Survival of Listeria monocytogenes, and other food spoilage microbes in vacuum packaged West African soft cheese 'wara'

Abstract

'Wara'soft cheese is traditionally produced in Nigeria and has a poor microbial quality. This study assessed the survivability of Listeria monocytogenes and other food spoilage microbes (enterobacteriacea, molds and yeasts) in vacuum packaged soft cheese treated independently with Carica papaya (Vcpc), Tenninalia cattapa (Vtcc) crude extracts, nisin (Vnc), and the combination of these three treatments (V+3) stored at 15°C and 28°C for a three week storage period. Vacuum packaging did not suppress Listeria monocytogenes, and there were no significant difference s in the L. monocytogenes counts throughout the storage weeks (P>0.05). The enterobacteriacea counts were suppressed to undetectable levels at 15°C storage temperature by the third week of storage in all treatments except the Vnc and V+3. Molds and yeasts were undetectable in all treatments throughout the storage weeks.Significant differences occurred in the microbial count at the two storage temperatures and storage weeks (P<0.05). It can therefore be concluded from this work that Vacuum packaging and addition of crude extracts (Carica papaya, Terminalia cattapa) in soft cheese storage can suppress enterobacteriacea, molds and yeasts. Food technologists developing industrialized 'wara should consider including these extracts and vacuum packaging in their production. Therefore, their use in extension of the shelf-life of soft cheese is recommended.