Ultrasound,Heat And Nisin Coordination Treatment Effect On Bacillus Subtilis Spores Inactivated And Its Application In Fruit And Vegetable Juice Sterilization

Certain Bacteria spore is dormant,due to the special structure of the spore has the very strong antiseptic resistance,routine sterilization method is hard to inactivation it.High temperature thermal sterilization the commonly used method is to inactivation spores in food,can significantly extend the shelf life of food.Ultrasonic technology is a kind of thermal sterilization means,in ensuring food security has a broad development prospects.Sound hot composite technology(Thermosonication,TS)as a new type of food sterilization technology,is becoming a hot spot of research in recent years,a significant sterilization effect.In order to further reduce the use of high temperature in hot composite technology,this study focuses on strengthening sterilization effect and chemical auxiliary TS application in fruit and vegetable juice sterilization.The researchers for ultrasonic,there is no heat and Nisin coordination treatment to study the effect of inactivationing Bacillus subtilis spores.In this paper,the main research contents and results were as follows:(1)Ultrasonic,heat and Nisin coordination treatment effect of inactivationing Bacillus subtilis sporesThis chapter studies the processing time for 30 min,Nisin(0.2%,0.4%)auxiliary different ultrasonic power(300 W,600 W)and temperature(60℃,75℃ and 90℃),analysis of different treatment survival logarithm,spore Bacillus subtilis spores OD600,260,280.values and leakage in the DPA.Studies have shown that Nisin synergy TS processing can further strengthen the spore inactivationing effect,show that TS and Nisin on inactivation of spore has a synergistic effect,the release of the spore content,uv material leakage,the DPA to release a quantity to have increased significantly.(2)Ultrasonic,heat and Nisin coordination treatment effect on Bacillus subtilis spores morphological structureThis chapter to compare the influence of different processing of spore morphology,by flow cytometry instrument testing analysis,laser granulometer and scanning electron microscopy(sem).Temperature ultrasonic treatment on spore membrane permeability is affected,the smaller particle size change,spore morphology complete;Nisin synergy TS processing,spore lining damage is bigger,membrane permeability increased,spore size,spore structure destruction makes key material leaked,spore basic physiological and metabolic disorders.(3)Ultrasonic,heat and Nisin coordination treatment effects on Bacillus subtilis spores in the key materialThis chapter studies the different processing on the spore Na+/K+atpase activity.After Nisin synergy TS treatment,Na+/K+atpase activity decreased significantly.For the analysis to explore the different treatment of spore membrane lipid,protein,nucleic acid,the influence of key material such as Fourier infrared spectrometer is used to analysis.Analysis found that phase change spore membrane phospholipids,spore protein secondary structure was destroyed,spore degeneration in nucleic acid substances,peptidoglycan layer structure change.(4)The ultrasonic synergy heat and Nisin sterilization dynamics research and application of Bacillus subtilis sporesThis chapter,the research of the Bacillus subtilis spores under the different processing time dynamics and its application in food disinfection sterilization,the spore inactivation and spore suspension OD260,OD280,OD600 and value correlation analysis.By comparing the fitting degree between the model parameters,to find the most suitable for Logistic model fitting spore kinetics curve.Amount of spore inactivation and OD260,OD280 and OD600 values were extremely significant correlation.At the same time in fruit and vegetable juice system is studied in different treatment effect of inactivationing Bacillus subtilis spores,Browning degree,the influence of pH and total solids.Studies have found that Nisin synergy TS processing in fruit and vegetable juice system have significant inactivationing effect on Bacillus subtilis spores,fruit and vegetable juice pH value increases,the total solids did not change significantly,at the same time during storage,Nisin synergy TS processing can effectively reduce the browning rate of the apple juice and carrot juice.In this paper,ultrasonic,heat and Nisin coordination treatment effect of inactivationing Bacillus subtilis spores and its application in fruit and vegetable juice of sterilization were studied.Nisin synergy TS processing can be further reduced in the process of sterilization temperature,the better effect of sterilization,get better quality of food,can also handle the application in food disinfection for Nisin synergy TS to provide the reference.