Investigation On Preparation Process And Stability Of Lysozyme From Plateau Chicken Eggs White

Lysozyme, which is also known as a muramidase, is a hydrolase which has an effect on the microbe’s cell walls, with bacteriostasis, bacteriolysis, anti-inflammatory and anti-swelling characteristics, is widely used in the field of food preservation, modern medicine and biological research field, etc. Lysozyme was widely found in animals, plants and microorganisms, and the content of lysozyme was the highest in egg white. Enzyme activity of lysozyme in rare birds egg white is much higher than lysozyme in ordinary eggs, Rare birds eggs is more suitable as a production source of high quality. In this paper, we take rare birds eggs and cation exchange resin as raw material and aim to establish a process that suitable for industrialized production of rare birds egg lysozyme, process research is mainly divided as the following aspects:1) Selection of raw materials and resins for lysozyme extraction: The activity of lysozyme in egg white of 5 varieties and the adsorption effect of 5 kinds of cation exchange resins on lysozyme were investigated, and determined the plateau and weak acid cation exchange resin-D152 as raw material for preparation of lysozyme.2) Establishment of preparation process of lysozyme from Plateau chicken eggs: The process of preparation of lysozyme from plateau chiken egg was established. The optimum conditions of ion exchange method of lysozyme extraction was determined by orthogonal experiment: the volume ratio of ggg white and resin was 4:1, the dilution factor of egg white was 2 times, pH 9, stirring 3h was, and Na Cl solution with concentration of 1mol/L was used as the elution solution. The MWCO 5000 Da PES ultrafiltration membranes was used for removing salt and concentrating of lysozyme elution. Then drying of lysozyme concentrate by freeze-drying method. In this paper, the process is magnified 10 times to prepare lysozyme, the recovery of lysozyme was 0.44% the purity of lysozyme was 97%, and the enzyme activity was higher than 30000U/mg;3) Quality evaluation of plateau chicken egg lysozyme :The relative indicators of lysozyme were detected that prepared under the optimum conditions, The related indicators of lysozyme were in accordance with the national standards. This paper investigated the thermal stability of lysozyme at different temperatures, the preservation rate of lysozyme activity was 74% and 97% after preservating at 60℃ and-20℃ for 60 days,which proves that the thermal stability of lysozyme is good.