Interrelationship between microbial numbers and other parameters in the spoilage of vacuum-packed cooked ring sausages

Korkeala, Hannu; Lindroth, S.; Ahvenainen, Raija; Alanko, Timo

doi:10.1016/0168-1605(87)90045-6

Cited by 60 publications

(23 citation statements)

References 8 publications

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“…LAB counts increased from 10 2 to 10 6 CFU/g after 14 days at 8°C and 6 weeks at 2°C, while total bacterial counts reached 10 5 CFU/g; both populations had a lower growth rate at 2°C. The dominance of LAB in meat is consistent with their ability to multiply under low oxygen concentrations and chilled conditions, with their growth rate accelerating as the temperature increases (20,30). In this work, LAB counts were rather lower than the ones reported for vacuum-packaged beef stored for 6 to 8 weeks at temperatures between Ϫ1.5 and 4°C, with final counts of 10 7 to 10 8 CFU/g (5,19,28).…”

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confidence: 44%

Direct Molecular Approach to Monitoring Bacterial Colonization on Vacuum-Packaged Beef

Fontana

Cocconcelli

Vignolo

2006

Appl Environ Microbiol

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Denaturing gradient gel electrophoresis allowed us to monitor total bacterial communities and to establish a pattern of succession between species in vacuum-packaged beef stored at 2 and 8°C for 9 weeks and 14 days. Species-specific PCR was used to confirm the presence of Lactobacillus sakei and Lactobacillus curvatus. Multiplex PCRs using 16S rRNA-specific primers allowed differentiation between Leuconostoc species. These methods provided the desired information about microbial diversity by detecting the main microorganisms capable of colonizing this ecological niche.Vacuum packaging under chilled conditions has proved very effective in extending the shelf life of perishable foods, such as fresh meat and meat products, and preventing the growth of food-borne pathogens (8). The oxygen supply will be restricted, depending on the gas permeability of the packaging film, and thus has a selective effect on the microbial population (22). Lactic acid bacteria (LAB), such as Lactobacillus spp., Leuconostoc spp., Carnobacterium spp., and Brochothrix thermosphacta, are the main spoilage organisms associated with chilled vacuum-packaged fresh-meat products (6,18,21,26,33). Shortly after vacuum packaging of meat, LAB populations are usually below the routine detection limit (Ͻ10 CFU/g), but they increase during storage (19). Although LAB can cause meat spoilage, a selective growth promotion of LAB capitalizing on their ability to control meat-borne pathogens with a preferential growth of benign strains would minimize their spoilage effects (7,25,32,34).Methods in molecular microbiology, especially those including the sequencing of genes coding for 16S rRNA, have become a very important tool in the study of bacterial communities in meat samples. The trend is toward culture-independent methods, because they are believed to overcome problems associated with selective cultivation and isolation of bacteria from natural samples. Genetic-fingerprinting techniques provide a profile representing the genetic diversity of a microbial community from a specific environment. Denaturing gradient gel electrophoresis (DGGE) is usually employed to assess the structure and dynamics of microbial communities in food samples without cultivation in response to environmental variations (13,14,15,27). Species-specific PCR is a rapid and reliable molecular technique for the characterization of bacterial communities, and it can be also applied in situ without colony isolation (2). The variations in length and sequences of the 16S/23S rRNA intergenic spacer regions of the rRNA operon have proved useful for strain and species identification (2,3,17). In this work, we describe the application of cultureindependent methods to the study of the microbial succession dynamics in vacuum-packaged beef stored at 2 and 8°C for 9 weeks and 14 days, respectively.Bacterial control strains and growth conditions. Lactobacillus sakei CRL1463, Lactobacillus curvatus CRL 1465, and Leuconostoc gelidum CRL 1542 (CERELA culture collection) were used as reference strains. L...

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confidence: 44%

Direct Molecular Approach to Monitoring Bacterial Colonization on Vacuum-Packaged Beef

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Cocconcelli

Vignolo

2006

Appl Environ Microbiol

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“…It is generally known that lactic acid bacteria can 6 .3 . Once the lactic acid bacteria reached a population o f produce sensory changes as well as changes in physical 6 X 10' CFU/g, the pH decreased sharply (38,41) . Sample s appearance in spoiled vacuum-packaged sausages (Table 1) .…”

Section: Spoilage Of Sausagesmentioning

confidence: 99%

“…Sen-sausages are found to be especially spoiled . In vacuumsory changes are produced by lactic acid bacterial growth on packaged vienna sausages, the mean pH values decrease d the surface of the sausages (37,40,41,42,89). In addition to from 6 .1 (unspoiled samples) to 4 .8 to 4 .6 (spoiled samples) the sensory changes in the sausages, changes in the drip (88) .…”

Section: Spoilage Of Sausagesmentioning

confidence: 99%

Microbiological Spoilage and Contamination of Vacuum-Packaged Cooked Sausages

Korkeala

Björkroth

1997

Journal of Food Protection

123

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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 .

