胡萝卜汁中大肠杆菌脉冲式超高压杀菌动力学研究  

Pulse Mode High-pressure Destruction Kinetics of E. coli in Carrot Juice

作　　者：胡菲菲[1] 朱瑞[1] 杨楠[1] 于勇[1] 和劲松[1] 朱松明[1] 

机构地区：[1]浙江大学生物系统工程与食品科学学院,杭州310058

出　　处：《农业机械学报》2014年第1期178-183,190,共7页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家高技术研究发展计划(863计划)资助项目(2011AA100800);浙江省自然科学基金重点项目(Z3090301)

摘　　要：以鲜榨胡萝卜汁为原料，利用脑心浸液琼脂和紫红胆盐琼脂两种培养基，分别研究了脉冲式超高压（300—600MPa，1～4个脉冲）对大肠杆菌的致死和致伤效应，并获得了脉冲式超高压对大肠杆菌的杀菌动力学特性。研究结果表明，随着处理压力的升高和脉冲数的增加，大肠杆菌的致伤和致死效果均显著增强。且当压力在400MPa以上时，增加脉冲次数的杀菌效果更为明显。500MPa处理2个脉冲和600MPa处理1个脉冲即可将胡萝b汁中7．8个数量级浓度的大肠杆菌全部致死。此外，脉冲式超高压处理对胡萝b汁中大肠杆菌的致伤和致死效果均符合一级动力学。通过建模分析表明，对致死效果而言，300、350和400MPa下每3．95、1．76和0．83个脉冲可使大肠杆菌的检出量下降一个数量级，而要达到相同致死效果，并使脉冲数下降一个数量级所需要提高的压力为229MPa；对致伤效果而言，300、350和400MPa下每1．68、1．26和0．48个脉冲可使大肠杆菌的检出量下降一个数量级，而要达到相同致伤效果，并使脉冲数下降一个数量级所需要提高的压力为206MPa。The effect of pulse mode high-pressure on E. coli in fresh carrot juice was studied. Destruction kinetics of E. coli was investigated after pulse mode high-pressure treatment （300 - 600 MPa, 1 4 pulses）. Enumeration was carried out in brain-heart infusion agar and violet-red bile agar to differentiate between surviving cells with and without injury. Results showed that with an increase in either pressure or pulse, both injured and killed ceils increase significantly. At more than 400 MPa, the increase of pulse, rather than pressure, makes the sterilization effect better. Two pressure pulses at 500 MPa or a pressure pulse at 600 MPa destroys the entire population （107s cfu/mL） of E. coli in carrot juice. And on both BHIA and VRBA, pulse mode high-pressure destruction of E. coli in carrot juice follows first-order kinetics under experimental conditions. Modeling analysis showed that, for lethal effect, every 3.95, 1.76 and 0. 83 pulses result in a decimal change of E. coli for 300, 350 and 400 MPa, respectively; for injured effect, every 1.68, 1.26 and 0.48 pulses result in a decimal change of E. coli for 300, 350 and 400 MPa, respectively. To achieve a same sterilization effect, when the pressure pulse decreases an order of magnitude the pressure has to increase by 229 MPa and 206 MPa, for BHIA and VRBA, respectively.

关 键 词：胡萝卜汁 大肠杆菌 超高压 脉冲 动力学 

分 类 号：TS201.3[轻工技术与工程—食品科学]