Inhibition And Mechanism Of Three Plant-Derived Active Substances On Alicyclobacillus Spp. In Fruit Juice

Alicyclobacillus spp.is are common spoilage bacteria in fruit juice.Because of their acidophilic heat resistance,it is difficult to kill them by traditional methods.Therefore,the plant-derived bacteriostatic agent for finding the bacteria is one of the methods for controlling the bacteria.Plant-derived active substances have attracted the attention of food companies and consumers because of their safety,oxidation and bacteriostatic properties,providing a material method for the effective control of microorganisms in the food industry.Therefore,in this study,the three plant-derived active substances such as chlorophyll acid,cinnamic acid and thymol were used as the basic materials to explore its inhibitory effect on Alicyclobacillus spp.and its mechanism,and further alicyclic phenol as carrier Evaluation of the antibacterial effect of Bacillus licheniformis and spores.The main conclusions are as follows:(1)The experiment showed that chlorogenic acid had inhibitory effect on Alicyclobacillus spp.and the diameter of the inhibition zone was 14.50 ± 0.5 mm.The measured MIC value was 2 mg/m L,and the MBC value was 4 mg/m L.Chlorogenic acid caused the cells to shrink and shrink,and the morphology was severely damaged.The amount of nucleic acid and protein leakage increased with the increase of chlorogenic acid time and concentration.The results of SDS-PAGE showed that after chlorogenic acid The color of the intracellular protein electrophoresis bands of the cells was significantly lighter,and some of the individual electrophoresis bands even disappeared.With the increase of the concentration of chlorogenic acid,the changes of the protein electrophoresis bands were more obvious.(2)Experiments showed that cinnamic acid inhibited Alicyclobacillus spp.and the diameter of the inhibition zone was 20.40 ± 0.4 mm.The measured MIC value was 0.375mg/m L,and the MBC value was 0.5 mg/m L.Under the electron microscope,cinnamic acid was observed to cause pores in the cells.High concentration of cinnamic acid could damage the morphology of the cells.The amount of nucleic acid and protein leaked increased with the increase of cinnamic acid treatment time and concentration.SDS-PAGE electrophoresis The results showed that the intracellular protein electrophoresis bands of the cells were significantly lighter at the MBC level after cinnamic acid treatment,and some bands even disappeared.(3)Experiments showed that thymol inhibited the bacteria and spores.The diameters of the inhibition zone were 2.55±0.05 mm and 12.30 ± 0.07 mm,respectively;the MIC values were 0.25 mg/m L and 0.5 mg/,respectively.The m L and MBC were 0.25 and greater than 1mg/m L,respectively.Sweeping electron microscopy showed that thymol could damage the cell membrane of the Alicyclobacillus spp.and spores,and the degree of damage was related to the concentration;the leakage protein and nucleic acid bacteria of the Alicyclobacillus spp.and spores increased with the increase of the concentration;SDS-PAGE The results of electrophoresis showed that thymol could change the protein content and content of the Alicyclobacillus spp.and spores,and the types and molecular weight distribution of the proteins in the spores were higher than those of the Alicyclobacillus spp.;the number of colonies within 24 hours of normal growth of the cells and spores was determined.It can be seen that thymol can inhibit the growth of bacteria,reduce its ability to form spores,and inhibit the germination of the spores.The inhibition ability is proportional to the concentration of thymol;the detection of different concentrations of thyme on the cells The effect of the amount of lignans found that thymol at a concentration equal to or greater than MIC inhibited the production of guaiacol.