Bacteriological Survey and Refrigerated Storage Test of Vacuum-Packed Sliced Imported Canned Ham

At the time of slicing and packaging, 179 of 180 retail-sized vacuum-packed sliced ham samples collected from 12 establishments had aerobic plate counts of 2,000 or fewer/g. Coliforms were isolated from only three of the samples, and all samples were negative for Escherichia coli , Staphylococcus aureus , and salmonellae. When stored at 3 C, bacterial growth in vacuum-packed, sliced ham proceeded at a rate similar to that of non-vacuum-packed, cross-sections cut from hams just before slicing. However, after 68 days of refrigerated storage, there was no bacterial growth in a non-vacuum-packed, cross-section cut from a ham removed from a can with strict aseptic techniques. These results suggest that the slight contamination upon opening canned hams by conventional methods may have as great an effect on the bacteriological stability of sliced ham as any additional slight contamination from the slicing-packaging operation.