Kotani Kousuke, Yamamoto Yukihiro, Hara Setsuko
Faculty of Science and Technology, Seikei University.
J Oleo Sci. 2015;64(3):275-81. doi: 10.5650/jos.ess14254.
Human milk fat substitutes (HMFSs), rich in palmitic acid (P) at the sn-2 position of triacylglycerol (TAG), were prepared from lard via Novozym435(®)- and Lipozyme RM-IM(®)-mediated two-step reactions. First, 2-palmitoyl monoacylglycerol (2-P-MAG, 90% purity) was prepared via Novozym435(®)mediated ethanolysis of lard. Then, 2-P-MAG, oleic acid (O), linoleic acid (L), and lard were dissolved in hexane and subjected to a Lipozyme RM-IM(®)-mediated reaction for HMFS preparation. The effect of the amount of 2-P-MAG and fatty acids (O and L) in HMFS preparation were investigated. Under the optimum reaction conditions: 7 mmol of lard, 3.0 mmol of 2-P-MAG, 5.2 mmol of O, 3.5 mmol of L, 10 mL of hexane, 10 wt% of Lipozyme RM-IMR(®) (against the total weight of substrates), 550 rpm, 37°C and 6 h, a HMFS with total fatty acid composition and P content at the sn-2 position of TAG similar to that of human milk fat was prepared. In the same way, a HMFS having polyunsaturated fatty acids (PUFA) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (PUFA-HMFS) was prepared. The HMFS and PUFA-HMFS prepared in this study, as well as fats extracted from commercially available powdered milk for infants (FPM) were evaluated for their oxidation stability by an auto-oxidation test. The test showed HMFS and PUFA-HMFS to possess greater oxidation stability than that the FPMs. These results indicated that the HMFS and PUFA-HMFS prepared in this study have value as potential ingredients for powdered milk.
人乳脂肪替代品（HMFSs）富含位于三酰甘油（TAG）sn-2位的棕榈酸（P），是通过诺维信435（®）和脂肪酶RM-IM（®）介导的两步反应由猪油制备而成。首先，通过诺维信435（®）介导的猪油乙醇解反应制备2-棕榈酰单酰甘油（2-P-MAG，纯度90%）。然后，将2-P-MAG、油酸（O）、亚油酸（L）和猪油溶解在己烷中，并进行脂肪酶RM-IM（®）介导的反应以制备HMFS。研究了2-P-MAG和脂肪酸（O和L）的用量对HMFS制备的影响。在最佳反应条件下：7 mmol猪油、3.0 mmol 2-P-MAG、5.2 mmol O、3.5 mmol L、10 mL己烷、10 wt%脂肪酶RM-IMR（®）（相对于底物总重量）、550 rpm、37°C和6 h，制备出了TAG的总脂肪酸组成和sn-2位P含量与人乳脂肪相似的HMFS。同样地，制备出了含有二十碳五烯酸（EPA）和二十二碳六烯酸（DHA）等多不饱和脂肪酸（PUFA）的HMFS（PUFA-HMFS）。通过自动氧化试验对本研究中制备的HMFS和PUFA-HMFS以及从市售婴儿奶粉中提取的脂肪（FPM）的氧化稳定性进行了评估。试验表明，HMFS和PUFA-HMFS的氧化稳定性高于FPM。这些结果表明，本研究中制备的HMFS和PUFA-HMFS作为婴儿奶粉的潜在成分具有价值。
