微胶囊化柿单宁的制备及性质分析

Preparation and Property Analysis of Microencapsulated Persimmon Tannin

用辛烯基琥珀酸淀粉酯和大豆分离蛋白作为复合壁材,采用喷雾干燥技术,对柿单宁进行微胶囊,从包埋率和经济条件考虑,壁材和芯材的比例为20:1(m/m)为最佳。微胶囊包埋率为94.3%,包埋产率为92.4%。正交实验所得制备微胶囊最佳条件为进风温度388 K、进料速率3.0×10^(-3) L/s、风机0.050 m^3/s,此条件下的实验集粉率为92.03%。通过微胶囊粒度分析、扫描电镜、红外光谱分析可知,复合壁材和柿单宁存在包埋作用,微胶囊表现出壁材的特性。理化性质分析表明:微胶囊化使单宁的水溶性增加了10倍;微胶囊单宁受到壁材的保护仍然表现出很大的抗氧化能力和清除DPPH自由基能力,且在水溶液体系中的稳定性大大提高;微胶囊在能很好地在胃液和肠道释放,且肠道释放效果比胃液好,在40 min可以释放80%左右。

Using octenyl succinic acid-modified starch and soybean protein isolate as composite wall materials, microencapsulated persimmon tannin was prepared by spray drying. In terms of the embedding rate and cost, the optimum proportion of wall material and core material was 20：1（m/m）. The embedding rate of microcapsules was 94.3%, and the embedding yield was 92.4%. By orthogonal experiment, the optimum conditions for the preparation of microcapsules were as follows： inlet air temperature 388 k, feeding rate 3.0×10-3 L/s, and blower flow rate 0.050 m3/s. Under these conditions, the powder collection rate was 92.03%. Microcapsule particle size analysis, scanning electron microscopy, and infrared spectrum analysis revealed that an embedding effect existed in the composite wall materials and persimmon tannins, and the microcapsules exhibited the characteristics of the wall material. Physiochemical property analysis demonstrated that the water solubility of tannin was increased by 10 times after microencapsulation; with the protection from the wall material, the microencapsulated persimmon tannin retained a strong antioxidant activity and 2,2-diphenyl-1-picrylhydrazyl（DPPH） free radical scavenging ability, and its stability in aqueous solution was improved significantly. The microencapsulated persimmon tannin could be released in gastric juice and the intestinal tract,and the intestinal release effect was better than that in gastric juice, with a release rate of 80% within 40 min.