Optimization Of The Fermentation Conditions Of Red Raspberry Wine And Changes Of Volatile Compounds During Brewage

This thesis mainly focused on the study of fermented red raspberry wine. The process technology and related parameters had been determined. The first step of which was processing of red raspberry using enzyme treatment, with the optimum adding capacity controlled at 0.016%, enzyme digestion time 4.5 hours, temperature 39℃. The second step of which was alcohol fermentation, with the fruit wine yeast rate controlled at 4%, fermentation temperature 24℃, initial sugar concentration 18°Bx and pH3.4. Clarification experiments of fermented red-raspberry wine by simple clarifier and multiple clarifiers including gelatine, chitosan and bentonite respectively were carried out, and their effects were evaluated through the determination of the absorbency value and the light transmittance. It was showed that the light transmittance at 800nm could be the guide line of red-raspberry fermented wine. The two clarifiers of bentonite and chitosan could clarify the fermented wine preferably in simple clarifier; The combination of bentonite and chitosan had better effects than that of the single one. Volatile components of red raspberry wine were extracted by solvent extraction method. Then they were analyzed by GC-MS, Changes of Volatile Compounds of red raspberry wine during Brewage were studied. The results showed as below:1,There were 54 compounds of fermented red raspberry after the end of the main fermentation(10d) which were identified through the retrieval in NIST bank, accounting for 89.40% of the total area of chromatogram eluting peaks. The main flavoring compounds were: 2,3-Butanediol, 20.49%; 3-Methyl-1-butanol, 12.83%; Aceticacid, 5.84%; PHenylethyl Alcohol,5.46%; Ethyl hydrogen succinate, 4.47%; 1,3-Butanediol, 4.36%; Ethyl acetate, 3.34%; 2-Methyl-1-butanol, 3.15%; 3-Hydroxy-2-butanone, 2.89%; Benzoicacid, ethyl ester, 2.69%; 2-Pyrrolidinecarboxylic acid-5-oxo-, ethyl ester, 2.03%; 4-Hydroxy-benzeneethanol, 1.98%; Propanoic acid, 2-hydroxy-, ethyl ester, 1.64%; 1,3-Propanediol, diacetate, 1.26%.2,There were 81compounds of fermented red raspberry after the end of the back fermentation(20d) which were identified through the retrieval in NIST bank, accounting for 78.50% of the total area of chromatogram eluting peaks. The main flavoring compounds were: 2,3-Butanediol, 19.44%; PHenylethyl Alcohol, 6.33%; 3-Methyl-1-butanol, 14.1%; 2-Pyrrolidinecarboxylic acid-5-oxo-, ethyl ester, 4.27%; Butyrolactone, 4.12%; Propanoic acid, 2-hydroxy, ethyl ester, 2.22%; 2-Methyl-1-butanol, 2.13%; Benzeneethanol, 4-hydroxy-, 1.15%; 1-Butano-l, 3-methyl-, acetate, 1.00%. 3,There were 65 compounds of fermented red raspberry afer the end of brewing (4months)which were identified through the retrieval in NIST bank, accounting for 87.59% of the total area of chromatogram eluting peaks. The main flavoring compounds were 2,3-Butanediol, 36.77%; 2-Pyrrolidinecarboxylic acid-5-oxo, ethyl ester, 9.87%; Ethyl hydrogen succinate, 6.81%;1-Butanol, 3-methyl-, 6.6%; PHenylethyl Alcohol, 6.27%; Butyrolactone, 3.84%; Propanoic acid, 2-hydroxy-, ethyl ester, 1.97%; Benzyl Alcohol, 1.3%; 2-Furancarboxylic acid, 1.35%; 1,3-Dioxolane,2,2,4,5-teramethyl-,trans,1.14%; Butanedioic acid, diethyl ester, 1.13%; 1-Butanol, 2-methyl-, 1.07%; Benzene ethanol, 4-hydroxy-, 0.96%.