The Australian Wine Research Institute, Glen Osmond, PO Box 197, Adelaide, SA, 5064, Australia.
World J Microbiol Biotechnol. 2012 Jan;28(1):255-65. doi: 10.1007/s11274-011-0814-3. Epub 2011 Jun 23.
Malolactic fermentation (MLF) is an integral step in red winemaking, which in addition to deacidifying wine can also influence the composition of volatile fermentation-derived compounds with concomitant affects on wine sensory properties. Long-established winemaking protocols for MLF induction generally involve inoculation of bacteria starter cultures post alcoholic fermentation, however, more recently there has been a trend to introduce bacteria earlier in the fermentation process. For the first time, this study shows the impact of bacterial inoculation on wine quality parameters that define red wine, including wine colour and phenolics, and volatile fermentation-derived compounds. This study investigates the effects of inoculating Shiraz grape must with malolactic bacteria at various stages of alcoholic fermentation [beginning of alcoholic fermentation (co-inoculation, with yeast), mid-alcoholic fermentation, at pressing and post alcoholic fermentation] on the kinetics of MLF and wine chemical composition. Co-inoculation greatly reduced the overall fermentation time by up to 6 weeks, the rate of alcoholic fermentation was not affected by the presence of bacteria and the fermentation-derived wine volatiles profile was distinct from wines produced where bacteria were inoculated late or post alcoholic fermentation. An overall slight decrease in wine colour density observed following MLF was not influenced by the MLF inoculation regime. However, there were differences in anthocyanin and pigmented polymer composition, with co-inoculation exhibiting the most distinct profile. Differences in yeast and bacteria metabolism at various stages in fermentation are proposed as the drivers for differences in volatile chemical composition. This study demonstrates, with an in-depth analysis, that co-inoculation of yeast and bacteria in wine fermentation results in shorter total vinification time and produces sound wines, thus providing the opportunity to stabilise wines more rapidly than traditional inoculation regimes permit and thereby reducing potential for microbial spoilage.
苹果酸-乳酸发酵（MLF）是红葡萄酒酿造过程中的一个重要步骤，除了降低葡萄酒的酸度外，还可以影响挥发性发酵衍生化合物的组成，从而影响葡萄酒的感官特性。传统的 MLF 诱导酿造方法通常涉及在酒精发酵后接种细菌发酵剂，但最近有趋势是在发酵过程的早期引入细菌。本研究首次展示了细菌接种对葡萄酒质量参数的影响，这些参数定义了红葡萄酒，包括葡萄酒颜色和酚类物质以及挥发性发酵衍生化合物。本研究调查了在酒精发酵的不同阶段（酒精发酵开始时（与酵母共接种）、酒精发酵中期、压榨时和酒精发酵后）向设拉子葡萄汁中接种乳酸菌对 MLF 动力学和葡萄酒化学成分的影响。共接种大大缩短了整个发酵时间，最多可达 6 周，细菌的存在并不影响酒精发酵的速度，并且发酵衍生的葡萄酒挥发性特征与在酒精发酵后期或发酵后接种细菌的葡萄酒明显不同。MLF 后观察到的葡萄酒颜色密度总体略有下降，但不受 MLF 接种方案的影响。然而，花色苷和着色聚合物组成存在差异，共接种表现出最明显的特征。发酵过程中不同阶段酵母和细菌代谢的差异被认为是挥发性化学成分差异的驱动因素。本研究通过深入分析表明，在葡萄酒发酵中同时接种酵母和细菌可以缩短总酿造时间并生产出优质的葡萄酒，从而提供了比传统接种方案更快稳定葡萄酒的机会，从而减少了微生物污染的潜在风险。
