| In order to prepare a MLM (Medium-long-medium, MLM) type medium-and long-chain triacylglycerols (MLCT) rich in lauric acid, the MLCT rich in 1,3-lauric-2-palmitoylglycerol (LaPLa) were synthesized by lauric acid hydrolyzing palm stearin. Using LaPLa content as an index, the performance of AO IM(lipase) was compared with the commercial enzymes RM IM and TL IM. At the same time, the reaction temperature, enzyme loading, substrate molar ratio and reaction time were optimized. The physicochemical properties of the MLCT were determined. The results showed that AO IM had good catalytic performance, and under the conditions of reaction temperature 65 ℃, substrate molar ratio (molar ratio of palm stearin to lauric acid)1∶ 10, enzyme loading 10% and reaction time 2.5 h, the LaPLa content reached 40.59%. The physicochemical properties analysis showed that compared with palm stearin, the acid value (0.19 mgKOH/g) and iodine value (37.35 gI/100 g) of purified MLCT decreased and its peroxide value(4.85 mmol/kg) increased. Both the initial crystallization temperature (17.58 ℃) and the initial melting temperature (23.97 ℃) decreased. This kind of MLCT with specific structure had potential structural and functional advantages, and provided research ideas for developing new MLCT. |
