They Did Back Then
* Master of Science
completed 2004, University of Guelph
Advisor: Professor Y. Kakuda
Professor Richard D. Moccia
compounds for antibacterial activity against spoilage
bacteria inoculated on rainbow trout tissue.
screening procedure using sterile chunks of rainbow trout
(Oncorhynchus mykiss) as the growth medium was to evaluate
compounds for their efficacy in controlling the growth of
two fish spoilage bacteria. Pseudomonas putida
and Shewanella putrefaciens. The fish
chunks (4 cm2) were inoculated with spoilage bacteria and
then dipped into various treatment solutions for 30
seconds. After incubating at room temperature for 24
hours, bacterial counts were taken and log reduction ratio
values (LR) calculated. In this study, all test
compounds were considered effective inhibitors if their
log reduction values minus one standard deviation (LR-ISD)
was equal to or greater than 3.0. Acetic acid,
propionic acid, formic acid, valeric acid, allyl
isothiocyanate (AIT), hexadecytrimethylammonium bromide
(HTAB), ethanol, clove oil, lemongrass oil, peppermint
oil, cinnamon oil and 24 hours of exposure to acid water
all produced LRs of 3 logs or greater against, P.
putida S. putrefaciens was
found to be more sensitive to treatments than P.
putida. All substances that were classified
as inhibitors caused potentially detrimental sensory
changes to the trout meat.