高粱醇溶蛋白–壳聚糖复合精油载体的性能研究

Performance Study of Kafirin-Chitosan Composite Essential Oil Carrier

摘要: 高粱醇溶蛋白(Kaf)是一种植物蛋白，可溶解于一定浓度的乙醇水溶液中。借助其独特的溶解性，可以通过反溶剂的方法在水中自组装形成纳米粒子，常用于包封生物活性物质以形成缓释效果。本论文以高粱粉为原料，通过超声波–微波辅助法提取出Kaf，并通过溶胶–凝胶法生成壳聚糖(CS)/Kaf复合载体。为了进一步研究复合载体对精油的负载、缓释性能，引入了植物精油L-薄荷醇(Mel)作为抑菌剂，最后通过真空冷冻干燥工艺制备了CS/Kaf/Mel复合气凝胶。利用SEM、FTIR来表征复合气凝胶的微观形貌和组成；利用万能试验机测试了气凝胶的力学性能；利用GC-MS和气凝胶释放性能实验等测试了复合气凝胶中Mel的包封率、负载率和释放性能。结果表明复合气凝胶中Kaf为球状形貌，并在进行释放后球状形貌从闭合状变为开口或塌陷状，说明复合气凝胶成功负载了Mel；Kaf的加入使得复合气凝胶力学性能提升显著，压缩模量最大提升了70%；随着CS/Kaf比例的增大，Mel的包封率和负载率先升高后减小，最大负载率为3.1%；缓释实验结果表明复合气凝胶中Mel第12天释放量从78.12%降到了61%，表明CS/Kaf复合气凝胶对Mel具有良好的缓释效果。

Abstract: Kafirin (Kaf) is a plant protein that can be solubilised in aqueous ethanol solutions at certain concentrations. With its unique solubility, it can be self-assembled in water by an anti-solvent method to form nanoparticles, which are commonly used to encapsulate bioactive to create a slow-release effect. In this thesis, Kaf was extracted from sorghum powder by ultrasonic-microwave-assisted method and chitosan (CS)/Kaf composite carrier was generated by sol-gel method. In order to further investigate the loading and slow-release performance of the composite carrier on essential oils, L-menthol (Mel), a plant essential oil, was introduced as a bacteriostatic agent, and finally the CS/Kaf/Mel composite aerogel was prepared by vacuum freeze- drying process. SEM and FTIR were used to characterise the microscopic morphology and composition of the composite aerogel; the mechanical properties of the aerogel were tested using a universal testing machine; and the encapsulation rate, loading rate and release properties of Mel in the composite aerogel were tested using GC-MS and aerogel release performance experiments. The results showed that the Kaf in the composite aerogel was spherical, and the spherical shape changed from closed to open or collapsed after release, indicating that the composite aerogel was successfully loaded with Mel; the addition of Kaf made the mechanical properties of the composite aerogel improve significantly, and the compression modulus increased by a maximum of 70%; the encapsulation rate and the loading rate of Mel increased and then decreased with the increase of the ratio of CS/Kaf, with the maximum loading rate of 3%. With the increase of the CS/Kaf ratio, the encapsulation rate and loading of Mel increased firstly and then decreased, the maximum loading rate was 3.1%; the results of the slow-release experiment showed that the release of Mel in the composite aerogel on the 12th day decreased from 78.12% to 61%, which indicated that the CS/Kaf composite aerogel had a good slow-release effect on Mel.