The reaction mechanism was formulated as a threestep
reaction [2,17,18]. The first step involves the
reaction between the triglyceride and one molecule of
alcohol, leading to diglycerides and one molecule of
ester. The second step is the reaction of the diglycerides
with a second molecule of alcohol, leading to monoglycerides
and another molecule of ester, and the third
one the reaction of monoglycerides with the third molecule
of alcohol leading to glycerin and ester. The
kinetics of this mechanism is very complicated. Even if
we consider the reaction between a triglyceride having
the same fatty residue (R1) and alcohol, the overall
process involves at least twelve equilibrium reactions
(Scheme 1):