苹果酒苹果酸乳酸发酵乳酸菌的筛选

首先根据乳酸菌对苹果酒风味的贡献情况筛选出 3株乳酸菌 ,再从微生物角度对乳酸菌的生理特征以及环境因素对乳酸菌生长的影响进行了研究和比较 ,发现OenococcusoeniL4能够在SO2 和乙醇体积分数分别为 5 0mg/L和 6% ,pH 3 .2时良好的生长 ;该菌具有良好的苹果酸降解能力 ,达到 2 2 8 5 2mg/(L·d) ,表明O oeniL4能够适应于我国起泡苹果酒的酿造 ,是 1株优良的苹果酒苹果酸乳酸发酵菌株。     

苹果酒酿造中的苹果酸-乳酸发酵

在苹果酒酿造中进行苹果酸-乳酸发酵,乳酸菌通过分解苹果酸,产生乳酸,引起其他有机酸的变化,使苹果酒的口感、质量得以改善。pH、温度、SO_2、酒度通过影响乳酸菌的活动而影响苹果酸-乳酸发酵的进行。保证苹果酒苹果酸-乳酸发酵进行的条件为:温度16～18℃,总SO_2含量<70mg/L,pH<3.70,酒精体积分数低于13％。     

肠膜明串珠菌在苹果酒苹果酸乳酸发酵中的应用探讨

通过在苹果酒中添加肠膜明串珠菌启动苹果酸乳酸发酵,研究了温度、pH和酒精度等因子对苹果酸-乳酸发酵的影响表明,肠膜明串珠菌能够启动苹果酸-乳酸发酵,其中温度、pH和酒精度均对苹果酒的柔和指数和感官评价有显著影响,不同发酵条件下酿造的苹果酒柔和指数在1.33～7.94之间,感官评分在73.7～91.3之间.添加肠膜明串珠菌后,苹果酸的浓度变化在322.45mg/L～692.44mg/L之间,pH值提高了约0.06～0.11,苹果酒的口感变得柔和,风味得到明显改善.     

添加肠膜明串珠菌后的苹果酒苹果酸乳酸发酵工艺优化研究

以苹果酒风味的柔和指数为指标,对添加肠膜明串珠菌后的苹果酒苹果酸乳酸发酵(MLF)工艺条件进行优化。结果表明,发酵温度、pH和肠膜明串珠菌接种量等因素会影响MLF后的苹果酒柔和指数;采用二次正交回归旋转实验确定了苹果酒MLF的适宜工艺参数为:发酵温度21.78℃,pH 3.53,肠膜明串珠菌接种量4.65%(v/v),按该工艺生产柔和指数从2.73提高到3.54,苹果酒的风味得到了明显改善。     

龙眼葡萄苹果酸—乳酸发酵降酸新技术,新工艺

长城公司葡萄酒产品的原料来自怀来、涿鹿两县，由于葡萄高产，造成龙眼葡萄的酸度较高。为解决降酸问题，我公司于 １９９７年酿酒期引进了优良乳酸菌种，探索苹果酸－乳酸降酸发酵的新途径，并于当年及１９９８年进行了多次不同方法的试验。 有关苹果酸－乳酸发酵（ＭＬＦ）降酸在法国早已应用，而且也有资料记载，参考有关资料数据，进行了苹果酸－乳酸发酵试验。１试验目的１．１利用苹果酸－乳酸发酵来降低葡萄酒的酸度，提高酒的风味、质量，提高葡萄酒的生物稳定性。１．２可以减少因酒石酸钾降酸给葡萄酒中带来的钾离子、酒石酸根离…     

葡萄酒苹果酸乳酸发酵研究进展

苹果酸乳酸发酵(Malolactic fermentation,MLF)指在乳酸菌作用下将L-苹果酸脱羧基形成L-乳酸的过程,是葡萄酒生产难以控制的二次发酵过程,主要由酒类酒球菌引起.MLF对大部分红葡萄酒、一些白葡萄酒和汽酒最终的质量有重要的影响.自发进行的MLF结果往往难以预测,甚至引起葡萄酒的腐败.主要阐述引起MLF的微生物、MLF对葡萄酒品质的影响、MLF的生物学、影响MLF的因素、MLF在葡萄酒酿造中的应用等方面的研究现状,以期探索更好的控制MLF的技术.     

