Lipozyme IM-catalyzed interesterification for the production of margarine fats in a 1 kg scale stirred tank reactor

Lipozyme IM-catalyzed interesterification of the oil blend between palm ste arin and coconut oil (75/25 w/w) was studied for the production of margarin e fats in a 1 kg scale batch stirred tank reactor. Parameters such as lipas e load, water content, temperature, and reaction time were investigated. Th e reusability of Lipozyme IM was also studied under optimized conditions. T he interesterification products were monitored by analysis of triacylglycer ol profiles, the contents of diacylglycerols, free fatty acids (FFA), and s olid fat contents. The contents of some triacylglycerol species, which were categorized by equivalent carbon number (ECN), namely ECN34, 36, 48, and 5 0, decreased by 6.0, 5.9, 5.8, and 13.7%, respectively, after enzymatic int eresterification, similar to the reduction of those species after chemical interesterification, 6.6, 6.0, 7.1, and 12.9%, respectively. On the other h and, those of ECN38, 40, 42, 44, and 46 increased University of Denmark, by 1:1, 1.6, 6.8, 16.7, and 6.5%, respectively, in comparison with the increa se of those Lyngby, Denmark species after chemical interesterification, 0.2 , 1.5, 6.5, 17.0, and 9.2%, respectively. Lipase load and reaction time had great influence on the degree of interesterification. Edible Oils Division , A Lipozyme IM load of 6% was required for a reaction of 6 h and at 60 deg rees C, to reach a stable degree of interesterification. Temperature variat ion in the range of 50-75 degrees C did not affect the reaction degree as w ell as the contents of diacylglycerols, but the content of FFA slightly inc reased with higher temperature. Addition of water to the enzyme increased t he contents of diacylglycerols and FFA in the products linearly. However, i t had no effect on the degree of interesterification for the first batch wh en the enzyme was reused. Lipozyme IM was stable in the 10-batch test after adjusting the water content in the system. The relationship between the co ntent of water in the system and that of FFAs in the products was evaluated and discussed.