Application Of Ultra-High-Pressure In Apple Juice Processing

Fresh juice is highly welcomed by consumers, which contains the aroma components and nutrient substance and Traditional sterilization method of fruit juice is thermal sterilization, sterilizing effect is excellent, now this kind of sterilization method is still used. But thermal sterilization would damage the nutrition, reduce the fruit juice quality and nutritional value, and greater energy consumption. So looking for an alternative to thermal sterilization becomes the food industry’s research focus. Ultra high pressure (UHP) technology is considered to be one of the most potential and promising to thermal treatment techniques in food industry.The research studied the clarified apple juice death law of microorganism with different pressure. Compared sterilization effects of ultra high pressure and thermal sterilization to clarified apple juice. Sensory quality, nutrient components and physical and chemical properties of clarified apple juice were studied as well based on achievement of sterilization requirements. And optimized ultra high pressure sterilization condition of clarified apple juice and studied flavor and storage period of clarified apple juice after ultra high pressure treatment.Studied the death law of microorganism in clarified apple juice with different pressure. The results showed that death characteristic curve of total bacteria were fitted by exponential model, the higher the pressure, the faster the rate of decline. And concluded the pressure resistance parameters of total bacteria:Dp and Zp.Took light transmittance, pH value, soluble solid content, turbidity, titratable acidity, color value, off color, reducing sugar, vitamin C, amino nitrogen as indexes, Researched sterilization effect and quality of clarified apple juice which dealed with different pressure and time, The results showed that the optimum ultra high pressure condition was 300 MPa and 16 min, clarify apple juice dealed with this condition not only met the sterilization requirements, but relative quality was also best.Compared the two sterilization ways, considering color value, off color, reducing sugar, vitamin C, amino nitrogen as indexes, the result showed that after ultra-high pressure sterilization clarify apple juice each index was closer to the original fruit juice. It was concluded that UHP treatment could effectively inactivate the microbe and maintain the aroma and quality of clarified apple juice.Took the color of clarified apple juice as a quality factor, researched the quality change regularity of clarified apple juice with processing at 300 MPa and 16 min in the process of storage. The results showed that, the color of clarified apple juice dealed with ultra-high pressure was index change rule with the storage time is extended. Prediction model of shelf-life was established in storage experiment:lgθ=3.2079-0.0334 C.