Optimization Of Fermentation Technology And Aroma Component Analysis Of Grape Skin Residue Distilled Spirit

In this study,the white grape skin residue from the Xinjiang wine company was used as raw material,and the strain suitable for grape skin residue fermentation was screened by strain mutagenesis.According to the single factor and response surface test,the optimal fermentation process of three varieties of grape skin residue distilled liquor was determined,and distilling it.The aroma components of three varieties of grape skin residue distilled spirit were analyzed.Finally,based on the previous research,the safety indicators and sensory analysis were carried out.The specific research results are as follows:(1)The starting strain was mutagenized by UV and ARTP mutagenesis.The optimal condition for UV mutagenesis was that the starting yeast strain was irradiated for 30 s from a 30 W UV lamp for 140 s,and the lethality rate was 93.94%;the optimal conditions for ARTP mutagenesis was a gas flow rate of 10 SLM,a power supply of 120 W,a temperature of 20?,and a lethality rate of 98.75%at 100 s.After compared the strains screened by the two mutagenesis methods,the target strain was determined to be Y6-8.The alcohol production and acid production capacity of the strain were increased by 28.13%and 214.93%respectively compared with the original strain.(2)The effects of fermentation temperature,fermentation time,inoculum size,solid-liquid ratio and diammonium phosphate addition on the fermentation of three grape skin residue distilled spirit were studied by single factor experiment,and the optimal fermentation technology for grape skin residue distilled spirit was determined by response surface optimization.The optimum fermentation conditions of Italian Riesling grape skin residue distilled spirit were determined as follows:fermentation temperature 26.6?,fermentation time 3 d,inoculation volume 7%,ammonium hydrogen phosphate 0.4 g/kg,solid-liquid ratio 1:0.7.The alcoholicity of fermentation liquid was 3.20%vol,total acid content was 10.19 g/L.The optimum fermentation conditions of Chardonnay grape skin residue distilled spirit were as follows:fermentation temperature 27?,fermentation time 3 d,inoculation volume 7%,the addition of ammonium hydrogen phosphate 0.4 g/kg,solid-liquid ratio 1:0.65.The alcoholicity of fermentation liquid was 2.90%vol,and the total acid content was 9.76 g/L.The optimum fermentation conditions for fermentation of Riesling grape skin residue distilled spirit were as follows:fermentation temperature 26.7?,fermentation time 4 d,inoculation amount 9%,addition amount of ammonium hydrogen phosphate 0.4 g/kg,solid-liquid ratio 1:0.7.The alcoholicity of fermentation liquor was 4.15%vol,total acid content was 9.63 g/L.After the end of the fermentation,it was distilled through a self-made distillation apparatus to obtain three different varieties of grape skin residue distilled spirits.(3)The volatile aroma components of three different varieties of grape skin residue distilled spirits were tested by HS-SPME-GC-MS technology and analyzed.A total of 114 volatile aroma compounds were detected in three grape skin residue distilled spirits,among which the volatile compounds of esters,alcohols and terpenes were high.By comparing and analyzing the main aroma compounds,it was found that the aroma components of Italian Riesling grape skin residue distilled spirit were more abundant.In order to further study the relationship between aroma compounds and grape skin residue varieties,22 aroma components and 8 types of aroma compounds were analyzed by principal component analysis,and a quality evaluation model based on principal component analysis was established.Through the calculation of the model,the comprehensive score was Italian Riesling grape skin residue distilled spirit>Riesling grape skin residue distilled spirit>Chardonnay grape skin residue distilled spirit.(4)Sensory and safety analysis of the obtained 3 grape skin residue distilled spirits.The physical and chemical indicators of the three pomace distillations were tested by the national standard method.The physical and chemical indexes of three varieties of grape skin residue distilled spirit were tested by the national standard method.All the indexes of three wine samples met the requirements of GB 2757-2016 National Standard for Food Safety Distilled Liquor and Prepared Liquor.The sensory evaluation of three varieties of grape skin residue distilled spirit was carried out by the sensory evaluation method of fuzzy mathematics.The comprehensive score was as follows:Italian Riesling grape skin residue distilled spirit>Chardonnay grape skin residue distilled spirit>Riesling grape skin residue distilled spirit.