Survial of Listeria monocytogenes during the manufacture and ripening of Turkish White cheese

Listeria monocytogenes was enumerated during the manufacture and ripening o f Turkish White cheese with particular reference to a) pasteurized milk, b) cheese milk after inoculation with L. monocytogenes (0 h), c) after curd f ormation (2 h), d) curd after pressing (6 h), e) curd after pH was reduced (17 h), f) curd after salting (32 h), and g) cheeses during ripening. Chees es were also examined periodically for total solids, moisture and salt cont ents, pH values and aerobic plate count. An increase in the number of L. mo nocytogenes was observed during manufacture. Following salting and througho ut the storage period, numbers of L. monocytogenes decreased at a rate depe nding on the salt concentration, starter activity and storage time. The ini tial microbial number had a significant (P < 0.01) effect on the survival o f L. monocytogenes during the storage period.