Study On Biosecurity Of Lysozyme Liposomes And The Effect On Trachinotus Ovatus Preservation

Lysozymehave shown high effective antibacterial function,so it is applied in the food industry widely as natural preservative.However,lysozyme is easily affected by environment factor,leading to the limit of lysozyme application greatly.Liposomes can improve the stability and bioavailability of the lysozyme.Besides,due to its unique small size effect and quantum effect,which enable the drug to become fullybiological function.In this study,we prepared lysozyme to lysozyme liposomes by reverse-phase evaporation method,studythe best preparation programs of the lysozyme liposomes,assessment its stability,fat soluble,slow-releasing potential,antimicrobial activity of lysozyme liposomes.We explore its fresh-keeping effect on fresh Trachinotus ovatus.Finally,organic reagent residues were measured by Headspace gas chromatography and MTT methods was used to observe the cell inhibiting.Specific results are as follows:(1)Through the single factor and response surface experiments,the optimum formulation was as follows: cholesterol to lipid ratio of 3.9:1(mg/mg),lysozyme concentration of 2.0 mg/m L,ultrasound time of 14.2 min,magnetic stirring time of 40.6 min.And in this condition,the prepared lysozyme liposomes have the highest encapsulation efficiency of 75.4%±3.3%,the particle size was 245.6 nm±5.2 nm,polydispersity index(PDI)was 0.174±0.007.Scanning electron micrographs revealed that the lysozyme liposomes had a regular spherical shape and formed and agglomerated in a fully spread manner.At the first 4 hours of release,lysozyme liposomes released with accumulative released rate of 30%.After that release rate of lysozyme liposome was slow down with accumulative rate of 100% in 18 h.The solubility of the lysozyme liposomes in rapeseed salad oil was over 1g/100 g.The results show the good fat soluble capacity of the lysozyme liposomes.(2)With the storage time increases,the lipid of the lysozymes liposomes gradually oxidized,leading to the particle size gradually increase and the p H descending,in 0~7 d relatively stable;in the simulated gastrointestinal fluid within 0~1 h,the leakage rate gradually increased and stabilized at 5 h;the optimal temperature for lysozyme liposomes is 4 to 40 ?;the vitro antibacterial activity showed that lysozyme liposomes presented a significant inhibitory effect on Listeria monocytogenes(3)To determin ether and chloroform in the lysozyme liposomes by headspace gas chromatography,residues of the sample after testing were less than 0.006%.And the MTT experiment results suggest that the prepared lysozyme liposomes showed goodbiosafety and can be suitable for food industry and other industries.(4)Using sensory evaluation,p H,TBA,total number of bacterial colony and TVBN as indicators,we investigate the effects of lysozyme on Trachinotus ovatus preservation at 4 ?.Fresh Trachinotus ovatus was selected as material and to obtain the rough digestive to assess the protective effect of the liposomes.Experiments showed that lysozyme liposomes effectively checks the increase of p H,TBA,TVB-N values,maintain sensory evaluation scores,and inhibited microbial growth.Compared with lysozyme,lysozyme liposomes have good results on Trachinotus ovatus.Liposomes could provide effective protection for lysozyme against a series of digestive.