Abstract:Novel chitosan/agarose two-component hydrogels were successfully prepared using chitosan and agarose in the presence of 1% 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 of xerogel granules were proposed based on the water vapor adsorption experiment sand thermogravimetric analysis.
