Dm. Broda et al., PREVALENCE OF COLD-TOLERANT CLOSTRIDIA ASSOCIATED WITH VACUUM-PACKED BEEF AND LAMB STORED AT ABUSIVE AND CHILL TEMPERATURES, New Zealand Journal of Agricultural Research, 40(1), 1997, pp. 93-98
A survey was conducted for the presence of cold-tolerant (i.e. capable
of growing at less than 5 degrees C) Clostridium spp, in fresh vacuum
-packed beef and lamb obtained from nine export meat plants. Prevalenc
e was determined before and after storage at abusive (15 degrees C) an
d non-abusive (-1.5 degrees C) temperatures, and instances of pack fai
lure by ''blowing'' were recorded. Overall, only three samples (6.7%)
were positive for the presence of this group of micro-organisms on ini
tial testing. After storage at 15 degrees C for 8 weeks, cold-tolerant
clostridia were found in 51.1% of samples, all of which had ''blown''
. After storage at -1.5 degrees C for 12 weeks, only 2 samples (4.4%)
accumulated significant amounts of gas, and both contained cold-tolera
nt clostridia. With vacuum-packed product stored at 15 degrees C, appr
oximately 29% of the clostridial strains isolated at 15 degrees C were
cold-tolerant species capable of growing at less than 5 degrees C. Ho
wever, none of them were able to grow at -1.5 degrees C. Only psychrop
hilic and psychrotrophic clostridia were isolated from fresh samples a
nd those stored at -1.5 degrees C.