Probiotic properties and stress response of thermotolerant lactic acid bacteria isolated from cooked meat products

ABSTRACT Three kinds of lactic acid bacteria were isolated from spoiling cooked meat products stored below 10Ã¯Â¿Â½C. They were identified as Leuconostoc mesenteroides subsp. mesenteroides, Lactococcus lactis subsp. lactis, and Leuconostoc citreum. All three strains grew well in MRS broth at 10Ã¯Â¿Â½C. In particular, L. mesenteroides subsp. mesenteroides and L. citreum grew even at 4Ã¯Â¿Â½C, and their doubling times were 23.6 and 51.5 h, respectively. On the other hand, although the bacteria were initially below the detection limit (<10 CFU/g) in model cooked meat products, the bacterial counts increased to 108 CFU/g at 10Ã¯Â¿Â½C after 7 to 12 days.

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Cooked meat products made of coarsely ground pork: the main bacterial strains of bacterial flora, their heat resistance and effect on spoilage

Agricultural and Food Science ◽

10.23986/afsci.72667 ◽

1993 ◽

Vol 2 (5) ◽

pp. 413-421

Author(s):

Esko Petäjä ◽

Eero Puolanne

Keyword(s):

Surface Layer ◽

Lactic Acid ◽

Lactic Acid Bacteria ◽

Bacterial Flora ◽

Meat Products ◽

Bacterial Strains ◽

The Core ◽

Ground Pork ◽

Cooked Meat ◽

Cooked Meat Products

This study was conducted to investigate the bacterial flora of the surface layer and the core of meat products made of coarsely ground pork at the moment of spoilage when stored at 7°C or 4°C. The dominating strains were isolated, their heat resistance was studied in APT-broth, on APT-agar and in coarsely ground cured pork, and their growth after heating and effect on spoilage were followed in coarsely ground cured pork. The first signs of spoilage appeared in the surface layer of the products. The strains were coccoid lactic acid bacteria with counts ranging from 3,5 to 7.8 log cfu (colony forming units)/g. They survived only accidentally after heating for 15 minutes at 72°C in APT-broth. The core of the products contained only coccoid lactic acid bacteria or only pseudomonads or both as the main bacterial strains. The counts ranged from 2.6 to 6.0 log cfu/g. Most of the strains isolated from the core survived after heating for 30 minutes at 72°C in APT-broth in at least three tests out of six. The most noticeable result of the study was the occurence of heat-resistant pseudomonads in the core. It must be pointed out that all pseudomonads found survived after heating for 60 minutes at 72°C in APT-broth, and often after heating for 15 minutes at 72°C in coarsely ground cured pork (core 72°C). The cfu number of the two most heat-resistant streptococcus strains decreased only 1 log unit over 15 minutes at 72°C in coarsely ground cured pork. The numbers of inoculated pseudomonads decreased but those of streptococci rose by a maximum of 1 log unit when the experimental porks were kept at 4°C after heating. This indicates that streptococci and pseudomonads probably do not constitute a serious spoilage factor in cooked meat products, but spoilage is generally effected by bacteria which have contaminated the surface layer of the products after heat treatment.

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Characterization and Growth under Different Storage Temperatures of Ropy Slime–Producing Leuconostoc mesenteroides Isolated from Cooked Meat Products

Journal of Food Protection ◽

10.4315/jfp-19-521 ◽

2020 ◽

Vol 83 (6) ◽

pp. 1043-1049

Author(s):

BENIAMINO T. CENCI-GOGA ◽

PAOLA SECHI ◽

MARIA F. IULIETTO ◽

SHAHIN AMIRJALALI ◽

SALVATORE BARBERA ◽

...

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Leuconostoc Mesenteroides ◽

Meat Products ◽

Bacterial Concentration ◽

De Man ◽

Cooked Meat ◽

Storage Temperatures ◽

Lactobacillus Spp ◽

Cooked Meat Products

ABSTRACT The presence of lactic acid bacteria can be detrimental when the abundant growth of slime-producing strains (Lactobacillus spp. and Leuconostoc spp.) causes spoilage of meat products. Two strains of lactic acid bacteria were isolated from vacuum-packed cooked hams that had been withdrawn from the market for the so-called ropy slime defect and identified as Leuconostoc mesenteroides. In an attempt to define the behavior of ropy slime–producing bacteria, two strains of L. mesenteroides were incubated in de Man Rogosa Sharpe broth at different storage temperatures and conditions of thermal abuse (4, 12, 20, 30, 37, and 44°C). Both strains showed a lack of growth at 44°C, a good level of development at 30 and 37°C, and evident growth ability at low temperatures, with a long stationary phase. In particular, the bacterial concentration at 4°C was >105 CFU mL−1 after more than 120 days of incubation. This study demonstrates that the refrigeration temperature for cooked meat products does not constitute a hurdle for ropy slime producers and their subsequent ability to spoil. HIGHLIGHTS

