肉桂精油/海藻酸钠/膨润土复合凝胶微球的制备及缓释研究

以海藻酸钠/膨润土(Sodium alginate/Bentonite,SA/BT)共混改性后的复合材料为载体,采用挤出外源凝胶法制备装载肉桂精油的凝胶微球,探究海藻酸钠浓度、膨润土添加量、肉桂精油与载体的比例、CaCl₂浓度、tween-80浓度对凝胶微球包封率的影响,并优化其制备工艺。同时在不同温度和湿度下进行凝胶微球的释放实验,并用零级,一级,Ritger-Peppas,Hixson-Crowell等动力学模型拟合肉桂精油的释放曲线。结果表明,最佳的制备条件为海藻酸钠浓度2%,膨润土添加量1.1%,肉桂精油与载体的比例2.1:1,CaCl₂浓度1.5%,tween-80浓度0.2%,包封率可达80.74%。在不同温度(25、40、60、80 ℃)和相对湿度(55%,75%,90%)下,海藻酸钠/膨润土复合凝胶微球释放肉桂精油速率均低于单一海藻酸钠凝胶微球,同时发现Ritger-Peppas动力学模型更符合肉桂精油在不同条件下的释放规律,为肉桂精油更广泛的应用提供了一定的理论依据,提高了其应用价值。

Preparation and Sustained Release Behavior of Cinnamon Essential Oil/ Sodium Alginate/Bentonite Composite Gel Microspheres

Used sodium alginate/bentonite (SA/BT) blend modified composite as a carrier, gel microspheres loaded with cinnamon essential oil were prepared by extruded exogenous gel method. Then factors influencing the encapsulation rate of gel microspheres were investigated, including sodium alginate concentration, bentonite addition, ratio of cinnamon essential oil to carrier, CaCl₂ concentration, tween-80 concentration. At the same time, the preparation process was optimized. Then, gel microspheres were released at different temperatures and humidity, and the release curves of cinnamon essential oil were fitted with Zero-order, First-order, Ritger-peppas, Hixson-crowell and other kinetic models. The experimental results showed that the optimal preparation conditions were sodium alginate concentration of 2%, bentonite content of 1.1%, cinnamon essential oil to carrier ratio of 2.1:1, CaCl₂ concentration of 1.5%, tween-80 concentration of 0.2%, and encapsulation rate of up to 80.74%. At different temperatures (25, 40, 60, 80℃) and relative humidity (55%, 75%, 90%), the release rate of cinnamon essential oil by sodium alginate/bentonite composite gel microspheres was lower than that by single alginate gel microspheres. Meanwhile, it was found that Ritger-Peppas kinetic model was more consistent with the release law of cinnamon essential oil under different conditions. The results would provide a certain theoretical basis for the wider application of cinnamon essential oil and improve its application value.