Research On The Safe Control Technology Of Cold Chain Of Fresh And Wet Surface Ozone Sterilization And Natural Antibacterial Agent

Noodles,the staple food represented by noodles,always occupy a dominant position in the diet consumption structure of urban and rural areas in China.Compared with Fried instant noodles,fresh and wet noodles can better meet the healthy and nutritious diet needs of consumers.In the green consumption concept is more and more popular today,fresh wet noodles as a new generation of convenience food is more and more popular with consumers.However,due to the high water content and rich nutrition of fresh and wet noodles,it is very easy to cause the growth and reproduction of harmful microorganisms,leading to the deterioration of noodles,so the short shelf life has been the bottleneck of the industrial production of fresh noodles;At the same time,as fresh noodles belong to convenience food,the problem of pathogen contamination has been widely concerned.Selected staphylococcus aureus for exogenous pollution indicator bacteria,with the fresh face wet as the research object,in the process of cold chain based on ozone sterilization and food grade natural bacteriostatic agent,setting up a comprehensive ozone sterilization-natural bacteriostat preservation and safety control technology,through to the shelf life of cold chain to evaluate quality and microorganism index,optimization based cold-chain fresh face wet harmful microbes security control and key technologies;After the fresh and wet surface was made under control conditions,the genomic DNA of microbial flora was extracted from the fresh and wet surface at each storage stage and at each temperature.The 16S universal primer was used to expand the DNA library,and high-throughput sequencing analysis was conducted on the library to understand the microbial diversity in the steamed buns.Through cluster analysis,the variation trends of different microbial species in fresh and wet surface storage were obtained.1.To study the bactericidal effect of ozone water on fresh and wet surface staphylococcus aureus and the inhibitory effect of natural bacteriostatic agent on fresh and wet surface staphylococcus aureus during storage.Control ozone water concentration 0?20 mg/mL,treatment temperature 20?60?,treatment time 0?20 min,analysis of different conditions of ozone water on the surface of fresh and wet surface of the bactericidal effect of staphylococcus aureus,then combined with-polylysine additive range of 0%?0.03%storage,study on the inhibitory effect of bacteriostatic agent on fresh and wet surface of staphylococcus aureus.Results:ozone water concentration of 20 mg/mL,treatment temperature of 60?,treatment time of 15 min,can produce a good bactericidal effect on staphylococcus aureus,under the condition of pretreatment can reduce the fresh wet surface of staphylococcus aureus 4.38 logCFU/g,-polylysine added to 0.03%of the best inhibition effect on staphylococcus aureus.Therefore,reducing the starting value of fresh and wet surface staphylococcus aureus and adding bacteriostatic agent in storage combined with cold chain condition can effectively control the number of staphylococcus aureus,which has certain guiding significance for the control of staphylococcus aureus in fresh and wet surface processing industry.2.To study the antibacterial effect of natural antibacterial agent on fresh and wet surface of staphylococcus aureus and its preservation effect on fresh and wet surface.The additive amount of-polylysine ranged from 0%to 0.03%.The dosage of nisin ranged from 0%to 0.025%.The addition of lactic acid ranged from 0%to 2%.The inhibitory effect of staphylococcus aureus under different conditions was analyzed,and the effect of this condition on the quality of fresh and wet surface during storage was analyzed.When the addition amount of-polylysine was 0.03%,nisin was 0.00625%and lactic acid was 2%,it had a good antibacterial effect on staphylococcus aureus.Under the condition of 2.51 log CFU/g.25?,the pretreatment can reduce the fresh wet surface of staphylococcus aureus 2.51 log CFU/g.Under the condition of 25?,the storage can extend the shelf life of fresh wet surface from 72 h to 144 h,and from 9 days to 18 days at 4?.Therefore,-polylysine,lactic acid and nisin can produce a strong bacteriostatic effect on staphylococcus aureus,reduce the starting value of fresh and wet surface microorganisms and the safety control of cold chain in storage can effectively extend the shelf life of noodles,and it has a certain application prospect in fresh and wet surface processing industry.3.According to the analysis of microbial diversity,the main bacterial species are:Cyanobacteria(Cyanobacteria),Firmicutes(F irmicutes),Proteobacteria(Proteobacteria),Actinobacteria(Actinobacteria),Chloroflexi(bacilaria),Bacteroidetes(Bacteroidetes),Acidobacteria(acidobacteriaceae),Gemmatimonadetes(bacteromonas),etc.A total of 29 types of bacteria were obtained,of which cyanobacteria accounted for 38.39%,the largest proportion,and were the dominant species in fresh and wet surface.The abundance of fresh and wet surface storage with and without antibacterial agent was significantly different.The use of antibacterial agent could inhibit the growth of some bacteria.