Eco-friendly and non-toxic lysozyme immobilised on chitosan bacteriostatic agent for strawberry and fresh Tremella fuciformis preservation

Abstract

Safe and suitable food preservatives can ensure food safety and reduce resource wastage. This paper focuses on the modification of chitosan (CS) using 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)/laccase oxidation system and chitosanase. The experimental results showed that the aldehyde group content of the modified CS was increased by 83.3% and the water solubility increased by 4.5 times. In addition, the covalent binding with lysozyme (LSZ) also improved the inhibition effect and the diameter of the inhibition circle was increased by 3 mm. Applying the LSZ-modified CS to the preservation of strawberries and Tremella fuciformis (T. fuciformis), it was found that the preservation time of strawberries could be extended by 2 days at room temperature, and the microbial spoilage of T. fuciformis was also inhibited. This study provided a CS derivative that could be used as a carrier of natural antibacterial agents, which increased application scope of CS and provided a basis for antimicrobial preservation of food.