Enzyme treatment and viscosity of d

Enzyme treatment and viscosity of date fruit pulp
The apparent viscosity of this mixture was measured
at hourly intervals up to 5 h and then after 24 h, using a
Brookfield viscosimeter, and the results are presented in
Table 6. As can be seen from this data, the apparent
viscosity of date fruit pulp increased at 1 h and then
consistently decreased with the passage of time at all
enzyme concentrations used in this study. The Birhi
variety gave slightly higher apparent viscosity than the
Safri variety; probably, the former had a higher pectin
content (Table 1). There was almost 100% reduction in
the viscosity values among all the pulp samples treated
with pectinase/cellulase enzyme preparations. The
reduction in the viscosity of other fruit juices due to
enzymatic hydrolysis of pectin has been reported by a
number of workers (Gupta & Girish, 1988; Urlaub,
1996). The initial slight increase in viscosity of date fruit
pulp may possibly be due to the increased extraction of
pectic substances through the action of these enzymes
on the cell wall materials of date fruits.