| Summary: | Immobilization of lipase enzyme on silica gel with encapsulation method
has been performed. This study aims to improve reuse of lipase immobilized by
silica gel, as well as the enzyme stability to the effects of temperature changes and
pH in the hydrolysis reaction of palm oil. The immobilized lipase enzyme made
by mixing a solution of lipase in phosphate buffer solution of silica sol gel at
room temperature to form a solid gel which then allowed to stand for 24 hours.
Percentage of silica encapsulated enzyme were analyzed by the biuret method
using spectrophotometer UV-Vis. The catalytic activity and the ability to use
repeatedly in the hydrolysis reaction of the immobilized lipase enzyme on silica
gel has been tested, as well as its stability against temperature changes and pH of
the hydrolysis reaction.
The results showed that the percentage of lipase immobilized on silica gel
is 64.024%, but after 5 washes, percentage of immobilized lipase only 28.041%.
Activity of lipase immobilized silica gel is lower than the free lipase. However,
the lipase enzyme immobilized by silica gel can be used up to 5 times in
hydrolysis reaction with the highest reaction percentage of free fatty acid product
is 17.407% and the lowest is 8.601%. Lipase immobilized silica gel is more stable
against temperature changes and pH than free lipase enzymes, each enzyme has an
optimum temperature at 35 °C and optimum pH 7.
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