壳聚糖/琼脂糖双组份水凝胶的制备及其保湿缓释性能研究

Preparation of Chitosan/Agarose Two-Component Hydrogels and Its Water Holding and Sustained Release Properties

在1%的柠檬酸存在条件下,将一定量的壳聚糖和琼脂糖通过加热-冷却操作,本文成功制备了一类新型壳聚糖/琼脂糖双组份水凝胶。之后对该凝胶进行包括相变温度、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、流变学测试等一系列详细表征。研究表明壳聚糖比例越低、凝胶剂浓度越大,所制备的双组份水凝胶相变温度越高、稳定性越好。电镜结果表明该双组分凝胶材料具有疏松多孔的结构。随后将水凝胶冷冻干燥后制成干凝胶粉末,通过制粒技术将干凝胶粉末制备成干凝胶颗粒。在高温干燥环境下,干凝胶颗粒所吸附的水分可以逐步释放到环境中,从而起到持续、缓释保湿效果,在包装食品保湿、改善食品口味方面具有较好的应用前景。结合干凝胶颗粒水汽吸附实验和热重分析,本文提出了相应干凝胶颗粒的保湿机理。

Novel chitosan/agarose two-component hydrogels were successfully prepared using chitosan and agarose in the presence of1% citric acid and through a heating-cooling process.The resulting two-component hydrogels were characterized through the determination of phase transition temperature,scanning electron microscopy(SEM)analysis,transmission electron microscopy(TEM)analysis and rheological measurements.The obtained results showed that a lower proportion of chitosan and higher gelator concentration resulted in hydrogels with a higher phase transition temperature and higher stability.SEM and TEM analyses revealed that the hydrogels had a loose porous structure.Then, the hydrogels were freeze-dried and ground into powder,and such a xerogel powder was made into granules by a granulation technique.In a high temperature and dry environment,the water adsorbed by the xerogel granules was gradually released into the environment,thereby exhibiting a sustained and slow moisturizing effect,which has a good application prospect in keeping packaged food moisturized and improving food taste.The water retention and moisturizing mechanisms ofxerogel granules were proposed based on the water vapor adsorption experiment sand thermogravimetric analysis.