Raw Materials of Cooked Ring Sausages as a Source of Spoilage Lactic Acid Bacteria

Vandamme

1998

Appl Environ Microbiol

110

Leuconostoc carnosum was shown to be the specific spoilage organism in vacuum-packaged, sliced, cooked ham showing spoilage during 3 weeks of shelf life. Identification of the specific spoilage organism was done by use of phenotypic data and ClaI, EcoRI, and HindIII reference strain ribopatterns. One hundred L. carnosum isolates associated with the production and spoilage of the ham were further characterized by pulsed-field gel electrophoresis (PFGE), together with some meat-associated Leuconostoc species: L. citreum, L. gelidum, L. mesenteroides subsp. dextranicum, and L. mesenteroides subsp. mesenteroides. ApaI and SmaI digests divided the industrial L. carnosum strains into 25 different PFGE types, ApaI and SmaI types being consistent. Only one specific PFGE type was associated with the spoiled packages. This type also was detected in air and raw-meat mass samples. The spoilage strain did not produce bacteriocins. Only seven isolates belonging to three different PFGE types produced bacteriocins. Similarity analysis of the industrial L. carnosum strains revealed a homogeneous cluster which could be divided into eight subclusters consisting of strains having at most three-fragment differences. The L. carnosum cluster was clearly distinguished from the other meatassociated leuconostoc clusters, with the exception of the L. carnosum type strain. Ribotyping can be very helpful in the identification of L. carnosum, but its discriminatory power is too weak for strain characterization. PFGE provides good discrimination for studies dealing with the properties of homogeneous L. carnosum strains.

Section: Discussionmentioning

confidence: 99%

Identification and Characterization of Leuconostoc carnosum , Associated with Production and Spoilage of Vacuum-Packaged, Sliced, Cooked Ham

Vandamme

1998

Appl Environ Microbiol

110

“…must be prevented from being transferred to other room s where the products are handled after cooking (51,53) . To…”

Section: Microbiological Contaminatio N Accumulation Of Slime and Milmentioning

confidence: 99%

Microbiological Spoilage and Contamination of Vacuum-Packaged Cooked Sausages

Journal of Food Protection

1997

Self Cite

121

Lactic acid bacteria are considered a major component of th e microbial population found on various types of vacuum-package d cooked sausages . Lactobacillus sake and Lactobacillus curvatu s have been shown to be common species in these products . L . sak e seems to form the predominant part of the spoilage population . Lactic acid bacterial growth on the surface of the sausage s produces undesirable sensory attributes, such as sour aroma an d taste . A specific spoilage phenomenon of commercial significance , characterized by long, stretchy, polysaccharide ropes betwee n sausages or sausage slices, has also been found . L . sake strains play a major role in this spoilage phenomenon as well . Cooking o f sausages during manufacturing destroys lactic acid bacteria on th e surface of the sausages . Sausages are recontaminated with spoilag e lactic acid bacteria mainly during the processing stages afte r 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 ra w 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 th e growth of spoilage microorganisms and to extend the shelf life o f vacuum-packaged sausages after packaging .

“…Products become recontaminated with LAB mainly during handling after the cooking process. LAB growth has been detected in the air, physical facilities, working surfaces, and workers' hands, and these sites have been assumed to be the sources of the spoilage LAB (9,17,18,25,26,30,32). There are, however, differences in the ability of different LAB species and strains to spoil meat products (8,11,13,14,16,20,23,29,31,(36)(37)(38)(39)(40)42).…”

mentioning

confidence: 99%

“…On the basis of LAB growth alone, it cannot be determined if a sample contains species or strains later associated with the spoilage of a product. Very few attempts have been made to study recontamination by the spoilage-causing LAB species and strains in particular (4,24,26,28). The sources of the spoilage LAB and the routes and sites of the recontamination in meat-producing plants are still poorly known.…”

mentioning

confidence: 99%

Use of rRNA gene restriction patterns to evaluate lactic acid bacterium contamination of vacuum-packaged sliced cooked whole-meat product in a meat processing plant

1997

Appl Environ Microbiol

Molecular typing was applied to an in-plant lactic acid bacterium (LAB) contamination analysis of a vacuum-packaged sliced cooked whole-meat product. A total of 982 LAB isolates from the raw mass, product, and the environment at different production stages were screened by restriction endonuclease (EcoRI and HindIII) analysis. rRNA gene restriction patterns were further determined for different strains obtained from each source. These patterns were used for recognizing the spoilage-causing LAB strains from the product on the sell-by day and tracing the sources and sites of spoilage LAB contamination during the manufacture. LAB typing resulted in 71 different ribotypes, of which 27 were associated with contamination routes. Raw material was distinguished as the source of the major spoilage strains. Contamination of the product surfaces after cooking was shown to be airborne. The removal of the product from the cooking forms was localized as a major site of airborne LAB contamination. Food handlers and some surfaces in contact with the product during the manufacture were also contaminated with the spoilage strains. Some LAB strains were also able to resist cooking in the core of the product bar. These strains may have an effect on the product shelf life by contaminating the slicing machine. The air in the slicing department and adjacent cold room contained very few LAB. Surface-mediated contamination was detected during the slicing and packaging stages. Food handlers also carried strains later found in the packaged product. Molecular typing provided useful information revealing the LAB contamination sources and sites of this product. The production line will be reorganized in accordance with these results to reduce spoilage LAB contamination.