甲壳低聚糖制备及其抗氧化活性研究

Study on Preparation of Chito-oligosaccharides and Its Antioxidant Activity

甲壳低聚糖是壳聚糖降解后的产物,其与壳聚糖相比分子量更小,水溶性更好,生物利用度更高。采用超声波协同α-淀粉酶处理壳聚糖制备甲壳低聚糖,以还原糖含量作为产品制备收得率的指标,通过正交实验优化制备工艺。结果表明,最佳工艺条件为:酶浓度1 000 U/g、酶解温度55℃、反应时间50 min、p H 5.2。在该条件下获得的降解产物还原糖浓度为2.25 mg/m L,制备效果优于单独超声波和酶解降解方法。对此方法制备的甲壳低聚糖的体外抗氧化活性进行研究,与抗坏血酸对比,其对DPPH自由基和超氧阴离子(O2-·)均有较强的清除能力。

Chito-oligosaccharides is the degradation product of Chitosan, which has small molecular weight, good water-soluble and a higher oavailability. In this experiment ehitosan was degraded by α-amylase under ultrasonic wave, measuring degradation effect with the index of reducing sugar concentration. The orthogonal experiments were conducted obtain the optimal hydrolysis conditions. The results showed that the optimal technological condition was as follows：amylase addition 1 600 U/g, enzymolysis temperature 55 ℃, enzymolysis time under ultrasonic wave 50 min and pH 5.2.In these conditions,the concentration of reducing sugar was determined to 2.25 mg/mL, and the effect was better than the preparation effect by ultrasonic method and enzymatic hydrolysis respectively. The antioxidative activities of chito-oligosaccharides prepared by this method were studied. The results showed that ehito-oligosaccharides demonstrated significant scavenging effects on DPPH and superoxide （O2 ^· ）compared with ascorbie acid.