Esterification and Interesterification Reactions of Lipases from Rice Bran and Papain in Oleic Acid-Glycerol/n-Butanol and two Vegetable Oil Blends

The ability of crude rice bran lipase and
commercial papain lipase was evaluated for
esterification of oleic acid with glycerol and n-butanol
and interesterification of palm oil and rice bran oil
blend. For esterification of oleic acid with glycerol / nbutanol,
the reaction proceeded upto 1.9%, 3.0%
(37UC), 2.5%, 8.6% (50UC) at atmospheric pressure
and 1.5%, 8.3% (37UC) 7.3%, 6.4% (50UC) under
reduced pressure for rice bran and papain lipases
respectively. During the interesterification reaction,
concentration of LLL decreased by 24.5, 38.5 and
6.3%; PPP decreased by 73.9, 68.1 and 14%; LLP /
LPL decreased by 11.6, 28.2 and 15.2% with an
increase in the concentration of LOL (134.4, 78.7 and
120.3%), POO (9.1, 10.5 and 2.7%) and PPO (4.9,
10.1, 2.3%) for the three studied enzymes viz.,
lipozyme IM-60 (as a control), rice bran and papain
lipases respectively. The physical state of the blend
after treatment with lipozyme IM-60, crude rice bran
and papain lipases has changed from semisolid to
completely liquid state even at 5-10°C while the
physical blend was a semisolid at RT / 25°C / 5-10°C.
It is concluded from the study that these enzymes can
be used for carrying out esterification and
interesterification reactions which is being reported for
the first time.