皂土、硫酸处理对苹果汁发酵过程中果胶甲酯酶活性以及苹果蒸馏酒甲醇含量的影响

Effect of bentonite and sulfuric acid treatment on pectin methylesterase (PME) activity during applejuice fermentation and methanol content of apple distilled liquor

新鲜苹果汁分别采用皂土、硫酸处理后,经酿酒酵母(Saccharomyces cerevisiae)发酵获得苹果基酒,经二次蒸馏制备苹果蒸馏酒。研究苹果汁发酵过程中果胶甲酯酶(PME)活性及甲醇含量的变化,探究皂土、硫酸处理对苹果蒸馏酒中甲醇含量、风味物质及感官品质的影响。结果表明,皂土和硫酸处理苹果汁PME活性在发酵4 d后分别降低90.48%、91.75%,均未检出甲醇。与对照相比,皂土和硫酸处理的苹果基酒PME活性分别降低33.18%与24.71%,甲醇含量分别降低37.76%与30.88%;皂土和硫酸处理的苹果蒸馏酒甲醇含量分别降低47.46 mg/L、34.86 mg/L;酯类物质总含量分别提高145.73 mg/L、38.51 mg/L;醇类物质总含量分别提高144.04 mg/L、降低530.79 mg/L;总挥发酸含量分别降低50.18 mg/L、61.90 mg/L。皂土处理蒸馏酒感官评分最佳(91.3分)。综上,2种处理均可有效降低苹果蒸馏酒甲醇含量,皂土处理可以显著提高苹果蒸馏酒的品质。

After fresh apple juice was treated with bentonite and sulfuric acid,respectively,the apple base wine was fermented by Saccharomyces cerevisiae,and the apple distilled liquor was prepared by double-distillation.The pectin methylesterase(PME)activity and the changes of methanol content during apple juice fermentation were studied,and the effects of bentonite and sulfuric acid treatments on methanol contents,volatile substances and sensory quality of apple distilled liquor were investigated.The results showed that PME activity of apple juice treated with bentonite and sulfuric acid decreased 90.48%and 91.75%respectively,after fermentation for 4 d and methanol was not detected.Compared with the control,the PME activity of apple base liquor treated with bentonite and sulfuric acid decreased 33.18%and 24.71%,respectively,and the methanol content decreased 37.76%and 30.88%,respectively.The methanol content of apple distilled liquor treated with bentonite and sulfuric acid decreased 47.46 mg/L and 34.86 mg/L,respectively.The contents of total esters increased 145.73 mg/L and 38.51 mg/L,respectively.The contents of total alcohols increased 144.04 mg/L and decreased 530.79 mg/L,respectively.Total contents of volatile acids decreased 50.18 mg/L and 61.90 mg/L,respectively.The sensory scores of distilled liquors treated with bentonite was the best(91.3).In summary,the 2 treatments could effectively reduce the methanol content of apple distilled liquor,the bentonite treatment could significantly improve quality of the apple distilled liquor.