Lipozyme RM IM-catalyzed acidolysis of Cinnamomum camphora seed oil with oleic acid to produce human milk fat substitutes enriched in medium-chain fatty acids.
Lipozyme RM IM-catalyzed acidolysis of Cinnamomum camphora seed oil with oleic acid to produce human milk fat substitutes enriched in medium-chain fatty acids.
复制标题
DOI：
10.1021/jf503691p
复制
发表时间：
2014-10
影响因子：
6.1
通讯作者：
Xian-Guo Zou;Jiang-Ning Hu;Man-Li Zhao;Xue-mei Zhu;Hong-yan Li;Xiaoru Liu;Rong Liu;Z. Deng
中科院分区：
文献类型：
--
作者：
Xian-Guo Zou;Jiang-Ning Hu;Man-Li Zhao;Xue-mei Zhu;Hong-yan Li;Xiaoru Liu;Rong Liu;Z. Deng
以肉桂籽油（CCSO）和油酸为原料，在无溶剂体系中通过酸解反应合成富含中链脂肪酸（MCFA）的人乳脂肪替代品（HMFS）。以米黑根毛霉（Rhizomucormiehei）的固定化脂肪酶LipozymeRM IM为生物催化剂。采用响应面法（RSM）考察了底物摩尔比、酶浓度、反应温度和反应时间等因素对油酸掺入量的影响，确定了油酸掺入量的最佳值。优化后的结果表明，油酸在HMFS中的最大掺入率为59.68%。与CCSO相比，HMFS中sn-2位的中链脂肪酸占70%以上，而油酸主要位于sn-1，3位（78.69%）。同时，HMFS中的三酰甘油（TAG）组分主要为OCO（23.93%）、CCO（14.94%）、LaCO（13.58%）、OLaO（12.66%）和OOO（11.13%）。最终确定的最佳反应条件为：底物摩尔比（油酸/CCSO）为5：1，酶浓度为12.5%（w/w总反应物），反应温度为60 °C，反应时间为28 h。还评价了Lipozyme RM IM在酸解反应中的可重复使用性，发现其可重复使用多达9次而没有显著的活性损失。采用尿素包合法对合成产物进行分离纯化。随着HMFS/尿素比例增加到1：2，酸值降低到最低。在放大实验中，HMFS（改良CCSO）中TAG和总生育酚的含量分别为77.28%和12.27 mg/100 g。纯化后的产品各项理化指标均符合食品标准。因此，这种通过使用酸解方法生产的富含MCFA的HMFS可能在婴儿配方食品工业中具有潜在的应用。
In the present study, a human milk fat substitute (HMFS) enriched in medium-chain fatty acids (MCFAs) was synthesized through acidolysis reaction from Cinnamomum camphora seed oil (CCSO) with oleic acid in a solvent-free system. A commercial immobilized lipase, Lipozyme RM IM, from Rhizomucor miehei, was facilitated as a biocatalyst. Effects of different reaction conditions, including substrate molar ratio, enzyme concentration, reaction temperature, and reaction time were investigated using response surface methodology (RSM) to obtain the optimal oleic acid incorporation. After optimization, results showed that the maximal incorporation of oleic acid into HMFS was 59.68%. Compared with CCSO, medium-chain fatty acids at the sn-2 position of HMFS accounted for >70%, whereas oleic acid was occupied predominantly at the sn-1,3 position (78.69%). Meanwhile, triacylglycerol (TAG) components of OCO (23.93%), CCO (14.94%), LaCO (13.58%), OLaO (12.66%), and OOO (11.13%) were determined as the major TAG species in HMFS. The final optimal reaction conditions were carried out as follows: substrate molar ratio (oleic acid/CCSO), 5:1; enzyme concentration, 12.5% (w/w total reactants); reaction temperature, 60 °C; and reaction time, 28 h. The reusability of Lipozyme RM IM in the acidolysis reaction was also evaluated, and it was found that it could be reused up to 9 times without significant loss of activities. Urea inclusion method was used to separate and purify the synthetic product. As the ratio of HMFS/urea increased to 1:2, the acid value lowered to the minimum. In a scale-up experiment, the contents of TAG and total tocopherols in HMFS (modified CCSO) were 77.28% and 12.27 mg/100 g, respectively. All of the physicochemical indices of purified product were within food standards. Therefore, such a MCFA-enriched HMFS produced by using the acidolysis method might have potential application in the infant formula industry.