Study On Processing Technology And Qualityl Of Hongqu Persimmon Wine

Persimmon is rich in nutrition and has high edible value and pharmacological effect.Using persimmon to ferment persimmon wine not only has high nutritional and health value,but also can make full use of Persimmon Resources in China.However,due to the problems of single organic acid,tannin and pectin content in persimmon,the taste and flavor of persimmon wine are not good.In this paper,Hongqu was introduced into persimmon wine fermentation system.In order to obtain Hongqu persimmon wine with good taste,harmonious flavor and stable quality,the following four parts were studied:(1)The optimal fermentation conditions were obtained by single factor and response surface optimization experiments with alcohol,reducing sugar,total acid and sensory score.The optimal fermentation conditions were as follows: the addition of Hongqu was 3.00%,the initial sugar content was 21%,and the yeast addition was 275 mg / kg.Under these conditions,the sensory score of Hongqu persimmon wine was 84.657.The volatile components of Hongqu persimmon wine and common persimmon wine were detected by HS-SPME-GC-MS.The results showed that 45 kinds of volatile compounds were detected in Hongqu persimmon wine,including 27 esters,4 alcohols,7 acids and 7 other substances.23 kinds of volatile components were detected in common persimmon wine,including 8 esters,3 alcohols,5 acids and 7 other substances.Compared with the two kinds of wine,the flavor structure of persimmon wine was changed after adding Monascus.(2)Illumina Mi Seq high-throughput sequencing was used to analyze the bacterial and fungal community structure of Hongqu persimmon wine samples at six fermentation stages.The dominant bacteria in the fermentation of Hongqu persimmon wine were Lactobacillus,Pseudomonas,Pantoea,Acinetobacter,Sphingopyxis,Burkholderi,Streptophyta,Halomonas and Sediminibacterium The dominant fungi are Monascus,Issatchenkia and Saccharomyces spp.During the fermentation process,the bacterial and fungal community structure of Hongqu persimmon wine had succession.According to the analysis of volatile components in different brewing stages of Hongqu persimmon wine,the content of alcohols increased gradually;the content of acids increased first and then decreased;the types of esters increased and accumulated gradually with the fermentation time.The analysis of organic acids showed that the total content of organic acids in Hongqu persimmon wine increased gradually and reached the peak value on the third day,and then decreased gradually.The proportion of organic acids varies with the fermentation time.At the beginning of the fermentation,citric acid,acetic acid and succinic acid are dominant.With the fermentation of malolactic acid(MLF),lactic acid and acetic acid gradually become the main organic acids.Finally,O2 PLS method was used to establish the correlation between microorganisms and volatile components and organic acids.The results showed that there were strong interactions between 11 species of microflora and 26 species of volatile compounds,among which Saccharomyces cerevisiae,Spironolactone,halophile and Pseudomonas showed significant positive correlation with the same volatile components of 19 species.Most fungi and bacteria are related to organic acids,especially to the formation of tartaric acid,oxalic acid,lactic acid and acetic acid.(3)The combination of compound clarifier and membrane filtration was used to clarify Hongqu persimmon wine.The results showed that the best clarification process was as follows: a(compound clarifier ratio)1:2,B(treatment temperature)46℃,C(treatment time)14.9 h.under these conditions,the transmittance of Hongqu persimmon wine was 91.9%,which was only 0.29% different from the theoretical prediction value.The results showed that the 0.8μm microfiltration membrane could retain the characteristics of glass persimmon wine,to a large extent,avoid losing color,the membrane flux was higher,and the clarification glass method was more suitable than other membrane pore size persimmon wine.(4)The effects of sunlight,ultraviolet light,temperature and color protecting agent on the pigment stability of Hongqu persimmon wine were studied.The results showed that sunlight,ultraviolet light and high temperature could affect the stability of pigment in Monascus persimmon wine.The results showed that the color retention rate of red yeast persimmon wine was 80.399%,75.294%,70.95%,68.29%,67.72% and 64.97% under UV light,but the color protection effect was not obvious after heating at 70℃ for 22.62 h(half-life).The results showed that sodium citrate ascorbic acid had the best color protection effect.