Study On Fermentation Of Pear Fruit Wine And Distillation And Aging Technology Of Brandy

In this paper,Korla fragrant pear was used as material to prepare fragrant pear fruit wine by using three kinds of Saccharomyces cerevisiae and two fermentation methods.The optimum temperature of crude brandy was optimized,and the original brandy was distilled.Oak chips were added to the original brandy,and the dissolution promotion process of the original brandy was optimized by ultrasound.By measuring the basic physical and chemical indexes of brandy during different aging treatments,quantitatively describing the change rule of analysis,and combining fuzzy mathematics and aroma components,the best ultrasonic dissolution promotion process and aging promotion method were comprehensively analyzed and determined.The specific results are as follows:(1)In this paper,the basic physical and chemical indexes of fermented mash of EC118,KI and KD yeast in the whole fruit pulp and juice fermentation process were studied,and the aroma components of fragrant pear fruit and six kinds of treated fruit wine were analyzed.The overall change trend of each index of the three yeasts in the whole fruit pulp and juice fermentation process did not show the difference between treatments,but there were certain differences in the change level of each index.The total phenol content of whole fruit pulp fermented wine was higher than that of fruit juice fermented wine.Among the three yeasts,KI and KD yeast have better aroma-producing ability.The fruit wine obtained has appropriate acidity,high alcohol content and clear color.The total phenol content and aroma types of whole fruit fermentation are higher than those of fruit juice fermentation.KI yeast has the most aroma components,and the total phenol content of fruit wine fermented by KI whole fruit pulp is the highest.Therefore,KI whole fruit pulp is the best strain and fermentation method for pear wine.(2)By comparing the distribution of methanol and fusel oil in the distillation process of crude brandy at different temperatures,it is concluded that the higher the distillation temperature,the higher the content of methanol fusel oil,the higher the content of methanol in the head and tail,and the higher the content of fusel oil in the head.A total of 64 aroma compounds were detected in 4 kinds of wine samples,among which 33,38,30 and 38 were detected at 50?,70?,90?and 100?,respectively,with the highest content of esters.70?and 100?(control)were determined as the distillation temperature of crude brandy,and the secondary distillation was carried out,and the distillation temperature was both 100?.The data of QDA spider web map of two treatments showed that the original brandy finally obtained by distilling crude brandy at 70?was mainly fragrant and sweet;The original brandy obtained by distilling crude brandy at100?is mainly burnt.(3)According to the single factor and response surface optimization test,the optimal conditions for ultrasonic dissolution of tannin in original brandy were as follows:ultrasonic time 11 min,ultrasonic power180 W,oak addition 1.20 g/100 m L,soaking days 20 d.Under these conditions,tannin content was 1319.42mg/L.The regression model fitted well to the test,which indicated that the results obtained by response surface design were accurate and reliable.This model can not only be used to analyze and predict the dissolution effect of tannins in the aging process of original brandy,but also be used to accelerate the aging of original brandy and improve the quality of brandy.(4)By comparing physical and chemical indexes and QDA statistical analysis of fragrant pear brandy during five aging treatments,and combining with methanol and fuzzy mathematics after aging,it was concluded that chroma,total acid and total ester increased in different degrees,while p H and alcohol content decreased in different degrees.QDA statistical results show that the aroma of irradiation treatment is floral and fruity,and the sensory performance of aroma is the best.Combined with fuzzy mathematics,the comprehensive scores of irradiation and ultraviolet treatment are 87.53 and 87.26,respectively.The aroma of irradiation treatment is the best,and the taste of ultraviolet treatment is better.The aging sui Tab.for aging fragrant pear brandy can be obtained by blending irradiation and ultraviolet at a ratio of 7:3.(5)The results showed that 66 kinds of aroma components were detected in 6 kinds of brandy samples,and 29,34,34,39,42 and 47 kinds of aroma components were detected in control,microwave,ultraviolet,ozone,irradiation and blending,which were higher than those in control group.The types of ester substances OAV>1 are the most.PCA extracts four principal components,and the cumulative variance contribution rate reaches 96.32%.The comprehensive evaluation function is F=0.468F₁+0.289F₂+0.126F₃+0.117F₄.The scores of aging brandy samples are blending,irradiation,ultraviolet,microwave,ozone and control.Comprehensive consideration,aroma type,aroma content and principal component analysis showed that the blended fragrant pear brandy had the best quality.