reactors or continuous systems for the modification of oils and fats by lipase-cata-
lyzed interesterification.
11.8 Processes for the modification of oils and fats via
enzymatic interesterification
Most studies for the modification of oils and fats by lipase-catalyzed interesterifica-
tion have used STR or simple glass vessels for the reactions. PBR were shown to be
more promising for industrial developments with immobilized lipases. Fuji Oil used
a STR for the large-scale production of CBE by lipase-catalyzed interesterification
(Hashimoto, 1993; Owusu-Ansah, 1994). The schematic arrangement of the process
is shown in Figure 10. As may be seen from the scheme, STR was used for the
reaction system and hexane was used as the medium. Ethyl stearate served as
the acyl donor to reduce the melting point and boiling point. Ethyl stearate also
has higher solubility in hexane than stearic acid. Therefore, the viscosity of the sys-
tem will be lower and the distillation temperature can be reduced for purification.
Unilever have developed a two-stage process for the production of CBE and Be-
tapol (Figure 11) (Quinlan and Moore, 1993; Rozendaal and Macrae, 1997). The
substrate passed the first packed enzyme bed and the first stage product was purified
by distillation to remove the free fatty acids. The purified product was further mixed
210 11 Modification of Oils and Fats by Lipase-Catalyzed Interesterification
Figure 10. Process scheme for the production of cocoa butter equivalents (CBE) via lipase-catalyzed
interesterification in a stirred-tank reactor. (Adapted from Owusu-Ansah, 1994.)