Hazard analysis applied to microbial growth in foods: Development of mathematical models describing the effect of water activity

Broughall, J. M.; Anslow, P.A.; Kilsby, D. C.

doi:10.1111/j.1365-2672.1983.tb02653.x

Cited by 92 publications

(37 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Differences in embryo lethality among the strains were evaluated for statistical significance using a two-sample test of proportions (47). The growth rate of each E. coli strain was determined as described previously (3,10). All data were included from the point at which the cell concentration had increased to 150% of the inoculated concentration to the point at which the population density ceased to increase.…”

Section: Methodsmentioning

confidence: 99%

Acquisition of Avian PathogenicEscherichia coliPlasmids by a CommensalE. coliIsolate Enhances Its Abilities To Kill Chicken Embryos, Grow in Human Urine, and Colonize the Murine Kidney

et al. 2006

View full text Add to dashboard Cite

We have found an avian pathogenic Escherichia coli (APEC) plasmid, pAPEC-O2-ColV, which contains many of the genes associated with APEC virulence and also shows similarity in content to a plasmid and pathogenicity island of human uropathogenic E. coli (UPEC). To test the possible role of this plasmid in virulence, it was transferred by conjugation along with a large R plasmid, pAPEC-O2-R, into a commensal avian E. coli strain. The transconjugant was compared to recipient strain NC, UPEC strain HE300, and donor strain APEC O2 using various assays, including lethality for chicken embryos, growth in human urine, and ability to cause urinary tract infection in mice. The transconjugant killed significantly more chicken embryos than did the recipient. In human urine, APEC O2 grew at a rate equivalent to that of UPEC strain HE300, and the transconjugant showed significantly increased growth compared to the recipient. The transconjugant also significantly outcompeted the recipient in colonization of the murine kidney. These findings suggest that APEC plasmids, such as pAPEC-O2-ColV, contribute to the pathogenesis of avian colibacillosis. Moreover, since avian E. coli and their plasmids may be transmitted to humans, evaluation of APEC plasmids as possible reservoirs of urovirulence genes for human UPEC may be warranted.

show abstract

Section: Methodsmentioning

confidence: 99%

Acquisition of Avian PathogenicEscherichia coliPlasmids by a CommensalE. coliIsolate Enhances Its Abilities To Kill Chicken Embryos, Grow in Human Urine, and Colonize the Murine Kidney

et al. 2006

View full text Add to dashboard Cite

show abstract

“…Furthermore, it only had a direct influence on spoilage rate when water content was so low that the mobility of reactants was severely reduced. Broughall et al (1983) have made predictions oflag and generation times for Staphylococcus aureus and Salmonella typhimurium based on their observations ofthe growth kinetics of these organisms at different water activities and temperatures (Table 2.…”

Section: Aw=p/pomentioning

confidence: 99%

Preservation of fish by curing (drying, salting and smoking)

Horner¹

1997

Fish Processing Technology

View full text Add to dashboard Cite

Curing, as a means of preserving fish, has been practised perhaps longer than any other food preservation technique. Marine fish bones found in cave dwellings, inhabited 20000 years ago and situated many days' walk from the coast of Spain, indicate some form of curing, probably by drying in the open air. Salting, smoking and drying have all continued as preservation techniques virtually unaltered from prehistory to the present day. Modern developments have centred around understanding and controlling the processes to achieve the standardised product demanded by today's market. A major exception has been exploitation of the sublimation of ice to dry food so that it resembled the starting material in volume and shape. This only became possible with the development of pumps which could create, and valve seals which could maintain, high vacuum.None the less, for all the developments in cure-processing accommodating continuous production lines, the time required to achieve a long shelf-life product purely by water removal is much greater than for any other commonly used preservation method. This is because the process relies upon the diffusion rate of either water from the centre of the food to its surface, or the diffusion rate of salt (or other solute) in the opposite direction, or a combination of both. Water content, water activity (a w ) and storage stabilityUnlike canning, which engenders the destruction of micro-organisms and their spores, curing preserves by rendering the medium an unsuitable environment for microbial propagation. Increasing the concentration of soluble substances in the medium either by abstracting water or by causing soluble substances to diffuse in (salting, brining or sugar curing) are the principal means of accomplishing this. In addition to concentrating the soluble substances by brining and dehydration, smoking preserves by depositing bacteriostatic chemicals like formaldehyde and phenols in the system.The addition of salt is more effective weight for weight than the addition of sugar because salt ionises to a sodium cation and a chloride anion each of G. M. Hall (ed.), Fish Processing Technology

show abstract

“…), estimated from published growth kinetics were obtained by fitting the logistic with delay growth model (Kono 1968;Broughall et al 1983;Rosso et al 1996;Augustin and Carlier 2000a;Pinon et al 2004). Differences between estimations were often observed depending on the primary growth model used (Augustin and Carlier 2000a;McKellar and Lu 2004).…”

Section: Growth Data Of L Monocytogenesmentioning

confidence: 99%

Growth rate and growth probability of Listeria monocytogenes in dairy, meat and seafood products in suboptimal conditions

et al. 2005

View full text Add to dashboard Cite

Aims: To evaluate the performances of models predicting the growth rate or the growth probability of Listeria monocytogenes in food. Methods and Results: Cardinal and square root type models including or not interactions between environmental factors and probability models were evaluated for their ability to describe the behaviour of L. monocytogenes in liquid dairy products, cheese, meat and seafood products. Models excluding interactions seemed sufficient to predict the growth rate of L. monocytogenes. However, the accurate prediction of growth/no-growth limits needed to take interactions into account. A complete and a simplified form (preservatives deducted) of a new cardinal model including interactions and parameter values were suggested to predict confidence limits for the growth rate of L. monocytogenes in food. This model could also be used for the growth probability prediction. Conclusions: The new cardinal model including interactions was efficient to predict confidence limits for the growth rate of L. monocytogenes and its growth probability in liquid dairy products, meat and seafood products. In cheese, the model was efficient to predict the absence of growth of the pathogen. Significance and Impact of the Study: The suggested model can be used for risk assessment and risk management concerning L. monocytogenes in dairy, meat and seafood products.

show abstract

Hazard analysis applied to microbial growth in foods: Development of mathematical models describing the effect of water activity

Cited by 92 publications

References 19 publications

Acquisition of Avian PathogenicEscherichia coliPlasmids by a CommensalE. coliIsolate Enhances Its Abilities To Kill Chicken Embryos, Grow in Human Urine, and Colonize the Murine Kidney

Acquisition of Avian PathogenicEscherichia coliPlasmids by a CommensalE. coliIsolate Enhances Its Abilities To Kill Chicken Embryos, Grow in Human Urine, and Colonize the Murine Kidney

Preservation of fish by curing (drying, salting and smoking)

Growth rate and growth probability of Listeria monocytogenes in dairy, meat and seafood products in suboptimal conditions

Contact Info

Product

Resources

About