Tudy On Inhibitory Effect Of Microwave Treatment On Melon Caused Rot Fungi

Xinjiang is the main producing areas of melon, but loss of the melon in the process of storage, transportation and sales hold about30%. Therefore, the work of disease prevention and control after melon collection is the key to ensure the continued development of the melon industry, improve the economic efficiency of Xinjiang melon and the transformation of advantage resources of Xinjiang melon. In this study, melon was sterilized by microwave, explored the microwave impact on inhibitory effect of pathogens after the collection of melon, specific conclusions are following:1. Separated from the storage on the incidence of melon identified three main caused rot fungi:Penicillium sp.、Fusarium sp.、Alternaria sp,, were inoculated on a plate medium, respectively, Continuous and intermittent treatment by using microwave0s、10s、30s、60s、90s、120s, hot water treatment in the same temperature condition as a control group, the total number of colonies and the plaque diameter for the experimental index, studied the inhibitory effect of microwave on the melon caused rot fungi. The results showed that: Among the three methods, the batch-type microwave treatment effect is the best, the continuous microwave treatment is the next, the water bath processing is the worst, and have a significant difference among treatments (P<0.001). For the spore morphology of three caused rot fungi conducted observation under the electron microscope, the results showed that: after120s batch-type microwave treatment, the Penicillium conidia atrophy depression; Fusarium spores wilting, diaphragm disappeared; Alternaria spores atrophy, The structure of top beak-like are destroyed.2. The spore suspension of processing with different microwave time damage inoculated in melon, storage at room temperature for6d, observe lesion diameter, depth of plaque. The results showed that:the microwave treatment can significantly inhibited growth on the melon of the three kinds of bacteria, with the increase of microwave processing time, the lesion will be decreased, have a significant difference; the spores which are processed by microwave for90s cannot be breeding on the melon:the inhibitory effect by treated with microwave to the three bacteria were following:Fusarium> Penicillium> Alternaria fungus.3. The melon was microwave treated after48h of lesion inoculation with spore suspension, and storaged at room temperature for6d, and observed the lesion diameter, plaque depth, and determination of enzyme activity of the lesion surrounding tissue, and the inhibition effect of microwave on infection caused rot fungi on melon were studied. The results showed that:the microwave treatment can significantly inhibited growth on the melon of the caused rot fungi, the Lesion diameter and depth were increased with the decreased processing time (P<0.05); The microwave treatment can effectively inhibit the increased of LOX activity, and increase the activity of POD、SOD、PPO、PAL, and CAT was not affected by microwave treatment.4. With scanning electron microscopy conducted microscopic observation to the epidermis, stomata, subcutaneous tissue, the natural crack, and flesh of the melon, the results showed that:as the microwave processing time is greater than in the60s, the natural crack of epidermis in melon can be destroyed, pulp organization began a slight fold; as the microwave processing time is greater than in the90s, stomata on epidermis of melon slightly sunken; after processed120s, the subcutaneous structure will get a certain degree of damage.5. The perfect melons processed by batch-type microwave, conducted storage experiment in cold at4-6℃. Determinate of physiological and biochemical indicators per7d, the total determination time was7d, study the microwave processing to the fresh prevention effect of melon. The results showed that:as the microwave processing time was60s, can significantly reduce the permeability of cell membrane, effectively inhibit the reproduction of the caused rot fungi, in favor of maintaining melon hardness, reduce the decay rate, improved the storability and disease resistance ability in melon, maintained the nutrient content and value of the goods which are the melons should be.