Efficacy of heat and ethanol spore treatments for the isolation of psychrotrophic Clostridium spp. associated with the spoilage of chilled vacuum-packed meats

Psychrotrophic Clostridium spp. associated with chilled meat spoilage are difficult to isolate and culture. In this study the kinetics of heat and ethanol spore inactivation was determined as a first step towards optimising the recovery of psychrotrophic clostridial spores from meat and environmenta...

Full description

Saved in:
Bibliographic Details
Published in:International journal of food microbiology 1998-01, Vol.39 (1), p.61-68
Main Authors: Broda, Dorota M, De Lacy, Karen M, Bell, R.Graham
Format: Article
Language:English
Subjects:
Animals
Biological and medical sciences
Cattle
Chilled meat
Clostridium - drug effects
Clostridium - growth & development
Clostridium - isolation & purification
Ethanol - pharmacology
Food industries
Food Microbiology
Food Packaging
Fundamental and applied biological sciences. Psychology
Heat resistance
Heat sensitivity
Hot Temperature
Meat - microbiology
Meat and meat product industries
Microbial spoilage
Psychrotrophic clostridia
Sheep
Spore recovery
Spores, Bacterial - drug effects
Spores, Bacterial - growth & development
Spores, Bacterial - isolation & purification
Time Factors
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Psychrotrophic Clostridium spp. associated with chilled meat spoilage are difficult to isolate and culture. In this study the kinetics of heat and ethanol spore inactivation was determined as a first step towards optimising the recovery of psychrotrophic clostridial spores from meat and environmental samples. To determine heat inactivation, spores of nine isolates associated with spoiled chilled or frozen meat and a psychrotrophic reference strain Clostridium algidicarnis NCFB 2931, suspended in phosphate buffer, were exposed to temperatures between 75°C and 95°C for 0 to 120 min using a submerged tube procedure. Survivors after various temperature-time combinations were enumerated on Peptone Yeast Extract Glucose Starch (PYGS) agar containing lysozyme. D-values and z-values for each spore suspension were determined from their respective survival curves. To determine ethanol inactivation, similar phosphate buffer spore suspensions were mixed with equal volumes of absolute ethanol, incubated at 20°C and survivors enumerated on lysozyme-containing PYGS agar after 0 to 300 min. Based on spore heat inactivation, the 10 isolates could be grouped as having either heat-sensitive or heat-resistant spores. For heat-sensitive spore types, 60 min ethanol treatment gave maximum spore recovery whereas for heat-resistant spore types, heat treatment at 80°C for 10 min gave the best recovery. When the spore heat-resistance type is unknown, as would be the case when attempting an isolation from spoiled product, both an ethanol treatment and a separate heat treatment should be used, to ensure maximum spore recovery.
ISSN:0168-1605
1879-3460
DOI:10.1016/S0168-1605(97)00119-0