Lipase catalyzed interesterification of Amazonian patauá oil and palm stearin for preparation of specific-structured oils.

Abstract

This study showed that enzymatic interesterification of Amazonian oils could be an important tool in order to produce new oils with physicochemical properties that improve the applications of these raw materials. Structured oils of Amazonian patauá oil and palm stearin using two lipases were produced in three different enzymatic systems: first, a crude lipase from the fungus Rhizopus sp (a microorganism isolated in our laboratory); second, a commercial lipase; and third, to check any synergistic effect, a mixture of both lipases (Rhizopus sp and commercial). The lipase from Rhizopus sp was specific in the incorporation of oleic acid at the sn-1,3 positions of the triacylglycerol, resulting in an oil richer in saturated fatty acid in the sn-2 position. This enzyme, produced by solid-state fermentation, even though crude, was fatty acid and positional specific and able to operate at low concentration (2.5%, w/w). In the second enzyme system, the commercial lipase from Thermomyces lanuginosus was not specific in the tested conditions; there was no change in the distribution of saturated and unsaturated fatty acids in the three positions of the triacylglycerol profile, there was only a replacement by the type of fatty acid at the same position. In the third enzyme system, the mixture of both lipases shows no synergic effect. The structured oils retained the concentration of bioactive α- and γ- tocopherol in the three enzyme systems. Triacylglycerol classes and Thermal behavior tests indicated the formation of more homogeneous triacylglycerols, especially the mono and di-unsaturated.