Inhibition Kinetic Model And Mechanism Of Cinnamaldehvde Against Food-borne Pathogens

In this paper,common food-borne pathogens(Salmonella,Staphylococcus aureus and Listeria monocytogenes)as the research object,the effect of cinnamaldehyde on foodborne pathogens at 37°C.Combines four concentrations of cinnamaldehyde(0,0.1,0.5,1.0% vol/wt)and four temperatures(55,60,65 and 70°C)to research the lethal effect of three food-borne pathogens,according to the experimental results to predict the thermal inactivation curves of Salmonella in ground pork.And preliminary Study on the antibacterial mechanism of cinnamaldehyde against Salmonella,Staphylococcus aureus and Listeria monocytogenes by scanning electron microscopy.The results of this research were as follows:(1)In liquid medium,cinnamaldehyde have great influence on the growth of Salmonella,adding 0.05% and 0.1% cinnamaldehyde Salmonella difference of about 1log CFU / m L,gap is gradually narrowing after 12 h.Combines processing temperature and different concentrations,cinamaldehyde has the greast effect on the thermal inactivation of salmonella in the ground pork at 65°C,add 1.0% cinnamaldehyde reduced heat treatment time from 3 min to 1min.Compared with logistic model and linear model,the logistic model is more suitable for fitting with primary thermal inactivation regression curve of cinnamaldehyde against salmonella in ground pork,due to it has higher r value.Then,quadratic regression model has higher fitting degree,and was used as secondary model to predict the relationship of Lnt7.0,cinnamaldehyde concentration and heart treatment temperature.Scanning electron microscopy(SEM)observe the influences of salmonella cell morphology before and after cinnamaldehyde treatment,salmonella cells are disrupted,appear holes,cellular shape changes,by the stubby become elongated after cinnamaldehyde treatment.(2)At 37°C broth,the bactericidal effect of cinnamaldehyde on Staphylococcus aureus is strongest,when it reached the level of sterility testing at 12 h,significantly higher than the Salmonella and Listeria monocytogenes.Combine with different concentration of cinnamaldehyde and traditional heat treatment,1.0% cinnamaldehyde has a great impact on S.aureus resistance at 75°C,reduce the heart treatment time from 5 min to 3min.The four common models are compared,the results found that the coefficient of polynomial fitting is the highest,so was chosen as the primary model to describe the thermal inactivation curve of Staphylococcus aureus in ground pork after cinnamaldehyde treatment,secondary model selection principle based on primary model,fitting the relationship of Ln t7.0,cinnamaldehyde concentration and heat treatment temperature,fitting results showed linear model is more suitable to describe the relationship of Lnt7.0,cinnamaldehyde concentration,heat treatment temperatures.SEM: cinnamaldehyde make Staphylococcus aureus bacterial cells are disrupted,the cells appear holes,intracellular fluid leakage,cell shapes and sizes are different.With the increasing concentration of cinnamaldehyde,the damage also will be deepen.(3)With increasing concentration,the inhibitory effect of cinnamaldehyde on Listeria monocytogenes did not increase,only adding o.o5% cinnamaldehyde to make the colonies value of Listeria monocytogenes reduced about 6 log CFU /ml.The thermal inactivation impact of cinnamaldehyde against Listeria monocytogenes is the most obvious at 70°C,hearting time of added 1.0% cinnamaldehyde sample is shortened,reduced from 3min to 0.4min.At different treatment temperature,the inhibitory effect of cinnamaldehyde on Listeria monocytogenes were fitted,according to the goodness of fit,choose a more appropriate model in four primary polynomial model as primary model,the results showed that the polynomial fitting is the most appropriate.The relationship of Lnt7.0,treatment temperature and cinnamaldehyde concentrations are fitted,the coefficients of quadratic regression model is the highest,and so choose polynomial fit as primary model to describe the thermal inactivation curve of Listeria monocytogenes in ground pork after cinnamaldehyde treatment,and selected quadratic regression model to describe the relationship of Lnt7.0,treatment temperature and cinnamaldehyde concentrations as secondary model.By scanning electron microscopy: Listeria monocytogenes after cinnamaldehyde treatment,cell color dull,cells were curled and variable length.