US researchers have found that growth of Listeria on ready-to-eat(RTE)meat can be restricted when it is packaged with an oxygen scavenger or carbon dioxide generator.
Jinru Chen and Aaron Brody of University of Georgia carried out the study.About 25g of cooked ham samples,inoculated with a mixture of five strains of Listeria monocytogenes(2 or 4 log CFU g-1),were packaged into three antimicrobial packaging formats and one sample to serve as controls was kept in a non-antimicrobial packaging format,reported Foodproductiondaily.com.
The samples were then stored at 4,10,or 22°C,and populations of total aerobic bacteria,Enterobacteriaceae,and inoculated L.monocytogenes were analysed twice in a week during the one-month storage period.
It was found that the packaging structures with the carbon dioxide generator and oxygen scavenger effectively restricted L.monocytogenes growth on the samples.
However,in the control packaging format,the average populations of L.monocytgenes grew from the actual 2 log CFU g-1 inoculation level to 2.84,5.21 and 6.42 log CFU g-1 at 4,10,and 22 days of the storage period.
