Preparation, Properties And Application Of Antibacterial Film Based On Lysozyme Immobilized By N-succinyl-chitosan

N-succinyl chitosan(NCS)was synthesized by acylation of chitosan with succinic anhydride.FTIR and 'HNMR showed the reaction occurred on the amine group of chitosan,XRD indicated the degree of crystallization in NCS was weakened.Water-solubility of modified chitosan was improved due to the decrease of crystallization.Lysozyme immobilized by N-succinyl-chitosan(NSC-LSZ)was obtained under the optimized immobilization conditions of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride(EDC)20 mg,N-Hydroxysuccinimide(NHS)20 mg,lysozyme 100 mg,and p H 6.0.The amount of the NSC-LSZ was found to be89.04 %.The antimicrobial properties of NSC-LSZ retained excellent and safe for healthy by bacteriostatic test and LDH cytotoxicity test.The Secondary structure of the lysozyme immobilized by N-succinyl-chitosan had been changed thronugh characterized,such as FTIR and CD.Compared with NSC and LSZ,the thermostability of NSC-LSZ enhanced significantly.When the strawberry was coated with the coating solution of the NSC-LSZ under room temperature,the experiment results showed that the preservation time of strawberry could reach 6 days and extend 3 days.From results of the weight loss rate,texture,vitamin C content,p H of Strawberry,we could found that the NSC-LSZ had geat antibacterial effect and freshness.NSC-LSZ membranes were prepared based on casting and solvent evaporation method.Considering synthetically from multiple factors,the optimum conditions of the preparation of NSC-LSZ membrane was Glycerol 5 %(wt),drying time 7 h at40?.The obtained NSC-LSZ membrane had good water resistance,oxygen barrier,light transmittance,tensile strength,elongation and so on.