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“…CFU/ml in the substrate. The latter microbial concentration has been either reported as the spoilage level or related to the end of the shelf lives of many food products spoiled by lactic acid bacteria or other bacterial groups (7,9,19,22,23,30,39,43,45). With respect to the variation in color of the TTI system, repeated experiments to determine ⌬⌭ values throughout the course of the culture's growth (initial inoculum level, 10 2 CFU/ml) showed a mean value of 15.2% for the coefficients of variation for all sampling time intervals.…”

Section: Resultsmentioning

confidence: 99%

“…It is well known that the shelf lives of most chilled high-protein foods are linked to the growth and metabolic activities of the "specific spoilage organisms" (SSO; the fraction of the total microflora responsible for spoilage); indeed, the sensory rejection of such products is observed when the SSO reach a certain population level called the "spoilage level" (21)(22)(23). For example, the quality loss of most chilled meat products packed under vacuum or modified-atmosphere conditions is based on the growth and metabolic activities (acid production) of lactic acid bacteria, which result in an unacceptable sour/acidic/ cheesy odor when the bacterial population approaches the level of 10 7 to 10 8 CFU/g (4,8,9,19,30,34,37). It is also worth noting that the specific dominance of the L. sakei group in the spoilage microbial flora of these products has been demonstrated in several studies (8,9,37).…”

Section: Vol 74 2008 Microbial Tti For Monitoring Quality Of Chillementioning

confidence: 99%

Development of a Microbial Time/Temperature Indicator Prototype for Monitoring the Microbiological Quality of Chilled Foods

Vaikousi

Βiliaderis

Koutsoumanis

2008

Appl Environ Microbiol

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A time/temperature indicator (TTI) system based on the growth and metabolic activity of a Lactobacillus sakei strain was developed for monitoring food quality throughout the chilled-food chain. In the designed system, an irreversible color change of a chemical chromatic indicator (from red to yellow) progressively occurs due to the pH decline that results from microbial growth and metabolism in a selected medium. The relation of the TTI response (color change) to the growth and metabolic activity (glucose consumption, lactic acid production, pH decrease) of L. sakei was studied. In addition, the temperature dependence of the TTI kinetics was investigated isothermally in the range of 0 to 16°C and modeled with a system of differential equations. At all temperatures tested, the pH and color changes of the TTI system followed closely the growth of L. sakei, with the endpoint (the time at which a distinct visual color change to the final yellow was observed) of the TTI coinciding with a population level of 10 7 to 10 8 CFU/ml. The endpoint decreased from 27 days at 0°C to 2.5 days at 16°C, yielding an activation energy of 97.7 kJ/mol, which was very close to the activation energy of the L. sakei growth rate in the TTI substrate (103.2 kJ/mol). Furthermore, experiments conducted on the effect of the inoculum level showed a negative linear relationship between the level of L. sakei inoculated in the system medium and the endpoint of the TTI. For example, the endpoint at 8°C ranged from 6 to 2 days for inoculum levels of 10 1 and 10 6 CFU/ml, respectively. This relationship allows the easy adjustment of the TTI endpoint at a certain temperature according to the shelf life of the food product of concern by using an appropriate inoculum level of L. sakei. The microbial TTI prototype developed in the present study could be used as an effective tool for monitoring shelf life during the distribution and storage of food products that are spoiled primarily by lactic acid bacteria or other bacteria exhibiting similar kinetic responses and spoilage potentials. Apart from the low cost, the main advantage of the proposed TTI is that its response closely matches the loss of the quality of a food product by simulating the microbial spoilage process in particular environments.A modern quality and safety assurance system should prevent contamination through the monitoring, recording, and controlling of critical parameters during a product's entire life cycle, which includes the postprocessing phase and extends over the time of use by the final consumer (20). Since temperature is the parameter that predominantly determines the shelf life and final quality and safety of food products after their processing according to Good Manufacturing Practices and Good Hygiene Practices, monitoring and recording the temperature conditions during distribution and storage are of crucial importance (40,41). Time/temperature indicators or integrators (TTIs) are used as cost-effective and user-friendly devices to monitor, record, and translate the overa...

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Interrelationship between microbial numbers and other parameters in the spoilage of vacuum-packed cooked ring sausages

Cited by 60 publications

References 8 publications

Direct Molecular Approach to Monitoring Bacterial Colonization on Vacuum-Packaged Beef

Direct Molecular Approach to Monitoring Bacterial Colonization on Vacuum-Packaged Beef

Microbiological Spoilage and Contamination of Vacuum-Packaged Cooked Sausages

Development of a Microbial Time/Temperature Indicator Prototype for Monitoring the Microbiological Quality of Chilled Foods

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