Evaluation of Lactobacillus sake contamination in vacuum-packaged sliced cooked meat products by ribotyping

Contamination of sliced cooked meat products with a Lactobacillus sake starter strain was suspected to cause spoilage in the products before the end of the expected shelf Life. The cooked products were sliced and vacuum packaged in the room in which a fermented product was handled. Since L. sake strains are known to be a dominant part of spoilage microflora associated with vacuum-packaged meat products, a contamination study was performed. One hundred and eighteen strains were isolated from six spoiled vacuum-packaged meat products and from the surfaces of the packaging room and adjacent refrigerators. DNA was isolated from these strains and cleaved using EcoRI and HindIII restriction endonucleases to obtain characteristic ribotypes. Corresponding ribotypes of the L. sake starter strain were compared by using EcoRI digestions to the 14 different patterns obtained from the strains growing in spoiled products and on surfaces. The L. sake starter strain was shown to contaminate the packaging room and it was also isolated from one of the products. However, it was not a dominant strain in this product and it could not be linked to the other products. Our results indicated that handling the fermented product in the refrigerating and packaging rooms together with cooked products was not the major cause of spoilage in these products.