Combined effect of sodium chloride, pH and storage temperature on growth and toxin production by clostridium botulinum
Combined effect of sodium chloride, pH and storage temperature on growth and toxin production by clostridium botulinum
Date
2007
Authors
Lalitha, K.V.
Gopakumar, K.
Journal Title
Journal ISSN
Volume Title
Publisher
Taylor & Francis Group Ltd
Abstract
The effect of sodium chloride concentration (3, 4, 5, 6, 8, 10 and 12%) and storage temperatures (4C, 10C, 15C and 30C) on toxin production by Clostridium botulinum isolated from tropical fish was studied in anaerobic cooked meat medium. The combined effect of sodium chloride (3, 5%), low pH (5.5) and low temperature (15C) on toxin production by C. botulinum was also examined. The toxicity was tested by mouse bioassay. An increase in lag phase was noticed by increasing the salt concentration. At 30C, spores of C. botulinum type E were able to grow and produce toxin up to 3% salt (aw = 0.976), whereas for types C and D the limiting salt concentration was 4-5% (aw = 0.97-0.974) and for types A and B it was 8% (aw = 0.952). By lowering the storage temperature, an increase in lag phase and time to toxicity was noticed for type E at 3% salt and for types A, C and D at 5% salt level. The probability of growth and toxin production at 5% salt decreased as the pH and storage temperature (combined stress) was decreased.
Description
Keywords
Clostridium botulinum, toxin production, sodium chloride, pH
Citation
Journal of Aquatic Food Product Technology 2007: 16(2), 27-39