Behavior of Escherichia coli O157:H7 and Listeria monocytogenes in Tryptic soy broth subjected to various low temperature treatments
Resource
Food Research International, 32(1), 1-6
Journal
Food Research International
Pages
1
Date Issued
1999
Date
1999
Author(s)
Chou, Cheng-Chun
Cheng, Shu-Jen
Wang, Yu-Chi
Chung, King-Thom
Abstract
The inactivation and injury of Escherichia coli O157:H7 and Listeria monocytogenes in Tryptic soy broth stored at -5, -18 and -28°C were studied. Regardless of storage temperature, viable populations of E. coli O157:H7 and L. monocytogenes determined with TSA (uninjured and injured cells) or TSAB (uninjured cells), decreased as the storage time increased. However, the least surviving population of both test organisms was noted when stored at -18°C followed by those stored at -28 and -5°C. The viable populations of E. coli O157:H7 determined either with TSA or TSAB, was reduced most drastically during the first day of storage then decreased slowly thereafter. Viable populations of L. monocytogenes declined slightly and gradually during the entire storage period. Furthermore, E. coli O157:H7 was found more susceptible to the freezing storage than L. monocytogenes. After 21-day storage at -18°C, population reduction of E. coli O157:H7 determined with TSA was ca 1.72 log CFU/ml. On the other hand, a population reduction of only 0.64 log CFU/ml was noted with L. monocytogenes. Besides, the surviving population of E. coli O157:H7 contained a larger proportion of injured cells than L. monocytogenes.
Type
journal article
File(s)![Thumbnail Image]()
Loading...
Name
82.pdf
Size
24.16 KB
Format
Adobe PDF
Checksum
(MD5):276f0f3fa41e0db70156de9d831074f6