INFLUENCE OF UNSLICED DELICATESSEN MEAT FRESHNESS UPON BACTERIAL-GROWTH IN SUBSEQUENTLY PREPARED VACUUM PACKED SLICES

Unsliced beef pastrami, reformulated ham and bologna held at 6 degrees C were sliced 21, 17, 12 or 7 days before or at the assigned manufact urer's best before date and Vacuum packaged. Packages of sliced meats were field at 6 degrees C for another 7, 12, 17 or 21 days, opened and analyses made for total bacteria, lactic acid bacteria, Enterobacteri aceae and Brochothrix thermosphacta. The maximum storage interval was 42 days; half this period unsliced, the remainder as repacked slices. Numbers of bacteria on pastrami were significantly greater than on ham and bologna (pastrami > ham > bologna) with the lactic acid bacteria dominating in all products. As unsliced meats approached their best be fore date, insignificant increases were generally noted for numbers of lactic bacteria, Enterobacteriaceae and B. thermosphacta. During subs equent storage of slices under vacuum, numbers of total and lactic bac teria increased exponentially at the same rate while B. thermosphacta growth was significantly slower. Numbers of Enterobacteriaceae remaine d low and were essentially unchanged during sliced meat storage, Withi n the context of study storage parameters, shelf-life appeared to be d etermined by length of time after slicing and repackaging rather than by best before date of the unsliced meat. Packages of sliced meat prep ared from wholesale unsliced meats with 21 days left until their best before date or from unsliced meats with 12 days left until their best before date showed similar bacterial levels 21 days later. It was prob able that the localization of bacterial growth at the meat surface-pac kaging film interface of the unsliced meats yielded slices with initia lly lowered bacterial content when repackaged and sampled from the upp ermost slice. When Enterobacteriaceae and B. thermosphacta were absent from unsliced meats, extension of sliced meat meant package shelf-lif e beyond the best before date of the parent meant was possible. Howeve r, these bacterial groups were not always undetected.