pH值、温度及预脉冲电场处理对大肠杆菌O157:H7脉冲电场及热灭活的影响

Effects of pH, temperature, and pre-pulsed electric field treatment on pulsed electric field and heat inactivation of Escherichia coli O157:H7.

作者信息

Evrendilek Gulsun Akdemir, Zhang Q Howard

机构信息

Faculty of Agriculture, Department of Food Engineering, Mustafa Kemal University, Tayfur Sokmen Campus, 31040 Alahan, Hatay, Turkey.

出版信息

J Food Prot. 2003 May;66(5):755-9. doi: 10.4315/0362-028x-66.5.755.

DOI:10.4315/0362-028x-66.5.755

PMID:12747681

Abstract

This investigation was undertaken to study the inactivation of Escherichia coli O157:H7 by pulsed electric field (PEF) treatment and heat treatment after exposure to different stresses. E. coli O157:H7 cells exposed to different pHs (3.6, 5.2, and 7.0 for 6 h). different temperatures (4, 35, and 40 degrees C for 6 h), and different pre-PEF treatments (10, 15, and 20 kV/cm) were treated with PEFs (20, 25, and 30 kV/cm) or heat (60 degrees C for 3 min). The results of these experiments demonstrated that a pH of 3.6 and temperatures of 4 and 40 degrees C caused significant decreases in the inactivation of E. coli O157:H7 by PEF treatment and heat treatment (P < 0.05). Pre-PEF treatments, pHs of 5.2 and 7.0, and a temperature of 35 degrees C, on the other hand, did not result in any resistance of E. coli O157:H7 cells to inactivation by PEF treatment and heat treatment (P > 0.05).

摘要

本研究旨在探讨不同应激条件下，脉冲电场（PEF）处理和热处理对大肠杆菌O157:H7的灭活效果。将大肠杆菌O157:H7细胞分别暴露于不同pH值（3.6、5.2和7.0，处理6小时）、不同温度（4、35和40℃，处理6小时）以及不同的预PEF处理条件（10、15和20 kV/cm）下，然后分别用PEF（20、25和30 kV/cm）或加热（60℃处理3分钟）进行处理。实验结果表明，pH值为3.6以及温度为4℃和40℃时，PEF处理和热处理对大肠杆菌O157:H7的灭活效果显著降低（P < 0.05）。另一方面，预PEF处理、pH值为5.2和7.0以及温度为35℃时，大肠杆菌O157:H7细胞对PEF处理和热处理的灭活未产生抗性（P > 0.05）。