To investigate the effect of carboxymethylated with different degrees of substitution on the properties of Siraitia grosvenorii polysaccharide (SGP), carboxymethylated Siraitia grosvenorii polysaccharide (CSGP) was prepared by solvent method by using the raw material of SGP. The effects of chloroacetic acid concentration, reaction time, and sodium hydroxide concentration on the degree of substitution were analyzed, and the CSGP with the degree of substitution ranging from 0.28 to 1.09 was prepared. The physicochemical properties of CSGP with different substitution degrees were characterized, and the effects of substitution degrees on hypoglycemic activity and antioxidant activity were investigated by in vitro physiological activity experiments. The high-performance gel permeation chromatography revealed that the molecular mass of CSGP was smaller than that of SGP. The results of FTIR manifested a new absorption peak at 1317 cm−1, indicating that carboxymethyl was successfully introduced into the polysaccharide. The results of scanning electron microscopy showed that with the increase of substitution degree, the surface morphology of CSGP became more fragmented and appeared to curl. Congo red experiment revealed that the triple helix structure of CSGP with high substitution degree disappeared. In vitro physiological activity experiment showed that 6 mg/mL of the CSGP-M had the highest α-amylase inhibition, DPPH, and hydroxyl radical scavenging rates of 44.36%±1.30%, 63.17%±2.07%, and 70.21%±1.89%, respectively. Compared with SGP, CSGP-L and CSGP-H, CSGP-M with medium degree of substitution has the best hypoglycemic activity and antioxidant activity in vitro. When the degree of substitution was increased to 1.09, the inhibition rate of α-amylase, DPPH and hydroxyl radical scavenging rate of CSGP-H decreased to 11.65%±0.26%, 47.45%±0.79%, and 34.85%±0.78%, respectively. The results indicated that CSGP with medium degree of substitution could exert the best physiological activity.

为提高槐米芦丁在人体内的肠道吸收率,以槐米芦丁为芯材,明胶、羧甲基淀粉为壁材,采用复凝聚法制备槐米芦丁微胶囊.以成囊效果为参考,结合壁材的带电性质和体系浊度分析,考察壁材浓度和壁材质量比(明胶∶羧甲基淀粉)工艺参数对复凝聚反应的影响.以包埋率和产率为指标,通过单因素试验,比较分析复凝聚反应的芯壁质量比、反应温度、反应时间及转谷氦酰胺酶添加量因素对微胶囊包埋效果的影响,并通过响应面试验对反应的芯壁质量比、反应温度和反应时间因素进行工艺优化.结果表明,槐米芦丁微胶囊最佳工艺为:壁材浓度为1.50％、壁材质量比为10∶1、体系pH4.5、芯壁质量比1∶51.8、反应温度39.6℃、反应时间32 min、转谷氨酰胺酶添加量20g/100g明胶,此条件下微胶囊包埋率为(90.93±0.19)％,平均粒径为103.3μm.槐米芦丁微胶囊化的研究拓宽了槐米芦丁的应用范围.