THE BEHAVIOR OF LISTERIA-MONOCYTOGENES IN VACUUM-PACKED SLICED CHINESE SPICED BEEF

Sliced Chinese spiced beef was inoculated with a mixture of three stra ins of Listetria monocytogenes (serotype 4b, 1/2a and 1/2c). All sampl es were vacuum-packed after inoculation. Growth of L. monocytogenes wa s studied in samples stored at 4 degrees C, 7 degrees C and 15 degrees C. Generally speaking L. monocytogenes behaved in much the same way i n all the samples during the entire storage time. In the samples inocu lated with 5.43 log L. monocytogenes/g, the pathogen increased more th an 100-fold during 12 days of storage, whereas in samples inoculated w ith <2.00 log L. monocytogenes/g, the increase was more than 1,000,000 -fold, irrespective of the Storage temperature. This shows that vacuum -packed sliced Chinese spiced beef provides an ideal environment for t he growth of the pathogen. Effective measures should therefore be take n when processing Chinese spiced beef to control contamination by L. m onocytogenes. In the meantime, if the health of the consumer is to be protected, a study should be made of safe and economic methods that mi ght eliminate or inhibit this pathogen in the product concerned.