热压协同下传压介质和热损失对细菌芽孢灭活的影响

Effects of Pressure Transmitting Fluids and Heat Loss on Inactivation of Bacterial Spores by Pressure-thermal Processing

以枯草芽孢杆菌和凝结芽孢杆菌为对象菌,研究热压协同处理下传压介质和热损失对其灭活效果的影响。结果表明,当温度为60℃和80℃,传压介质为橄榄油和癸二酸二辛酯,压力300-600MPa时,这2种传压介质对枯草芽孢杆菌芽孢的灭活效果相差不大,橄榄油稍高于癸二酸二辛酯的效果;而同水为传压介质时的情况相比,它们的灭活效果显著提高(P<0.05),凝结芽孢杆菌芽孢有类似的结果;而在初始温度为80℃,压力为400MPa和600MPa时,使用聚四氟乙烯套筒和不锈钢套筒模拟不同的热损失时,前者比后者更能提高对枯草芽孢杆菌芽孢和凝结芽孢杆菌芽孢的灭活效果,而且随着保压时间的延长这种效果越明显。

Effects of pressure transmitting fluids and heat loss on the inactivation of Bacillus subtilis spores and Bacillus coagulans spores by pressure-thermal processing were investigated. The results showed that the inactivation effect of Bacillus subtilis spores was close to that of Bacillus coagulans spores at 80℃ and 300-600 MPa while di-2-octyl sebacate and olive oil as pressure transmitting fluids. However, inactivation rate had significantly （P 〈 0.05） decreased while water as pressure transmitting fluids. Teflon liner had better effect on inactivation rate of Bacillus subti- lis spores and Bacillus coagulans spores than stainless steel liner and the effect increased with the increasing pressure holding time when simulating different heat loss at 80℃ and 400 and 600 MPa.