苹果酸乳酸发酵的研究进展

苹果酸乳酸发酵是现代葡萄酒、苹果酒酿造工艺中非常重要的二次发酵过程。葡萄酒、苹果酒经过苹果酸乳酸发酵以后 ,原有的酸涩和粗糙感降低 ,而变得柔和、圆润且具有果香味。文中根据国内外研究成果 ,分析总结了苹果酸乳酸发酵的机理并且对苹果酒酿造过程中乳酸菌的一些生长特性进行了阐述。在此基础上 ,论述了现代生物技术在苹果酒和葡萄酒生产中的新应用。     

枇杷酒中苹果酸乳酸发酵优良乳酸菌的分离与鉴定

目的:分离获得高耐受二氧化硫的枇杷酒苹果酸乳酸发酵(MLF)菌,为果酒生物降酸提供优良乳酸菌资源.方法:采用平板划线法,从自然发酵的枇杷酒中分离乳酸菌,并通过耐受性试验筛选优良的MLF乳酸菌;通过形态学特征、生态学特征、生理生化特征和16S rDNA序列同源性分析法对目标菌进行鉴定.结果及结论:R23和R35分别被鉴定为植物乳杆菌(Lactobacillus plantarum R23)和干酪乳杆菌(Lactobacillus casei R35);R23与R35均具有MLF能力,且可耐受120mg/L的总SO2浓度,是2株优良的枇杷酒MLF菌.     

不同苹果酸--乳酸发酵菌种特性的研究

本实验研究了ML34、31DH和自然乳酸(CK)在宁夏地区的发酵特性,结果表明:三种菌种pH在3.1的条件下不能启动MLF;ML34、31DH在pH3.2、3.3的条件下能顺利启动、完成MLF,pH越高发酵进程越快,CK只有在pH3.3的条件下才能完成MLF,其中31DH对低pH的适应能力最强.ML34、31DH在较低温度条件下均可顺利启动、完成MLF,并随温度的升高发酵进程加快;CK只有在22℃条件下才能完成发酵.三种乳酸菌种对SO2的浓度比较敏感,当SO2的浓度达到14.2mg/L时,ML34、31DH菌种的发酵进程大大减缓;CK不能完成发酵.31DH在本地区表现最好.     

苹果酸—乳酸发酵控制

武威（古凉州）是葡萄最佳生态区之一,得天独厚的生态环境,加之莫高人十几年所选择的国际名贵葡萄品种,所生产的葡萄酚类物质含量高,糖酸比适中。先进的设备,精湛的工艺,所酿制的葡萄酒香气优雅,口感醇厚圆润,回味悠长,风格独特。为加快红葡萄酒成熟,缩短生产周期,提高感官质量和稳定性[1,2],做出更高档次红葡萄酒,我公司派技术人员对全国几大葡萄酒公司进行调查,发现对红葡萄酒进行二次发酵的厂家寥寥无几,究其原因,原料含酸量一般低于7.0g／L（酒石酸计）进行生物降酸意义不大。我公司为解决限制红葡萄酒品质的关键问题…     

葡萄酒苹果酸-乳酸发酵代谢机理

苹果酸 -乳酸发酵 (MLF)是葡萄酒中乳酸菌 (LAB)进行的细菌降酸过程。伴随着MLF,还生成了双乙酰 ,乙偶姻等物质 ,从而影响着 MLF后酒的风味。通过对 MLF生化机理的研究 ,提出了 MLF是 LAB利用胞内苹果酸 -乳酸酶 (MLE)直接催化苹果酸转变成乳酸的过程。本文还对双乙酰及其衍生物的产生机理、MLF能量代谢和 MLE基因工程等方面进行了评述。     

Malolactic Activity of Lactic Acid Bacteria during Sauerkraut Fermentation

ABSTRACT: The frequency of lactic acid bacteria (LAB) involved in sauerkraut fermentation with (MDC⁺) or without (MDC^-) the ability to decarboxylate malic acid was determined. The MDC⁺ phenotype was found in > 99% of homofermentative LAB isolated from commercial fermentations. In contrast, heterofermentative LAB isolates from 0.25, 3, 7, and 10 d had only 53%, 54%, 15%, and 11% MDC⁺ phenotype, respectively, indicating that more than 1 strain or species was involved. The malolactic reaction was demonstrated in cabbage juice with known strains of Leuconostoc mesenteroides , raising the question of desirability of such activity in cultures selected for the controlled fermentation of cabbage.     

