| This paper was a part of the item - "The Study on Key Technologies of High-Quality Fresh Apple Juice and Concentrated Cloudy Apple Juice" in the Tenth-Five-Year Science and Technology Plan of China.The non-thermal technology was the pivotal problem, which restricted the producing, and marketing of fresh apple juice in China. Up to now, there was no effective and practical method to resolve the processing problems. This study focused on the several prospective non-thermal inactivation technologies to keep the natural flavor and nutritional qualities of the apple juice. The presence of an inactivation processing unit operation aiming at microbial destruction was of primary importance to ascertain safety and stability of food. After the isolation and identification of the primary pathogenic and septic bacteria in the raw apple, the bactericidal effects of chlorine dioxide (ClO2) solution treatments on the microbia potted on pulp surface of apples were investigated to explore the inactivation rule. From the point of view of practicality and high efficiency, the effect of main parameters on the inactivation or sterilization efficiency of the selected pulsed magnetic field and membrane filtration technology were explored to suppress microbial growth, and reduce or eliminate the microbial load. In this part, the damages inflicted on the membrane and DNA of Escherichia coli cells treated by pulsed magnetic field was investigated to reveal the mechanism of the inaction. The flux behavior and mechanism of ceramic membranes was examined during cross-flow ultrafiltration (UF) of depectinized fresh apple juice to evaluate the effects of transmembrane pressure (TMP) and temperature on membrane fouling. On the basis of data and rules induced from the experiments, the scheme to produce fresh apple juice was brought forward and the pilot scale equipment for non-thermal inactivation was designed. By the theory of predictive microbiology technology, predictive models for the lag phase and the maximum specific growth rate of a specific spoilage organism in fresh apple juice was developed and the logistic model to evaluate the growth/no growth boundary for the pathogenic bacteria in relation to the considered independent variables was also established. From the studies above, the conclusions were:1. The raw material apple was the main resource of the pathogenic and septic bacteria of the fresh apple juice. To sanitize the microbia on the apple surface effectively, the clones of bacteria and yeasts were isolated and identified respectively by their clone physiological characteristics and the API system. The microbial load in the raw apples was between 105 and 107 cfu/g. The pathogenic bacteria such as Listeria monocytogenes and E.coli O157:H7 were found in the raw apple. The primary kinds of septic microbia were yeast, lactic bacteria, and spores.2. Production of safe fresh apple juice includes scrutinizing raw materials and reducing or eliminating the microbial load by chlorine dioxide (ClO2) solution. The inactivation rule of chlorine dioxide (C1O2) treatments on the microbiology was investigated in the process ofapple rinsing. The Central Composite Design model was used to describe the influence of main, quadratic, and cross-product effects of the environmental factors such as concentration of chlorine dioxide (C1O2), temperature, treating time and pH on the response of inactivation efficiency (log (NO/N)).3. The major factors on the inactivation efficiency of the pulsed magnetic field were strength, the number of pulses, temperature and pH of the medium. The pH of the medium effected the inactivation markedly. In low pH (<4.5), the efficiency of inactivation was higher for the treatment of Escherichia coli, Salmonella enterica and Sarcina aurea Henrici. The increase in the strength and the number of the pulses increased the efficiency of inactivation. The inactivation efficiency of pulsed magnetic field was not consistent to all kinds of microbiology. In the investigated microbiologies t...
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