Study On Fermentation Technology Of Compound Fruit And Vegetable Wine

Compound fruit and vegetable wine is made from the fruits and vegetables of daily consumption,It is not only contains a variety of nutrients beneficial to the human body,but also overcomes the shortcomings of single fruit wine with poor flavor and insufficient nutrients.Combining the unique flavor,brilliant color and fresh aroma,the fruit and vegetable wine has better sensory flavor,and nutrition and health protection functions.The main research contents of this experiment are as follows:(1)Using apple juice,kiwi juice,tomato juice and carrot juice as raw materials,sensory evaluation and alcohol strength as responses,the material compostition was optimized by Mixture design and then the sensory quality of material compostition was evaluated by fuzzy mathematics comprehensive evaluation.(2)Single fermentation,compound fermentation and different proportions of fermentation for four strains of yeast were carried out to screen out the optimum yeast for compound fruit and vegetable wine.(3)The temperature,fermentation time,pH and inoculation amount were optimized with alcohol strength and polyphenol content as the response values.(4)Plackett-Burman design was used to screen out the five single factors,and then the transmittance was taken as the response value to optimize the clarification process conditions,and finally the composition of the best process was compared.(5)The electronic nose(E-nose)and headspace solid-phase microextraction-gas chromatography-mass spectrometry(SPME-GC-MS)were used to analyze and compare the volatile constituents before and after fermentation.The results show:(1)The optimal ratio of the four raw materials was 10%kiwi juice,10%carrot juice,10%tomato juice and 70%apple juice,the alcohol content of compound fruit and vegetable wine under this condition was 4.95%vol,and the sensory evaluation score was 85.0.The products obtained had excellent color,aroma,and taste,and had the unique style of fruit and vegetable wine.Fuzzy comprehensive evaluation showed that the product was acceptable to consumers.(2)The suitable strain for the fermentation of compound fruit and vegetable wine was2.137-active dry yeast,with a ratio of 1:2.Under obove mentioned comdition,the fermentation speed was fast,and the alcohol strength was as high as 8.50%vol,the total acid value was low,the color was stable and orange-yellow,clear and transparent,and the sensory evaluation score was 87.7 for the fermented product.(3)The optimum fermentation conditions for the main fermentation were:pH of 3.8,yeast inoculation quantity of about 10×10~6/mL,temperature of 27?,and a suitable fermentation time of 4 d.Under these conditions,the alcohol strength of the compoundfruit and vegetable wine was 7.20%.Vol,polyphenol content was 62.55 mg/g.(4)The optimum clarification conditions for compound fruit and vegetable wine were:gelatin solution of 0.90g/L,pectinase of 0.1g/L,bentonite solution of 1.13g/L,and the light transmittance obtained under this condition was 97.1%.(5)A total of 39 major compounds were identified before and after fermentation,including11 esters,11 alkanes,9 alcohols and 8 others.The types and composition of volatile components vary greatly,indicating that the main aroma changes of the composite fruit and vegetable wine from juice to wine were completed before and after fermentation.These results are consistent with the results of electronic nose PCA.Therefore,it can be seen from the results of SPME-GC-MS and electronic nose analysis that the electronic nose can well distinguish the flavors before and after fermentation.