Microbiological Spoilage and Contamination of Vacuum-Packaged Cooked Sausages

Lactic acid bacteria are considered a major component of the microbial population found on various types of vacuum-packaged cooked sausages. Lactobacillus sake and Lactobacillus curvatus have been shown to be common species in these products. L. sake seems to form the predominant part of the spoilage population. Lactic acid bacterial growth on the surface of the sausages produces undesirable sensory attributes, such as sour aroma and taste. A specific spoilage phenomenon of commercial significance, characterized by long, stretchy, polysaccharide ropes between sausages or sausage slices, has also been found. L. sake strains play a major role in this spoilage phenomenon as well. Cooking of sausages during manufacturing destroys lactic acid bacteria on the surface of the sausages. Sausages are recontaminated with spoilage lactic acid bacteria mainly during the processing stages after cooking. During the chilling process, product contamination apparently results from exposure to airborne microorganisms. Workers and equipment are among the most likely sources of contamination during packaging and slicing. Spoilage strains originating from raw material may spread to other areas in the production facility (i.e., chill, slicing, and packaging rooms) via the air, workers and equipment. Decontamination methods can be used to prevent the growth of spoilage microorganisms and to extend the shelf life of vacuum-packaged sausages after packaging.