Effect of storage temperatures on the microbiological quality, safety, and viability of quahog clams, Mercenaria mercenaria

• Main Author: Brenton, Carolyn E.
• Other Authors: Food Science and Technology
• Format: Others
• Language: en
• Published: Virginia Tech 2014
• Subjects: Vibrio parahaemolyticus; Vibrio vulnificus; clam mortality; LD5655.V855 1996.B746
• Online Access: http://hdl.handle.net/10919/43131; http://scholar.lib.vt.edu/theses/available/etd-06112009-063149/

The objective of this project was to examine the effects of various storage temperatures and times on the microbiological quality, safety, and viability of hard shelled quahog clams. Samples were stored at four different incubation temperatures (3.3, 7.2, 10.0, and 12.S0C) for a period of three weeks, following their harvest from growing waters during the summer when the water temperatures were ~ SO°F, and during the winter when water temperatures were ~ 40°F. With regards to safety, clams were analyzed for two naturally-occurring pathogens, Vihrio parahaemolyticus and Vihrio vulnificus. Aerobic plate counts (APCs), coliforms, and fecal coliforms were determined to define the level of quality. During the summer, mesophilic APCs containing 2% NaCI ranged from 104 to 108 CFU/g, and during the winter, mesophilic APCs with salt ranged from < 100 ESPC to 104 CFU/g. Comparatively, during the summer, mesophilic APCs containing no added NaCI ranged from < 100 ESPC to 105 CFU/g, and during the winter, APCs without salt ranged from < 100 ESPC to 102 CFU/g. Coliform and fecal coliform counts ranged from < 0.3 to 61.1 MPN/g and < 0.3 to 24.4 MPN/g, respectively. During the summer, V. parahaemolyticus was isolated from 56% of the samples, with the highest concentration, 24,000 MPN/g, occurring on day 12 at 12.8°C. === Master of Science