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| 酶催化分子蒸馏单甘酯的重相产物制备中、长链甘油二酯及其性质研究 |
| Enzymatic production and characterization of medium- and long- chain diglycerides from residue phase products of molecular distillated monoacylglycerols |
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| DOI： |
| 中文关键词: 重相产物 中、长链甘油二酯 分离纯化 热力学性质 晶型特性 |
| 英文关键词:molecular distillation residue(MDR) medium- and long- chain diglycerides(M/LCD) separation and purification thermodynamic property crystal characteristics |
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| 中文摘要: |
| 以分子蒸馏单甘酯的重相产物和辛酸为原料，固定化脂肪酶Lipozyme TL IM为催化剂催化酯交换反应制备中、长链甘油酯（M/LCG）。通过单因素实验探究了底物（重相产物与辛酸）摩尔比、反应温度、反应时间、加酶量对产品中含有辛酸的甘油酯成分含量及辛酸插入率的影响，从而选择合适的工艺条件为：反应温度65?℃，底物摩尔比6∶?4，反应时间6 h，加酶量15%。在选定条件下，产品M/LCG中甘油二酯（DAG）含量为50.73%，辛酸插入率为15.35%。对选定条件下的M/LCG样品经柱层析分离纯化，以硅胶为吸附剂，正己烷-乙醚-甲酸（体积比45∶?25∶?1）的溶液为洗脱剂，可得到DAG含量为88.24%的中、长链甘油二酯（M/LCD），且主要为sn-1,3 DAG。通过DSC、XRD对纯化的M/LCD进行性质研究，测得其熔点为60.34?℃，存在明显同质多晶现象，主要为β与β′晶型共存。M/LCD的热力学性质以及晶型特性将为其在乳液方面的潜在应用提供一定的理论依据。 |
| 英文摘要: |
| The medium- and long- chain glycerides (M/LCG) were prepared by enzymatic transesterification of octanoic acid and molecular distillation residue of monoglyceride with Lipozyme TL IM as catalyst. The effects of molar ratio of substrate (molecular distillation residue and octanoic acid), reaction temperature, reaction time and dosage of enzyme on the content of octanoic acid-containing glycerides and the entrapment efficiency of octanoic acid were investigated by single factor experiment. And the optimal process conditions were obtained as follows: reaction temperature 65?℃, molar ratio of molecular distillation residue to octanoic acid 6∶?4, reaction time 6 h and dosage of enzyme 15%. Under the optimal conditions, the content of diglycerides in M/LCG was 50.73%,and the entrapment efficiency of octanoic acid was 15.35%. The M/LCG obtained by optimal conditions was purified by column chromatography with silica gel as adsorbent, n-hexane-ether-formic acid (volume ratio 45∶?25∶?1) as eluent, and medium- and long- chain diglycerides (M/LCD) with DAG content 88.24% was obtained, and main were sn-1,3 DAG. The characteristics of the purified M/LCD was measured by DSC and XRD, and the results showed the melting point of M/LCD was 60.34?℃, and there was obvious polymorphisms, mainly coexistence of β and β′ type crystal form. The thermodynamic properties and crystal form of M/LCD would provide a certain theoretical basis for its potential application in emulsion. |
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