Malolactic Fermentation and Secondary Metabolite Production by Oenoccocus oeni Strains in Low pH Wines

Abstract: Different wine varieties, including some with low pH, were studied to determine the ability to grow and produce secondary metabolites of a previously selected autochthonous Oenococcus oeni strain (C22L9), compared with a commercial strain. Monitoring of malolactic fermentation (MLF) was carried out by microbiological and chemical analysis of wines. The concentration of some major volatile compounds and biogenic amines in wines before and after malolactic fermentation was also determined. The results showed major differences in MLF duration both between wines and strains, although the differences between strains were slight for most of the analyzed compounds. Statistically significant differences in citric acid degradation were found in all wine varieties and it was confirmed that O. oeni C22L9 is a poor degrader of citric acid; this means that MLF can be prolonged without the risk of producing high concentrations of diacetyl and acetoin. Sensory analysis of wines after MLF showed similar characteristics in wines from both strains. This study thus shows that O. oeni C22L9 possesses even better sensory and fermentation properties than the commercial strain and can be used in wines with different characteristics, which makes it highly valuable for industrial use. Practical Application: The increasingly use of grape varieties of low pH in winemaking and the higher alcohol content of wines, as a consequence of the climatic change, make interesting the study of the behavior during MLF of O. oeni strains in order to determine their ability to grow, when growth conditions are not optimal, and to produce secondary metabolites. A comparative study was conducted using an autochthonous O. oeni strain (C22L9) and a commercial O. oeni strain and 4 wine varieties.     

Malolactic Fermentation as a Technique for the Deacidification of Hard Apple Cider

ABSTRACT:  Malolactic fermentation (MLF), the conversion of malate to lactate, is an important process leading to the deacidification of hard apple cider. MLF is dependent on the levels of inhibitory factors such as sulfur dioxide and ethanol. To assess the effect of these 2 factors on MLF, hard apple cider was produced from pasteurized, unfiltered apple cider ( Malus domestica  cvs Red Delicious, Golden Delicious, Braeburn, and Fuji). Apple cider was treated with 2 levels of sulfur dioxide (50 and 80 ppm) and then fermented using  Saccharomyces cerevisiae  montrachet. After the primary fermentation, 1 set of the samples remained unadjusted and 100% ethyl alcohol was used to adjust other sets of samples to 7%, 9%, or 11% (v/v) ethanol. Following the ethanol adjustment,  Oenococcus oeni  MCW was used to initiate the MLF in half of the samples. Cider parameters monitored throughout the fermentations included organic acid content, titratable acidity, pH, ethanol production, and sugar content. Since samples containing either sulfur dioxide level had similar sugar utilization rates and ethanol production it was concluded that sulfur dioxide had no effect on the primary fermentation. Sulfur dioxide content was shown to have an impact on MLF. There was no difference in the rate of malic acid consumption, but lactic acid production was faster in the 50-ppm sulfur dioxide samples. MLF was not inhibited by ethanol content.     

苹果酸-乳酸发酵在葡萄酒酿造中的应用

苹果酸一乳酸发酵(MLF)是红葡萄酒酿造的必经步骤，是葡萄酒生物降酸的主要方法，MLF可有效降低葡萄酒中的苹果酸。苹果酸是一种具有强烈辛酸味的双羧基酸，常规的物理、化学降酸方法对苹果酸不起作用，而MLF可降解苹果酸，使之转化为单羧基的、口感酸味柔和的乳酸，使葡萄酒的有机酸含量降低，酒体协调性增加，并可提高其生物稳定性和风味复杂性。本文介绍了MLF的机理、引起MLF的微生物及其在葡萄酒酿造中的作用，对影响MLF环境因素和现代发酵工程技术(固定化技术和膜生物反应器)在MLF中的新的应用与发展也作了阐述。     

生物工程技术在苹果酸-乳酸发酵中的应用

苹果酸－乳酸酵母是葡萄酒中的苹果酸在乳酸菌的作用下转变为乳酸和CO2的过程，它有利于葡萄酒质量的提高。介绍了生物反应器和采用基因工程方法构建的苹果酸－乳酸酵母进行葡萄酒生物降酸的技术。（1）游离生物反应器。使用细胞循环式发酵以在到高细胞生物量；或控制连续发酵；（2）固定化细胞，有包埋法和吸附法。（3）固定化酶技术。（4）苹果酸－乳酸酵母的应用。构建的苹果酸－乳酸酵母能在7d内将苹果酸转为乳酸，并具有良好的酿酒特性。（津京）     

Microbial Populations and Malolactic Fermentation of Apple Cider using Traditional and Modified Methods

The evolution of yeasts and lactic acid bacteria was examined during two methods of cider making: the traditional employed unwashed apples of different varieties and the modified used a sole washed acidic apple variety with temperature control during the cider making process. The alcoholic fermentation was carried out mainly by Kloeckera apiculata and Sacharomyces cerevisiae species, and their distributions were similar in the two methods. In the traditional, the malolactic fermentation proceeded at the same time as alcoholic fermentation and the “piqure lactique” occurred. In the modified method, no malolactic fermentation took place. In all musts, a fundamentally heterofermentative lactic flora was found, with Lactobacillus species most abundant in the traditional process.