The Biochemistry of Vinegar Production

Chin Wai Ho, Shazrul Fazry, Azwan Mat Lazim, and Seng Joe Lim* Chapter Authors: Chin Wai Ho (https://orcid.org/0000-0002-8371-8311">https://orcid.org/0000-0002-8371-8311) Shazrul Fazry (https://orcid.org/0000-0002-7072-8609">https://orcid.org/0000-0002-7072-8609) Azwan Mat Lazim (https://orcid.org/0000-0002-6342-2695">https://orcid.org/0000-0002-6342-2695) Seng Joe Lim (https://orcid.org/0000-0002-9460-5136">https://orcid.org/0000-0002-9460-5136) Affiliations Seng Joe Lim and Chin Wai Ho Centre for Biotechnology and Functional Food, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, MALAYSIA Azwan Mat Lazim Centre for Advanced Materials and Renewable Resources, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, MALAYSIA Shazrul Fazry Tasik Chini Research Centre, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, MALAYSIA Email Addresses: Seng Joe Lim*: joe@ukm.edu.my Chin Wai Ho: chinwaiho@gmail.com Azwan Mat Lazim: azwanlazim@ukm.edu.my Shazrul Fazry: shazrul@ukm.edu.my *Author for correspondence Vinegars are made by a two-stage fermentation process: alcoholic fermentation of any type of fermentable sugar, followed by acetous fermentation (ethanol oxidation). The alcoholic fermentation is carried out by yeasts (e.g., Saccharomyces cerevisiae) that convert the fermentable sugars in the medium into alcohol under anaerobic conditions. Subsequently, the acetous fermentation occurs in the presence of oxygen to convert the alcohol into acetic acid. Practically, there are two main types of traditional acetification methods for vinegar production: the surface oxidation and the submerged acetification. The surface oxidation is a much slower process compared to the submerged fermentation, which is rapid due to the higher contact surface with oxygen (dissolved in the medium). The main biochemical pathways and enzymes of the vinegar fermentations (alcoholic and acetous), as well as the basic metabolic features of the species (yeasts and acetic acid bacteria) involved in vinegar production, are briefly highlighted in this chapter.