缓释香精微胶囊的制备及其在装饰纸中的应用

发布时间：2018-04-03 01:18

  本文选题：微胶囊　切入点：缓释　出处：《天津科技大学》2012年硕士论文

【摘要】：香精微胶囊化是利用天然或合成的高分子材料对香精进行包裹,既可以避免香精直接受光、热的影响而引起氧化变质,又可以避免香精中有效成分的挥发,有效控制香味物质的释放,提高香味的稳定性。分别采用离子交联法和复凝聚法,利用壳聚糖和柠檬香精为主要原料,制备香精微胶囊。 微胶囊的粒径大小和分布是微胶囊性能的一个重要指标,它不仅影响香精微胶囊的缓释性能,也影响包覆隔离微胶囊的隔离性能。本实验采用傅立叶变换红外光谱仪、激光粒度分析仪、电子显微镜、多功能UV/VIS测定仪、热重分析仪对香精微胶囊结构及性能进行了表征。 以三聚磷酸钠为交联剂,采用离子交联法的原理制备了香精微胶囊。当壳聚糖质量浓度为2.4g/L,反应转速和时间分别为800r/min和30min,芯壁比为4：1,m(香精)：m(乳化剂)=3：1,反应时pH值为5.1～6.0时,制备的微胶囊平均粒径为13μm。 以柠檬香精为囊芯,壳聚糖和明胶为壁材,采用复凝聚法制备了香精微胶囊。当壳聚糖质量浓度为1g/L,明胶质量浓度为2g/L,复凝聚反应时pH值为6.0～6.5,系统温度为40℃,乳化速率为700r/min,乳化时间为30min,芯壁比为7：1时,m(香精)：m(乳化剂)=4：1,制备的柠檬香精微胶囊固化前的平均粒径为18μm,固化后的平均粒径为91μm。 将不同浓度的微胶囊采用浆内添加法抄造手抄片,利用热重分析仪对针叶木浆抄造的手抄片进行热重分析,发现利用离子交联法制备的微胶囊缓释效果更好；检测手抄片的物理性能并通过扫描电镜观察其形态结构,结果表明,当微胶囊添加量为2%时效果最佳,此时手抄片定量为80g/m2时,抗张指数为57.2N·m/g。 浸渍法比浆内添加法留香效果更加明显。对浸渍法进一步改进,利用阔叶木浆通过调节不同打浆度、不同定量、不同浸渍时间抄造的手抄片,根据热重分析,当打浆度为41°SR,定量为80g/m2,浸渍时间为1min时,手抄片中香精微胶囊的缓释效果最佳,此时手抄片的抗张指数为39.9N·m/g。
[Abstract]:Essence microencapsulation is the use of natural or synthetic polymer materials to wrap the essence, can not only avoid the direct influence of light, heat and oxidative deterioration, but also avoid volatile components in the essence.Effectively control the release of aroma substances, improve the stability of the aroma.The microcapsules were prepared by ion crosslinking method and complex condensation method, using chitosan and lemon essence as the main raw materials.The size and distribution of microcapsules is an important index of the performance of microcapsules. It not only affects the sustained release performance of microcapsules, but also affects the isolation performance of encapsulated microcapsules.The structure and properties of microcapsules were characterized by Fourier transform infrared spectrometer, laser particle size analyzer, electron microscope, multifunction UV/VIS analyzer and thermogravimetric analyzer.Using sodium tripolyphosphate as crosslinking agent, the essence microcapsules were prepared by ion crosslinking method.When the mass concentration of chitosan was 2.4 g / L, the reaction speed and time were 800r/min and 30 min, the core / wall ratio was 4: 1 / m (emulsifier 3: 1, pH = 5.1), the average diameter of the microcapsules was 13 渭 m.Using lemon essence as the capsule core, chitosan and gelatin as wall materials, microcapsules of essence were prepared by complex condensation method.When the mass concentration of chitosan is 1 g / L, the mass concentration of gelatin is 2 g / L, the pH value is 6.0 ~ 6.5, and the system temperature is 40 鈩，

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