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

摘要

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. Slicing and vacuum packaging of the cooked products was done in the room in which the fermented product was handled. Since L. sake strains are known to be a dominant part of spoilage microflora associated with vacuum-pack-aged meat products, a contamination study was performed. One hundred and eighteen strains were isolated from 6 spoiled vacuum packaged meat products and from the surfaces of the packaging room and adjac-ent refrigerators. DNA was isolated from these strains and cleaved using Eco RI and Hind III restriction endonucleases to obtain characteristic ribotypes. Corresponding ribotypes of the L. sake starter strain were compared to the 14 different patterns obtained from the strains growing in spoiled products and on surfaces by Eco RI digestions. 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.