Optimize The Production Pcocess And Analysis Of Aroma Components Of Ice-pingguoli Pears Fermented Wine

Pingguoli pears as the Rosaceae pear belong to the fruit of Pyrus fruit tree.,it's one of the high-quality varieties in Pyrus bretschneideri Rehd,a natural hybrid between variant in Shali pear system and Qiuzili pear.The surface of fruit has some punctiform flush,and it's shaped like apple,the average single fruit weighing about 250.0g.With a small core,the edible portion accounts for about 85.9% of the fruit,and the flesh is creamy and delicate,the texture is crisp and juicy,it taste sweet and sour.Pingguoli pears contain a variety of vitamins,minerals,amino acids,trace elements,fructose and other substances required by the human body.It has the effects of lowering blood pressure,eliminating phlegm,relieving cough,enhancing appetite and preventing cancer.Pingguoli pears is mainly distributed in Yanbian,Jilin Province,and used as fresh food.At present,the processed products include Pingguoli peasr wine,Pingguoli pears beverage,Pingguoli pears vinegar,Pingguoli pears crisp,etc.In this experiment,Yanbian Pingguoli pears was used as raw material.At first,the best production technology was determined.Then the optimal fermentation process parameters and the best clarification method of iced Pingguoli pears fermented wine were determined by single factor test and response surface optimization test.The developed iced Pingguoli pears fermented wine has a light reddish-brown color,the liquor is clear and non-suspended matter.It tastes mellow,slightly acidic and refreshing.It has the unique fresh aroma of iced Pingguoli pears.In addition,GC-MS technique was used to detect the aroma components of Pingguoli pear fermented wine and iced Pingguoli pears fermented wine in different periods.After systematic analysis and comparison,the specific conclusions are as follows:1.Though the single-factor test,best fermentation time was determined as 22 d,the optimum fermentation process parameters of iced Pingguoli pears fermented wine were determined by response surface optimization test and validation test.The results are as follows: fermentation temperature 20?,yeast addition 0.5g/L,pH 3.8,under these conditions,the alcohol content of iced Pingguoli pears fermented wine was 12.4%vol.The order of influence factors on the fermentation process of iced Pingguoli pears fermented wine was yeast addition>fermentation temperature>pH value.2.The best clarification method of iced Pingguoli pears fermented wineThe single factor test of iced Pingguoli pears fermented wine was carried out respectively by natural clarification,bentonite clarification and chitosan clarification,and the chitosan has the best clarification effect.Finally,it was confirmed that chitosan is the clarification agent for the iced Pingguoli pears fermented wine,the addition is 0.075g/L and the light transmittance is 97.5%.3.We selected Pingguoli fermented wine aged for 1 year,iced Pingguoli pears fermented wine aged for 6 months and 1 year,and the aroma components were detected by solvent extraction and GC-MS.The results show as follows: 31 volatile aroma components were detected in 1 year old Pingguoli fermented wine,the main aroma component was monoethyl succinate,and 27.42% of the total aroma component.There were 39 volatile aroma components detected in 6 months old iced Pingguoli fermented wine,the main aroma component was isopentanol,and 42.24% of the total aroma component.And 35 volatile aroma components were detected in 1 year old iced Pingguoli fermented wine,the main aroma component was 2,3-butanediol,and 33.2% of the total aroma component.Among them,the aroma substances are quire different,and the only common aroma components contained is isoamyl alcohol.