【作者】 胡廷；

【导师】 刘树文；

【作者基本信息】 西北农林科技大学 ， 葡萄与葡萄酒学， 2008， 硕士

【摘要】 苹果酸-乳酸发酵(malolactic fermentation,MLF)是葡萄酒酿造中非常重要的二次发酵过程,对酿造优质红葡萄酒来说尤其重要[李华,2001]。在葡萄酒制造发达国家,大都根据乳酸菌的营养需求研制一些促进发酵的营养剂产品,这些营养剂含有氨基酸,维生素,和细菌繁殖所必需的物质,可以缩短乳酸菌在葡萄酒中的潜伏期,从而促使苹果酸-乳酸发酵更快、更顺利地进行。有关这方面的研究,国内还未见报道,也没有类似产品的研发。MLF能否顺利启动并最终完成受菌种及其所处的环境条件(葡萄酒的乙醇含量,pH值,SO2浓度及营养条件等)的影响。酒精发酵完成后酒中营养物质的缺乏会抑制乳酸菌的MLF,生产上常常出现MLF发酵迟滞甚至接种失败。因此,有必要根据菌种的营养需求,研制一种发酵助剂以便顺利地完成MLF。本试验选用西北农林科技大学葡萄酒学院优选酒酒球菌SD-2a,对其进行苹果酸-乳酸发酵过程中所需的营养物质及其最佳比例,番茄汁的冷冻干燥工艺,发酵助剂的配比以及应用进行了研究,旨在为今后的发酵助剂产品的研制提供一定的依据。以求解决生产中常常出现的MLF发酵迟滞、缓慢、甚至接种失败等问题,从而更好地为生产实践服务。研究结果表明:1.通过正交试验,确定了酒酒球菌SD-2a所需的营养物质及其最佳配比为番茄汁30%、异亮氨酸、甲硫氨酸、缬氨酸、亮氨酸、天门冬氨酸各0.03g/L,精氨酸、脯氨酸、色氨酸、盐酸半胱氨酸、各0.01g/L,硫酸镁0.2g/L、硫酸锰0.05g/L。2.采用真空冷冻干燥技术,探讨了搁板温度、物料厚度等因素对番茄汁冻干时间、品质的影响。结果表明,搁板温度每提高10℃,冻干时间缩短2～3h;厚度每增加2.0mm,冻干时间延长2h;研究确定番茄汁真空冻干的最佳工艺参数为采用预冻温度-35℃、搁板温度50℃、装料厚度5.0mm。3.用酒酒球菌SD-2a干粉进行苹果酸乳酸发酵时,加发酵助剂和不加发酵助剂,苹果酸降解率有显著差异。不加发酵助剂,苹果酸降解率为42.81%;加入含番茄汁的发酵助剂和含番茄汁干粉的发酵助剂,苹果酸降解率分别为72.04%和69.83%,苹果酸含量有了较大幅度的减少,苹果酸降解率显著提高。更多还原

【Abstract】 Malolactic fermentation (MLF) is a indispensable processing technology for modern wine making, especially for red wine of high quality.In developed wine making countries, most of the wineries use commercial fermentation promoters which are based on nutrition requirements of LAB to inoculate MLF.These fermentation promoters include amino acids, vitamins and other nutrients for LAB to reproduce, so can make the MLF faster and successful. But research on this is scarcely at home. Startup of MLF depend on the species of LAB and the conditions of the wine(.content of ethanol, SO2 pH,etc.).In practice, MLF is often sluggish and appears fall of inoculation.It is indispensable to prepare a Fermentation Promoter based on nutrition requirements of LAB,so it can make the MLF faster and more successful.This paper studied on the best proportion of the nutrition requirements of choice Oenococcus oeni SD-2a.in the process of fermentation,vacuum freeze-drying craft of tomato juice, the composition and application of Fermentation Promoter. The purpose is to provide an experimental basis for preparation of Fermentation Promoter. The results indicated:1.The best proportion of the nutrition requirements of Oenococcus oeni SD-2a is 30% tomato juice,isoleucine、methionine、valine、leucine、aspartic acid which are 0.03g/L apiece,tryptophan、Hcl-cysteine、arginine and proline which are 0.01g/L apiece ,0.2g/LMgSO4、0.05g/LMnSO4.2.Discussing the influence of shelf temperature, material thickness and other factors on freeze-drying time and quality of tomato juice: freeze-drying time is shortened 2 to 3 hours while shelf temperature raises 10℃; thickness raises 2.0mm while freeze-drying time delays 2 hours. Freeze-drying craft parameters of tomato juice: advance freezing temperature is -35℃、shelf temperature is 50℃、material thickness is 5.0mm. 3.When MLF conducted by using Oenococcus oeni SD-2a powder,adding fermentation promoter or not have marked difference. Malic acid division rate is 42.81% when adding no fermentation promoter , Malic acid division rate are 72.04% and 69.83% when adding fermentation promoter including tomato juice and tomato juice powder.So adding fermentation promoter can decrease the content of malic acid remarkably.更多还原