Study On Cherry Tomato And Red Bayberry Postharvest Storage And Antibacterial Cleaning Methods For Fruit Minimally Processing

Microprocessed fruits,also called fresh-cut fruits,semi-processed fruits and instant fruits.Microprocessed fruits are processed fruits made from fresh fruits that have been cleaned,peeled,trimmed,shredded,packaged,and stored.In this study,cherry tomatoes and red bayberry are widely used in China’s micro-processing fruit industry,were selected as the research objects.Both fruits are small fruits,and their micro-processing mainly involves cleaning and packaging,and does not involve peeling,dressing,cutting,and so on.To study the antibacterial cleaning methods of cherry tomatoes and red bayberry,it is of great significance to understand the freshness preservation in the micro-processing process.In order to simulate the dynamics of microbial proliferation and attenuation in two kinds of fruits during short-term storage,the Escherichia coli dynamic under the room temperature(22℃)and low-temperature(4℃)storage in cherry tomato and red bayberry were established respectively.The results showed that the Escherichia coli proliferation and attenuation in cherry tomato and red bayberry were fitted well with the 4 kinds of primary prediction models.After logarithmic transformation,the correlation coefficient of the growth and attenuation dynamic curves are 0.98-0.99 for cherry tomato,the correlation coefficient between growth and attenuation dynamic curves is 0.91-0.94 for red bayberry,and the sum of square residual is low.The results have important guiding significance.The effect of different cleaning methods on the removal of microorganisms in cherry tomatoes and red bayberry was compared.Routine test were conducted on the aerobic bacteria,Escherichia coli,mold,yeast and Salmonella Typhimurium,which are common food-safety-related microorganisms.The results showed that various sanitizing methods can reduce the microorganism in cherry tomato,but the reduction ability is different from method to method.The sanitizing method with better elimination effect on aerobic bacteria in cherry tomato is 0.1%acidified sodium chlorite,2%lactic acid and 2%malic acid.The better sanitizing methods to Escherichia coli O157:H7 were 0.02%chlorite,0.1%sodium chlorite and 0.1%acidified sodium chlorite respectively.For yeast in cherry tomato.the better sanitizing methods is 0.1%acidified sodium chlorite and 2%lactic acid.The sanitizing methods used in this experiment can significantly reduce Salmonella Typhimurium in cherry tomato.Among them,2%citric acid,2%lactic acid and 0.1%acidified sodium chlorite showed the optimum effect.The three sanitizing methods completely removed inoculated Salmonella Typhimurium from the surface of cherry tomato.Compared to cherry tomato,the reduction values of eight sanitizing methods on microbial contamination of red bayberry was relatively poor.The results indicated that 2%lactic acid had significant reducing effect on all microorganisms except mold in red bayberry.The anitizing method of 0.1%acidified sodium chlorite was second,but it has a significant effect on mold remove in red bayberry.Other sanitizing methods were not effectively reduced the mold and yeast in red bayberry.The experiment confirmed that the best cleaning method for cherry tomatoes and red bayberry was 0.1%ASC(pH=2.30)treatment for two minutes.On this basis,the study randomly selected a large number of commercial samples to verify the effectiveness and applicability of the best cleaning method.It was found that during the verification of the optimal cleaning method for 50 commercially available cherry tomatoes samples,the antibacterial cleaning method 0.1%ASC used in this study had a significant effect on the removeal of all kinds of common microorganisms in cherry tomatoes.According to the analysis of food hygiene limit standard,two-minute treatment of 0.1%ASC has obvious antibacterial effect on cherry tomatoes,which can be used as a practical candidate antibacterial cleaning method.For red bayberry,two minutes of treatment with 0.1%ASC has certain scavenging effect on all kinds of microorganisms expect Escherichia coli.This method can not be used as the most effective antibacterial cleaning method in the mocroprocessing of red bayberry,and further optimization is needed.