ISSN:
1745-4565
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Clostridium perfringens growth from a spore inoculum was investigated in vacuum-packaged, cook-in-bag ground beef that included 0.3% (w/w) sodium pyrophosphate, pH 5.5 or 7.0, and salt (sodium chloride) at 0 or 3% (w/w). The packages were processed to an internal temperature of 71.1C, ice chilled and stored at various temperatures. The total C. perfringens population was determined by plating diluted samples on tryptose-sulfite-cycloserine agar followed by anaerobic incubation for 48 h at 37C. At 28C, a combination of 3% salt and pH 5.5 was effective in delaying growth for 24 h. At 15C, growth occurred within 6 days in samples with pH 7.0, but was delayed until day 8 in the presence of 3% salt at pH 7.0. Vegetative cells were not observed even after 21 days 21 of storage at 15C in the presence 3% salt at pH 5.5. C. perfringens growth was not observed at 4C regardless of pH or salt levels. The D-values ranged from 23.33 min (3% salt, pH 7.0) to 13.99 min (3% salt, pH 5.5). Cyclic and static temperature abuse of refrigerated products for 12–15 h did not permit C. perfringens growth. However, temperature abuse of cook-in-bag beef products for periods longer than 15 h in the absence of salt led to growth of C. perfringens from a spore inoculum.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1745-4565.1995.tb00118.x
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