Non-saccharomyces yeast and acetic acid bacteria in balsamic-styled vinegar production : a biochemical process analysis

Abstract

Grape producers and wine makers in South Africa are currently affected by various challenges, which include anti-alcohol lobbies, climate change, over-production in some vintages and the lack of transformation including empowerment in certain sectors of the industry. Climate change and global warming lead to poor quality wine grapes and as a result, poor quality wine. Therefore, there is a need to channel grapes away from normal wine production and provide an alternative source of income for the industry. The overall aim of this study was therefore to provide an alternative outlet for overproduced wine grapes by producing balsamic-styled vinegar (BSV) in South Africa. Balsamic vinegar is different from other vinegars because it is a direct product of grape must and not a downstream or by-product of wine production. Balsamic vinegar entails lower production costs when compared to the production of wine due to the low technological process requirements during production; therefore, this could be an opportunity for small business entrepreneurs with low capital start-up. In addition, balsamic vinegar can command a high price, which is a benefit for grape producers. The primary aim of this investigation was to biochemically analyse a BSV production process in which 5 non-Saccharomyces yeast and 15 acetic acid bacteria (AAB) were used for a multicultural alcoholic-acetous (EtOH-AcOH) fermentation process. To achieve this aim, a fermentation process was designed where the data generated was fitted into kinetic models and the proliferation including the population dynamics of the microbial consortia were studied.