An immobilized
lipase suitable for fat interesterification has been prepared by precipitation with
acetone of a commercial
lipase from Rhizopus arrhizus onto
diatomaceous earth. As observed previously with a less active
enzyme from Aspergillus sp., the interesterification activity was enhanced by addition of purified
lipase or by high loadings of commercial
enzyme. The interesterification activities reached maximum values in both cases. For immobilized preparations with purified
enzyme, interesterification activity was also enhanced by the presence of a precoat of
glutaraldehyde cross-linked commercial
lipase. A 2.9-L column of immobilized
lipase was used to interesterify batches of
shea oleine (67 kg) and shea oil (40 kg). Little activity was lost processing
shea oleine, but slow
poisoning of the bed occurred when shea oil was fed to the column.