Processing Optimization And Product Flavor Analysis Of Jiangxi Rice Wine

Jiangxi rice wine is a kind of traditional Chinese rice wine made by adding jiuqu to glutinous rice.It is rich in nutrients and beneficial to human health.However,the traditional Jiangxi rice wine has some problems,such as uncertain technology process and unstable product quality.This study improved the brewing process of traditional Jiangxi rice wine and investigated the changes of nutrients,bacterial community,antioxidant capacity and aroma substances in the fermentation process of Jiangxi rice wine,which has great significance for guiding the production and quality improvement of Jiangxi rice wine.The main research results and conclusions are as follows:(1)A new type of Jiangxi rice wine was prepared using mixed glutinous rice and rice as raw materials.The effects of different fermentation processes on the physicochemical indexes and sensory evaluation of the new Jiangxi rice wine were investigated by single factorial and orthogonal experiments.The results showed that the optimal fermentation process of Jiangxi rice wine was as follows: 10% rice,0.3%jiuqu,5 days pre-fermentation,2 days post-fermentation.The fermented rice wine was moderately sweet and sour,with a total acidity of 4.7 g/L,a total sugar of 67.1g/L,an alcohol content of 12.4%vol,and a sensory score of 87.43.(2)During the fermentation process of Jiangxi rice wine,the total acidi and alcohol content of Jiangxi rice wine showed an increasing trend.The content of total sugar and soluble solids first increased and then decreased,the maximum of total sugar was 136.5 g/L,and the maximum of soluble solids was 29.1%.The content of free amino acids in rice wine reached the maximum value of 720.9 mg/kg on the fifth day of fermentation,and was 535.1 mg/kg after fermentation,showing a trend of first increasing and then decreasing.Starch content in wine lees decreased from 78.3% to10.0%.On the other hand,the protein content increased from 8.3% to 27.2%.Fat content first increases and then fluctuates within a certain range(1.8%～2.1%).(3)High-throughput sequencing technology was used to analyze the bacterial community succession during the fermentation of Jiangxi rice wine.Based on the taxonomic analysis of the bacterial community at the phylum level,the core phylum in the fermentation process of rice wine was Proteobacteria and Firmicutes.Further analysis at the genus level showed that Acinetobacter was the most dominant bacterium with the highest abundance during rice wine fermentation.Acinetobacter had a trend of first increasing and then decreasing during fermentation.Bacillus and Enhydrobacter showed an overall decreasing trend in the fermentation process;Pseudomonas,Pantoea and Enterobacter showed an overall increasing trend in the fermentation process.(4)The functionality of Jiangxi rice wine was enhanced during the fermentation process.The DPPH radical scavenging capacity of the rice wine at the end of fermentation was comparable to that of Trolox at 8.36 mg/m L.The total antioxidant capacity was comparable to that of Trolox at 0.38 mg/m L.The antihydroxyl radical capacity was comparable to that of Trolox at 3.73 mg/m L.Moreover,the anti-superoxide anion radical capacity was 89.97 U/L.The content of free amino acids detected during the fermentation of rice wine and their TAV values indicated that the total content of UAA and SAA in rice wine was greatly increased.Glutamic acid,alanine,valine,arginine,and histidine contributed most to the flavor of Jiangxi rice wine.The contribution of SAA and UAA to the flavor of Jiangxi rice wine reached the level of significant effect at the end of fermentation.The analysis of volatile flavor compounds showed that 62 volatile flavor substances were detected during the fermentation of rice wine.Two volatile flavor substances with the highest relative contents were alcohols and esters;among them,phenethyl alcohol,ethyl caprylate,ethyl caprylate,ethyl laurate,ethyl myristate,ethyl palmitate,ethyl oleate,and ethyl linoleate were relatively high throughout the fermentation process.A total of 31 volatile compounds were detected in the finished rice wine.The volatile flavor compounds that significantly contributed to the flavor of rice wine were ethyl isobutyrate,isobutyl acetate,3-hydroxy-2-butanone,propionaldehyde,ethyl butyrate,3-methylbutyraldehyde,ethyl caproate,isoamyl acetate,and ethyl caprylate.(5)Using glutinous rice and rice as raw materials,a rice wine plant with an annual capacity of 1,200 tons was designed based on the research results in Chapter 2.The design mainly includes site selection,product scheme,production process,material accounting,equipment selection,and comprehensive economic estimation.The results of economic calculation and analysis show that the annual sales of the rice wine factory is 24 million RMB and the annual net profit is 4.26 million RMB.