Establishment of practical instrument for microbial inactivation and food processing by using microbubbles of supercritical carbon dioxide

l)微生物灭活和酶灭活评价研究了溶解二氧化碳浓度（dCO_2）和处理温度对酿酒酵母灭活的影响。结果表明，失活行为符合一级反应，且处理温度和dCO_2浓度相当。研究了处理温度和dCO_2浓度对黑曲霉孢子死亡动力学的影响。死亡动力学遵循一级反应。处理温度和dCO_2浓度相当。但温度与浓度之间存在交互作用关系。2)酶失活动力学研究了微泡SC-CO_2处理后肌红蛋白、卵白蛋白、牛血清白蛋白和β-乳球蛋白的构象变化。研究了pH对微泡SC-CO_2处理酸性蛋白酶、碱性蛋白酶、碱性蛋白酶、木瓜蛋白酶和葡萄糖淀粉酶失活的影响。d值(5。α-淀粉酶在35℃、30 MPa条件下的时效值（0 min）小于70℃条件下热处理的时效值（227 min）。酸性蛋白酶在50℃、30 MPa条件下的d值为15。4 min， 50℃热处理后为233 min。为研究CO_2释放对橙汁风味保留的影响，采用SC-CO_2微泡连续处理单一强度橙汁。因此，开发了一种新的co2释放技术。4)蛋白质构象和功能的改变由于微泡SC-CO_2处理是一种有效的蛋白质构象改变技术，因此将其用于分解牛奶中的过敏原。然而，由于严重的凝胶化，目前的仪器无法使用。5)实用仪器和操作条件的建立与岛津株式会社、北海制罐株式会社合作，对微泡SC-CO_2处理仪器进行了规模化生产。目前已建成中型仪器（处理能力250kg/h），可再现小型仪器的结果。少

l) Evaluation of microbial inactivation and enzyme-inactivationEffects of the concentration of dissolved carbon dioxide (dCO_2) and treatment temperature on inactivation of Saccharomyces cerevisiae were investigated. It was shown that the inactivation behavior followed to a first-order reaction, and the treatment temperature and dCO_2 concentration were equivalent for the inactivation. Death kinetics of the spores of Aspergillus niger were investigated on the treatment temperature and the concentration of dCO_2. The death kinetics followed to a first-order reaction. The treatment temperature and the concentration of dCO_2 were equivalent for the inactivation. However, the interactive relation between the temperature and concentration was observed.2) Kinetics of enzyme inactivationThe conformational changes of myoglobin, ovoalbumin, bovine serum albumin and β-lactoglobulin by microbubbles SC-CO_2 treatments were investigated. The effect of pH on the inactivation of acid protease, alkali … More protease, papain and glucoamylase by microbubbles SC-CO_2 treatments was made cleared. The D-value (5. 0 min) of α-amylase at 35℃ and 30 MPa was small than the value (227 min) by thermal treatment at 70℃. The D-value of acid protease at 50℃ and 30 MPa was 15. 4 min, on the other hand, the value was 233 min by thermal treatment at 50℃.3) Quality of the food product processed by present techniqueTo investigate the effect of CO_2 release on the flavor retention of orange juice, single strength orange juice was subjected to continuous treatment with micro-bubbles of SC-CO_2. As a result, a novel technique for CO_2 release was developed.4) Changes in the conformation and function of proteinBecause a microbubbles SC-CO_2 treatment is a useful technique for conformational changes of proteins, it was applied to decompose allergens in cow milk. Present instrument, however, was not able to use, because of severe gelation.5) Establishment of practical instrument and operational conditionWe tie up with Shimadzu Co., LTD and Hokkai Can Co., LTD to scale up the instrument for microbubbles SC-CO_2 treatment. At present, medium scaled instrument (treatment capacity ; 250kg/h) was constructed and the instrument could reproduce the results obtained by a small instrument. Less