactinidiolide were detected in the three Tea-type Daqu.3.By detection and analysis of the Baijiu samples brewed from the laboratory,we find Tea-type Daqu mainly affects the content of various components in the Baijiu and the Summer-autumn tea brings more aroma substances during the fermentation process that increases the aroma content of the Baijiu.4.Headspace solid phase microextraction gas chromatography-mass spectrometry technology is used to analyze the base liquor which from pilot brewing test,and we find ethyl heptanoate(10.69%),ethyl laurate(3.02%),ethyl decanoate(7.53%)and ethyl benzoate(2.71%)in Tea-type Baijiu were different aroma substances compared with Strong-flavor Baijiu;Liquid-liquid extraction gas chromatography-mass spectrometry technology is used to analyze the base liquor,and we find ethyl palmitate(3.01%),diethyl succinate(0.6%)and ethyl myristate(0.09%)in Tea-type Baijiu were different aroma substances compared with Strong-flavor Baijiu;Detection and analysis of volatile and non-volatile components of Baijiu samples by high-resolution mass spectrometry combined with gas chromatography and liquid chromatography,we find the content of ethyl heptanoate in Tea-flavor Baijiu is much higher than that of Strong-flavor Baijiu and some special aroma substances such as linalool and nerolidol in Tea-flavor Baijiu;The number of non-volatile components is also higher than that of Strong-flavor Baijiu,and there are a large number of functional components that benefit for health;Can effectively distinguish between Tea-flavor Baijiu and Strong-flavor Baijiu by electronic nose.