本文選題：微膠囊　切入點：緩釋　出處：《天津科技大學》2012年碩士論文

【摘要】：香精微膠囊化是利用天然或合成的高分子材料對香精進行包裹,既可以避免香精直接受光、熱的影響而引起氧化變質,又可以避免香精中有效成分的揮發(fā),有效控制香味物質的釋放,提高香味的穩(wěn)定性。分別采用離子交聯(lián)法和復凝聚法,利用殼聚糖和檸檬香精為主要原料,制備香精微膠囊。 微膠囊的粒徑大小和分布是微膠囊性能的一個重要指標,它不僅影響香精微膠囊的緩釋性能,也影響包覆隔離微膠囊的隔離性能。本實驗采用傅立葉變換紅外光譜儀、激光粒度分析儀、電子顯微鏡、多功能UV/VIS測定儀、熱重分析儀對香精微膠囊結構及性能進行了表征。 以三聚磷酸鈉為交聯(lián)劑,采用離子交聯(lián)法的原理制備了香精微膠囊。當殼聚糖質量濃度為2.4g/L,反應轉速和時間分別為800r/min和30min,芯壁比為4：1,m(香精)：m(乳化劑)=3：1,反應時pH值為5.1～6.0時,制備的微膠囊平均粒徑為13μm。 以檸檬香精為囊芯,殼聚糖和明膠為壁材,采用復凝聚法制備了香精微膠囊。當殼聚糖質量濃度為1g/L,明膠質量濃度為2g/L,復凝聚反應時pH值為6.0～6.5,系統(tǒng)溫度為40℃,乳化速率為700r/min,乳化時間為30min,芯壁比為7：1時,m(香精)：m(乳化劑)=4：1,制備的檸檬香精微膠囊固化前的平均粒徑為18μm,固化后的平均粒徑為91μm。 將不同濃度的微膠囊采用漿內添加法抄造手抄片,利用熱重分析儀對針葉木漿抄造的手抄片進行熱重分析,發(fā)現(xiàn)利用離子交聯(lián)法制備的微膠囊緩釋效果更好；檢測手抄片的物理性能并通過掃描電鏡觀察其形態(tài)結構,結果表明,當微膠囊添加量為2%時效果最佳,此時手抄片定量為80g/m2時,抗張指數(shù)為57.2N·m/g。 浸漬法比漿內添加法留香效果更加明顯。對浸漬法進一步改進,利用闊葉木漿通過調節(jié)不同打漿度、不同定量、不同浸漬時間抄造的手抄片,根據(jù)熱重分析,當打漿度為41°SR,定量為80g/m2,浸漬時間為1min時,手抄片中香精微膠囊的緩釋效果最佳,此時手抄片的抗張指數(shù)為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，

本文編號：1702975