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| 利用Sn-2位富含多不饱和脂肪酸的改性椰子油制备低热量型有机凝胶及其特性研究 |
| Preparation and properties of a low-calorie organogel from modified coconut oil rich in polyunsaturated fatty acids at Sn-2 position |
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| DOI： |
| 中文关键词: 改性椰子油 有机凝胶 γ-谷维素 β-谷甾醇 Sn-2位脂肪酸 流变特性 |
| 英文关键词:modified coconut oil organogel β-sitosterol γ-oryzanol Sn-2 fatty acid rheological property |
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| 中文摘要: |
| 采用富含月桂酸的椰子油与富含多不饱和脂肪酸的鱼油为原料，对椰子油进行酶法改性，通过酯交换反应合成Sn-2位富含长链多不饱和脂肪酸（EPA,DHA）的结构脂。以此结构脂为基料油，γ-谷维素与β-谷甾醇的混合物作为凝胶剂制备油脂凝胶。以熔点和机械稳定性为指标，确定了γ-谷维素和β-谷甾醇制备结构脂凝胶油的最优工艺条件，并研究了油脂凝胶的质构、流变性质及微观形态。结果表明：改性椰子油Sn-2位的不饱和脂肪酸含量达到66.62%；制备油脂凝胶的最优工艺条件为γ-谷维素与β-谷甾醇质量比6∶?4、凝胶剂含量8%、加热温度90?℃、冷却温度5?℃。在最优工艺条件下，油脂凝胶的熔点为35?℃，机械稳定性达到95.3%，硬度为60.61 g，固体脂肪含量为1.33%。该油脂凝胶表现出假塑性流体特性，样品的表观黏度-剪切速率的关系符合幂律方程关系，在频率扫描范围内，油脂凝胶体系的G′明显大于G″，样品形成较为紧密的凝胶结构，具有较好的涂抹性和可塑性。样品微观网络结构分析表明，晶体呈现玫瑰状形态，形成了完整致密的三维超分子网络结构。 |
| 英文摘要: |
| Coconut oil rich in midium-chain fatty acids such as lauric acid and fish oil rich in polyunsaturated fatty acids were used to synthesize structure lipid rich in long-chain polyunsaturated fatty acids (EPA,DHA) at Sn-2 position by transesterification reaction. The organogel was prepared with the synthesized structure lipid as the base-material, and γ-oryzanol and β-sitosterol as the gels.Taking melting point and mechanical stability as the research objects, the optimal process conditions for the preparation of structure lipid organogel by β-sitosterol and γ-oryzanol were determined.The texture properties, rheological properties and microstructure of the structure lipid organogel were studied. The results indicated that the Sn-2 unsaturated fatty acid content in modified coconut oil reached 66.62%. The optimal conditions for preparing structure lipid organogel were obtained as follows: mass ratio of γ-oryzanol to β-sitosterol 6∶?4, gel content 8%, heating temperature 90?℃ and cooling temperature 5?℃. Under the optimal conditions, the melting point of organogel, mechanical stability, hardness and solid fat content were 35?℃，95.3%,60.61 g and 1.33%, repsc tively. The structure lipid organogel was pseudo plastic fluid, its relationship between the apparent viscosity and shearing rate conformed to the power law equation, and G′ of the organogel was significantly greater than G″ in the range of the frequency scanning which showed that relatively close structure was formed and the organogel had good spreadability and plasticity. The microstructure analysis of the sample showed that the crystal appeared rose-shaped, and a complete dense three-dimensional supermolecular network structure was formed. |
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