Study On The Occurrence Regularity And Regulation Technology Of Mildew Disease In Apple Shelf After Storage

In order to reduce the adverse effects of apple mildew on consumers and the market,it is of great practical significance and guiding significance to explore an excellent preservation measure and prevent mildew disease in the field of apple preservation.In this paper,Fuji apples were used as test materials,mainly in the following four aspects: isolation and purification of pathogenic bacteria causing mildew disease,and determination of its causativeness;inhibition of clove essential oil and 1-MCP on Fuji apple mildew pathogens;1-MCP on the control and quality of Fuji apple heart disease after storage;the effect of double treatment of 1-MCP before storage on the control and quality of Fuji apple heart disease.The main methods are concluded as follows:1.Experimental method: In the antibacterial experiment,the pathogenic bacteria(Alternaria and Penicillium)were isolated and purified from the fruit of the heart disease,and then the in vitro antibacterial test of different concentrations of clove oil and 1-MCP was performed.In the in vivo test,200 μL of isolated and purified apple pathogens(107 CFU/m L)were inoculated into the fruit heart,and then the vitro bacteriostatic test of different concentrations of clove oil and 1-MCP was carried out;In the MCP control disease experiment,the post-harvest apples were stored in the precision temperature control library at(-0.5±0.3)°C for 6 months,and then treated with 3μL/L and 5μL/L of different concentrations of 1-MCP.The decay rate,defense enzyme activity,nutritional quality and hardness,physiological indexes,volatile components and electronic nose of Fuji apple were measured at 7 days.In the 1-MCP double treatment and control experiment,1 μL/L 1-MCP treatment was carried out on post-harvest Fuji apples,and then treated with different concentrations of1-MCP.The measurement indexes and methods were the same.The effect of 1-MCP before and after storage on the quality of Fuji apples.2.Through the in vitro experiment,the minimum inhibitory concentrations of clove oil and 1-MCP against Alternaria and Penicillium were 5μL/L and 7μL/L,8μL/L and 9μL/L,respectively.In the in vivo test,the higher the concentration,the better the bacteriostatic effect for clove oil,and the optimal inhibitory concentration for Alternaria and Penicillium is 12μL/L,while for 1-MCP,it is within a certain concentration range.Within,the higher the concentration,the better the antibacterial effect,and above this optimum concentration,the antibacterial effect will decrease,and the optimal inhibitory concentration for Alternaria is 5μL/L,while the optimal inhibitory concentration for Penicillium is 7 μL/L.Combined with in vitro and in vivo tests,the minimum inhibitory concentration screened in vitro was applied to the in vivo test,and the bacteriostatic effect was poor.3.In the 1-MCP experiment after storage,from the aspect of decay rate,when the shelf is28 d,the apple rot rates of CK group,CK+ZH3.0 and CK+ZH5.0 treatment groups were47.57%,22.33% and 16.5%,respectively.Therefore,1-MCP can effectively reduce the decay rate of Fuji apples.For different concentrations of 1-MCP treatment,CK+ZH5.0treatment can significantly reduce the decay rate of apples.1-MCP can also increase the activity of POD,PPO,PAL,etc.,and the experimental results are the same as above.Treatment with 5 μL/L of1-MCP at different concentrations improved the activity of PPO and PAL,and 3 μL/L had a better maintenance effect on POD activity.From the perspective of nutritional and physiological indicators,the research results are the same.For volatile components,2-hexenal,hexanal,1-hexanol,2-methyl-1-butanol,butyl 2-methylbutyrate and hexyl acetate were Fuji apples in this experiment.The main aroma components,as well as experimental studies,found that 1-MCP has a certain inhibitory effect on these aroma components.4.1-MCP double treatment experiment results show that compared with CK group,1 μL/ L 1-MCP fumigation treatment of Fuji apple before storage can better ensure fruit quality,and the effect of 1-MCP double treatment Better.From the aspect of decay rate,when the shelf is 28 d,The apple rot rates of CK group,pre-storage 1-MCP treatment group,1-MCP+ZH3.0and 1-MCP+ZH5.0 treatment groups were 47.57%,8.74%,7.77% and 2.91%,respectively;Therefore,1-MCP can effectively reduce the decay rate of Fuji apples.For different concentrations of 1-MCP treatment,1-MCP+ZH5.0 treatment in dual treatment can significantly reduce the decay rate of apples.1-MCP can also increase the activity of peroxidase(POD),polyphenol oxidase(PPO),and Phenylalanine ammonia lyase(PAL).Among them,5 μL/L treatment in 1-MCP double treatment can better enhance the activity of PPO and PAL,while 1-MCP+ZH3.0 can better maintain POD activity.From the nutritional and physiological indicators,the treatment of 1-MCP+ZH5.0 has a better effect on the titratable acid content and hardness of the fruit,while inhibiting the respiratory intensity and ethylene production rate,and effectively ensuring the sensory quality.For volatile components,2-hexenal,hexanal,1-hexanol,2-methyl-1-butanol,ethyl butyrate and hexyl acetate were the main aroma components of Fuji apples in this experiment.According to experimental research,1-MCP has a certain inhibitory effect on these aroma components...