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Fermented Sausage as a Contamination Source of Ropy Slime-Producing Lactic Acid Bacteria

Journal of Food Protection ◽

10.4315/0362-028x-55.1.48 ◽

1992 ◽

Vol 55 (1) ◽

pp. 48-51 ◽

Cited By ~ 10

Author(s):

PIA M. MÄKELÄ

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Meat Products ◽

Contamination Source ◽

Fermented Sausage ◽

Potential Source ◽

Fermented Sausages ◽

Cooked Meat ◽

Cooked Meat Products

The ability of four ropy slime-producing lactic acid bacteria strains to multiply during the manufacture of Finnish fermented sausages was studied. Two of the three lactobacilli strains studied were able to compete with the starter bacteria used, and these lactobacilli occurred in high levels in the sausages at the end of manufacture. The Leuconostoc strain studied was found only once during the manufacture. Since fermented sausages in Finland are commonly handled in the same rooms as cooked meat products, the fermented sausages form a potential source of the ropy slime-producing lactobacilli for cooked products.

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Microbiological hazards at several stages of production and distribution of cooked sausages

Journal of the Hellenic Veterinary Medical Society ◽

10.12681/jhvms.15375 ◽

2018 ◽

Vol 53 (3) ◽

pp. 201

Author(s):

D. SERGELIDIS (Δ. ΣΕΡΓΚΕΛΙΔΗΣ) ◽

A. ABRAHIM (Α. AMIN) ◽

A. SARIMVEI (Α. ΣΑΡΗΜΒΕΗ) ◽

C. GENIGEORGIS (Κ. ΓΕΝΗΠΩΡΓΗΣ)

Keyword(s):

Lactic Acid ◽

Thermal Treatment ◽

Lactic Acid Bacteria ◽

Pathogenic Bacteria ◽

Meat Products ◽

Salmonella Spp ◽

E Coli ◽

Spoilage Bacteria ◽

Cooked Meat ◽

Cooked Meat Products

Fifty one (51) samples of several types of cooked sausage paste, prepared by two meat factories in N. Greece were examined. TPC of these samples ranged between 5,3-6,3 Log10CFU/g. Coliforms were regularly present reaching populations of 93->2.400 MPN/g and lactic acid bacteria ranged between 5-6,3 Log10CFU/g. L. monocytogenes was detected in 56 and 38,4% of the samples collected in each factory. E. coli was detected in 20 and 16,6%, and Salmonella spp in 12 and 16,6% respectively. Neither pathogens nor coliforms were detected in 51 samples of cooked sausages originated from the same pastes examined before. No recovery of any injured cells of the pathogenic bacteria and coliforms was observed after their storage at 4°C for 20 days. TPC of the cooked sausage samples, after thermal treatment, ranged between 3-4,7 Log10CFU/g and consisted mainly of lactic acid bacteria (range <2-4,5 Log10CFU/g) and sporeformers (range 3-4,5 Log10CFU/g). After 20 days storage at 4°C the TPC and lactid acid bacteria counts of the cooked sausages, increased by <1 Log. We also examined 16 surface and center samples of cooked sausages and meat products without casings, consisting of big meat pieces (bacon, smoked ham,etc). Surface TPC ranged between 5-5,3 Log10CFU/g and from the center of the meats they ranged between 2-3,5 Log1 0CFU/g. Coliforms, E. coli, L. monocytogenes and Salmonella spp were not detected. Lactic acid bacteria were the main flora. Furthermore we examined surface samples of cooked meat products, without casings, during several stages following thermal treatment and up to storage for 24 h at 4° C, without any protective package. TPC immediately after thermal treatment were <2 Log^CFU/g, after cooling with water increased they increased at 3 Log10CFU/g and remained the same during the following 24 h storage at 4°C. Coliforms were detected in the stored products. Their populations exceeded 2.400 MPN/g on the surface of the samples after storage for a few days at 4°C. It is assumed that the flora on the surface of these products originated from the environment and the cooling water. Finally we examined 69 samples from surfaces of the slicing and packaging equipment of cooked meat products in 3 meat factories and 28 samples from 12 super markets. L. monocytogenes was detected in 6 and 14,2% of the samples that originated from the slicing blades in the factories and super markets respectively. The results of this study underline the importance of GMP for the prevention of contamination of cooked sausages with pathogens and the control of the growth of the spoilage bacteria population which minimize the self life of these products. This is especially true after thermal treatment during peeling and slicing.

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