Gr. Siragusa et al., Incorporation of bacteriocin in plastic retains activity and inhibits surface growth of bacteria on meat, FOOD MICROB, 16(3), 1999, pp. 229-235
The bacteriocin, nisin, was incorporated into a polyethylene based plastic
film and retained activity against the indicator bacteria Lactobacillus hel
veticus and Brochothrix thermosphacta. Beef carcass surface tissue sections
(BCT) topically inoculated with the psychrotrophic spoilage bacterium B. t
hermosphacta were vacuum-packaged both with and without wrapping with the n
isin impregnated plastic and held at 4 degrees C. An initial reduction of 2
log(10) cycles of B. thermosphacta was observed with nisin-impregnated wra
pped BCT within the first 2 days of storage. After 20 days of refrigerated
storage B. thermosphacta populations from nisin impregnated plastic wrapped
samples were significantly less than (P < 0.05) control vacuum-packaged sa
mples; log(10)5.8 vs 7.2 cfu cm(-2) respectively Temperature abuse was simu
lated by shifting inoculated packs from 4 degrees C (after 2 days) to 12 de
grees C. Again, by 20 days, the B, thermosphacta populations of treated sam
ples wrapped with nisin impregnated plastic were significantly less than (P
< 0.05) control vacuum-packaged samples. log(10)3.6 vs 6.3 cfu cm(-2) resp
ectively. This work highlights the potential for incorporating antimicrobia
l peptides with a wider and different range of inhibitory activity directly
into plastics of different properties for use in controlling food spoilage
as well as preservation to enhance product microbial safety (C) 1999 US Go
vernment.