Lipase-catalyzed synthesis of human milk fat substitutes from palm stearin in a continuous packed bed reactor.

摘要

Structured lipids (SL) with similar fatty acid (FA) composition and distribution to human milk fat (HMF) were synthesized by lipase-catalyzed acidolysis of chemically interesterified palm stearin (IV = 35.6) with mixed FA of stearic acid and myristic acid and FA from rapeseed oil, sunflower oil, and palm kernel oil in a continuous packed bed reactor. Response surface methodology (RSM) was used to optimize the reaction system with three selected parameters, namely residence time, temperature, and substrate molar ratio. The best-fitting quadratic models were obtained for the contents of palmitic acid (PA) and PA at the sn-2 position (sn-2 PA) by multiple regressions and the determination coefficient (R2) values for the models were 0.9886 and 0.9799, respectively. The optimal conditions generated from the models were as follows: residence time, 2.7 h; temperature, 58 degrees C; substrate molar ratio, 9.5 mol/mol. Under these conditions, the contents of PA and sn-2 PA were 28.8 and 53.2%, respectively, and other FA observed in the experiments were all within the range of corresponding FA of HMF. The similarity of the product obtained to HMF was evaluated by the cited model. The scores for total and sn-2 FA of the product were 45.2 and 38.4, respectively, and the total score for the product was 83.6, which indicated a high degree of similarity of the product to HMF