固定化リパーゼを用いたエステル交換反応による高度不飽和トリアシルグリセリンの調製
1993 年 42 巻 1 号 p. 30-35
詳細
1993 年 42 巻 1 号 p. 30-35
Fish oils such as sardine oil, icosapentaenoic acid concentrated oil (EPA-25) and docosahexaenoic acid concentrated oil (DHA-20) were transesterified with polyunsaturated fatty acids (PUFA) prepared from the original oils by low temperature crystallization, in a enzymatic reaction system using immobilized lipase (Lipozyme) originating from Mucor miehei.
The optimum reaction conditions were : 6 times PUFA for EPA-25 by molar ratio, 30 % Lipozyme for EPA-25 by weight, 5% water for Lipozyme by weight, 2 h incubation time at 60°C, under which conditions the transesterification ratio reached approximately 32 %. The recovery of triacylglycerol was about 95 %, indicating competitive hydrolysis to be suppressed effectively under the conditions used and PUFA content of the triacylglycerol increased to 62 %.
Possibly as a result of the substrate specificity of Lipozyme, the transesterification ratio reached approximately 44% in the soybean oil-myristic acid system, this being 12% higher than that of the fish oil-PUFA system, EPA was more easily incorporated into triacylglycerol than DHA. The preparation of triacylglycerol with high DHA content was thus carried out by additional transesterification in the fish oil-PUFA system and the DHA content of the resulting triacylglycerol was 3.6 times that of the original fish oil.
Lipozyme could be recycled more than 20 times under the present transesterification conditions.
