Timing of malolactic fermentation inoculation in Shiraz grape must and wine: influence on chemical composition |
| |
Authors: | Caroline E Abrahamse Eveline J Bartowsky |
| |
Institution: | (1) The Australian Wine Research Institute, Glen Osmond, PO Box 197, Adelaide, SA, 5064, Australia; |
| |
Abstract: | 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. |
| |
Keywords: | |
本文献已被 PubMed SpringerLink 等数据库收录! |
|