Study On Antibacterial And Fresh Pork Preservation Effect Of Sodium Alginate Modified By Cold-plasma

Microbial spoilage was considered to be the main cause of spoilage in fresh prepared pork.In order to inhibit the spoilage of microorganisms,in addition to the standard production process,edible coating preservation was also an effective antibacterial preservation method to fresh prepared pork.Sodium alginate was biocompatibility and biodegradability and was easy to form film.Therefore,Sodium alginate can form a protective film on the surface of fresh pork.After cold plasma treatment,H2O2,O3,NO3-,NO2-and other bactericidal active substances were generated in sodium alginate solution so that sodium alginate aqueous solution was antibacterial.In this study,we used cold plasma to modify sodium alginate solution and analyzed its effect to improve the fresh-keeping period of fresh pork and determined its application possibility in food preservation as follows:1.Preparation and Antimicrobial of modified alginate edible coating by cold plasmaThe sodium alginate solution was used as the research object,and the function modification method of cold plasma to the sodium alginate solution was optimized by response surface experiment.Then,we analyzed the sterilization effect and long-acting bactericidal effect of modified sodium alginate on food-borne pathogenic bacteria and characterized its structure.The result showed that cold source plasma treatment voltage and treatment time had significant effect on the bactericidal effect of sodium alginate.Response surface test result showed that modified sodium alginate had the greatest sterilization effect on Escherichia coli(2.78±0.131gs)when the processing voltage was 73kv and the processing time was 4.5min.With the sterilization time increased,the sterilization effect of modified sodium alginate on Escherichia coli and Staphylococcus aureus was increased and the values was 7.06 and 3.08 1gs,respectively.Modified sodium alginate solution had long-term bactericidal effect,showing that the values of Escherichia coli and Staphylococcus aureus killed was 1.58 and 1.06 1gs,respectively,after being stored for 5 days.The result showed that there was no obvious effect on the film structure of sodium alginate before and after the cold plasma modifying.2.Study on effects of modified sodium alginate by cold plasma on fresh prepared pork preservationTaking fresh prepared pork as the research object,the effect of modified sodium alginate coatings on fresh prepared pork was studied.The result showed that the modified sodium alginate by cold plasma could significantly inhibit(P<0.05)the growth of Heat-killed loop fungi,Pseudomonas,Enterobacteriaceae,Staphylococcus during the storage of fresh prepared pork.In addition,modified sodium alginate could significantly(P<0.05)inhibit the TVB-N and maintain hardness in fresh prepared pork during storage.However,the modified sodium alginate could slightly cause the lipid oxidation of fresh prepared pork and reduce its redness.Compared with the control group,the modified sodium alginate by cold plasma could significantly(P<0.05)improve the sensory score of fresh prepared pork,and prolonged the shelf life of fresh prepared pork to 7 days.