采用金属离子配位反应、硫化反应和包埋技术，制备壳聚糖型SO2缓释材料（Chitosan type SO2 sustained release material，CS-SO2SM），以期从分子结构着手研发出SO2新型葡萄保鲜剂。通过单因素实验，筛选最佳金属离子和硫化剂，结合析因实验设计，采用碘量法测定SO2释放量和抑菌圈试验测定其抑菌性；并以SO2释放曲线、释放天数为主要考察指标，抑菌性为辅助指标，优化CS-SO2SM的制备工艺；通过场发射环境扫描电子显微镜-能谱仪对其形态进行观察，傅里叶红外光谱仪考察其官能团的变化。最佳工艺为选择Cu2+，四硫化双五亚甲基秋兰姆（TRA）0.5 g，焦亚硫酸钠0.5 g，搅拌1.5 h，制备得到的CS-SO2SM为黑褐色粉末，电镜下为絮云状，主要官能团-OH、-NH、-CONH的特征吸收峰与壳聚糖相比均出现蓝移，SO2释放曲线呈先上升后缓慢下降。该条件下制备得到的材料抑菌圈平均直径为19.25 mm，具有最佳抑菌效果。研究表明通过配位反应、硫化反应及包埋技术制备而成的CS-SO2SM有望成为具有一定应用前景的SO2新型保鲜剂。
In this study, chitosan-type SO2 sustained-release material (CS-SO2SM) was prepared by metal ion complexation reaction, vulcanization reaction and embedding technology, in order to develop a new SO2 preservative for grapes based on molecular structure. Through single factor experiments, the best metal ion(s) and vulcanizing agent(s) were screened. In combination with the factorial experiment design, the amount of released SO2 and the antibacterial activity were determined by the iodometric method and inhibition zone test, respectively. The preparation process of CS-SO2SM was optimized through taking the SO2 release curve and release days as the main examination indices. Its morphology was observed by the field emission environmental scanning electron microscope-energy spectrometer, and the changes of its functional groups were examined by a Fourier infrared spectrometer. The optimal process conditions: Cu2+ as the metal ion, 0.5 g of dipentamethylenethiuram tetrasulfide (TRA), 0.5 g of sodium pyrosulfite, and preparation duration (with stirring) as 1.5 h. The prepared CS-SO2SM was a dark brown powder which appeared as flocculated clouds under the electron microscope. The characteristic absorption peaks of the main functional groups, -OH, -NH and -CONH showed blue shifts compared with chitosan. The SO2 release curve showed a rise first and then a slow decline. The materials prepared under these conditions had an average diameter of 19.25 mm for the inhibition zone and exhibited the strongest antibacterial effect. The research has shown that CS-SO2SM prepared by coordination reaction, vulcanization reaction and embedding technology is expected to be a new type of SO2 preservative with a certain application prospect.