3.1. Dehairing experiments and material balance
Preliminary trials were taken up to standardize the optimal
conditions such as pH, enzyme concentration and
duration for complete dehairing of skins and hides using
the bacterial protease preparation by dip method (data
not shown). The optimal conditions for the production of
dehaired pelts from goatskins and cowhides by dip method
for 6 h were 1% enzyme, 0.2% sodium carbonate and 100%
float at pH 7.5–9.0 and 2% enzyme, 0.4% sodium carbonate
and 100% float at pH 7.5–9.0, respectively. Visual observation
studies on the experimental dehaired pelts from goatskins
and cowhides apparently revealed complete absence
of fine hairs and epidermis and the experimental pelts were
whiter than the controls due to elimination of sulfide in the
process. It was reported earlier that the removal of residual
fine hairs remained the greatest obstacle to the development
of hair saving enzymatic process (Paul et al., 2001).
Process details were presented for processing 1000 kg of
salted skins and hides (Table 1). Paste method was adopted
for conventional and enzyme-assisted dehairing of goat
skins. However, dip method was employed for experimen-
tal dehairing since the enzyme did not have action upon
hair components. In addition, the bath did not contain sul-