2.5. Analytical methods
At 24 h intervals, fermented broths (in triplicate) were removed
and the contents were analyzed for total sugar and ethanol. The
ethanol content of the fermented broth was determined by measuring
the specific gravity of the distillate according to the procedure
described by Amerine and Ough [14]. In this procedure, the
weight of a certain volume of an alcohol distillate was compared
to the weight of exactly the same volume of distilled water. The ratio
of the weights of the two (alcohol:water) gave the specific gravity
of the distillate [14]. The total sugar was assayed by the
Anthrone method [15]. The pH was measured using a pH meter
(Systronics, Ahmadabad, India) fitted with a glass electrode. Fermentation
kinetics were calculated using the formulae by Bailey
and Ollis [16].