可食用果蔬保鲜剂CTS-cys的合成

Synthesis of Edible Antistaling Agent CTS-cys for Fruits and Vegetables

摘要: 利用壳聚糖(CTS)良好的成膜，抑菌性和L-半胱氨酸(L-cys)良好的抑菌，抗氧化性，通过化学改性法制备了巯基含量高达333 μmol/g的L-cys改性CTS (CTS-cys)。采用抑菌圈法研究了CTS、L-cys和CTS-cys对大肠杆菌、蜡样芽孢杆菌和金黄色葡萄球菌的抑菌效果。实验结果表明：在被测试范围内，L-cys对三种菌株均有很好抑菌性；CTS-cys对大肠杆菌、金黄色葡萄球菌均有较好抑菌效果，最大抑菌率为89%，92.9%，对蜡样芽孢杆菌的最大抑菌率只有60.5%；CTS对三种菌株的最大抑菌率均在50%水平以下，抑菌效果差。壳聚糖半胱氨酸衍生物很大程度上协同了半胱氨酸的抑菌性，大大提高了壳聚糖的抑菌能力。

Abstract: The L-cys modified CTS (CTS-cys) with the content of thiol up to 333 μmol/g was prepared by chemical modification, which made use of good film formation, bacteriostasis of chitosan (CTS) and good antibacterial, antioxidant of L-cysteine (L-cys). The inhibitory effects of CTS, L-cys and CTS-cys on Escherichia coli, Bacillus cereus and Staphylococcus aureus were studied by the method of inhibition zone. The experimental results as follows: L-cys had good antibacterial activity to the three strains in the tested range; CTS-cys had good antibacterial effect on Escherichia coli and Staphylococcus aureus and the maximum inhibition rate was 89%, 92.9%, while the maximum inhibition rate of CTS-cys against Bacillus cereus was only 60.5%. The maximum inhibition rate of CTS to three strains was lower than 50%, and the inhibitory effect was poor. Chitosan cysteine derivatives have largely coordinated the bacteriostasis of cysteine and greatly enhanced the bacteriostatic ability of chitosan.