Bhat et al.
and then acetous”. The raw materials used for vinegar production include
rice, grapes, malt, apple, honey, potatoes, whey or any other sugary food
(Bamforth 2005). In human history, vinegar appears at the beginning
of agriculture with the discovery of alcoholic fermentation from fruits,
cereals and vegetables. The genesis of vinegar can hardly be distinguished
from the origin of wine. Although vinegar has always been considered
among the lowest quality products of fermented foods, it has also been
used as a food condiment, as a preservative agent and, in some countries
as a healthy drink (Solieri and Giudici, 2009).
Vinegar production
Vinegar is the product made from the conversion of ethyl alcohol to acetic
acid by a genus of bacteria, Acetobacter . Therefore, vinegar can be produced
from any alcoholic material from alcohol-water mixtures to various fruit
wines (Peppler and Beaman 1967). Vinegar bacteria, also called acetic acid
bacteria (AAB), are members of the genus Acetobacter and characterised by
their ability to convert ethyl alcohol (C 2 H 5 OH) into acetic acid(CH 3 COOH)
by oxidation as shown below:
Vinegar is a solution of acetic acid produced by a two-step bioprocess.
action of yeast. In the second step, AAB oxidize the ethanol into acetic acid
in an aerobic process. AAB are well known for their ability to spoil wines
because they can produce large amounts of acetic acid from ethanol and
other compounds present in wines (Joyeux et al., 1984).
Substrates used in vinegar production
One of the critical steps in vinegar production is the preparation of the
raw material (Solieri and Giudici 2009). This step is required to obtain