Proteolysis in UHT milk due to Staphylococcus aureus

The aim of this project was to analyse the effect of mastitis pathogen Staphylococcus (S.) aureus on proteolysis in UHT milk. S. aureus is one of the main pathogens that causes mastitis and reduces milk yield and quality which both leads to large economical losses. UHT milk was inoculated with four...

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Detalles Bibliográficos
Autor principal: Crnadak, Ninoslava
Formato: H2
Lenguaje:Inglés
Publicado: SLU/Dept. of Animal Nutrition and Management (until 231231) 2012
Materias:
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author Crnadak, Ninoslava
author_browse Crnadak, Ninoslava
author_facet Crnadak, Ninoslava
author_sort Crnadak, Ninoslava
collection Epsilon Archive for Student Projects
description The aim of this project was to analyse the effect of mastitis pathogen Staphylococcus (S.) aureus on proteolysis in UHT milk. S. aureus is one of the main pathogens that causes mastitis and reduces milk yield and quality which both leads to large economical losses. UHT milk was inoculated with four strains of S.aureus and then incubated at 37oC. Milk was sampled at six different time points (0, 0.5, 1, 2, 4, and 6 h). Samples were stored at -200C until analysis for protein separation by capillary electrophoresis (CE). CE was run for two strains (333 and 485) and electropherograms were obtained. Due to the quality of electropherograms only strain 485 was further evaluated for protein quantification. The level of milk proteins (caseins and whey proteins) was estimated for each sample by quantification of peak area. Data were statistically analysed using SAS ANOVA procedures. The lowest pH value of inoculated milk was 6.2, while pH of non-inoculated milk remained constant and was 6.7. Bacterial growth in log phase reached levels of 8x10 8 and 8.7x10 8 colony forming units for strain 333 and 485, respectively. The overall casein content was reduced by up to 21% due to S. aureus.
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id RepoSLU6351
institution Swedish University of Agricultural Sciences
language Inglés
publishDate 2012
publishDateSort 2012
publisher SLU/Dept. of Animal Nutrition and Management (until 231231)
publisherStr SLU/Dept. of Animal Nutrition and Management (until 231231)
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spelling RepoSLU63512014-01-15T14:08:57Z Proteolysis in UHT milk due to Staphylococcus aureus Crnadak, Ninoslava milk protein proteolysis The aim of this project was to analyse the effect of mastitis pathogen Staphylococcus (S.) aureus on proteolysis in UHT milk. S. aureus is one of the main pathogens that causes mastitis and reduces milk yield and quality which both leads to large economical losses. UHT milk was inoculated with four strains of S.aureus and then incubated at 37oC. Milk was sampled at six different time points (0, 0.5, 1, 2, 4, and 6 h). Samples were stored at -200C until analysis for protein separation by capillary electrophoresis (CE). CE was run for two strains (333 and 485) and electropherograms were obtained. Due to the quality of electropherograms only strain 485 was further evaluated for protein quantification. The level of milk proteins (caseins and whey proteins) was estimated for each sample by quantification of peak area. Data were statistically analysed using SAS ANOVA procedures. The lowest pH value of inoculated milk was 6.2, while pH of non-inoculated milk remained constant and was 6.7. Bacterial growth in log phase reached levels of 8x10 8 and 8.7x10 8 colony forming units for strain 333 and 485, respectively. The overall casein content was reduced by up to 21% due to S. aureus. SLU/Dept. of Animal Nutrition and Management (until 231231) 2012 H2 eng https://stud.epsilon.slu.se/6351/
spellingShingle milk
protein
proteolysis
Crnadak, Ninoslava
Proteolysis in UHT milk due to Staphylococcus aureus
title Proteolysis in UHT milk due to Staphylococcus aureus
title_full Proteolysis in UHT milk due to Staphylococcus aureus
title_fullStr Proteolysis in UHT milk due to Staphylococcus aureus
title_full_unstemmed Proteolysis in UHT milk due to Staphylococcus aureus
title_short Proteolysis in UHT milk due to Staphylococcus aureus
title_sort proteolysis in uht milk due to staphylococcus aureus
topic milk
protein
proteolysis