Total proteolysis in bovine raw bulk milk of Northern Sweden
Proteases are enzymes that catalyze protein breakdown. The major indigenous protease is plasmin, that together with proteases originating from somatic cells and bacteria, accounts for most of the proteolytic activity in bovine milk. In many dairy products, the key characteristics depends on the conc...
Main Author: | |
---|---|
Format: | Text |
Language: | Swedish English |
Published: |
2020
|
Subjects: | |
Online Access: | https://stud.epsilon.slu.se/16358/4/toss_ekmyr_e_210105%20%281%29.pdf |
id |
ftsluppsalast:oai:stud.epsilon.slu.se:16358 |
---|---|
record_format |
openpolar |
spelling |
ftsluppsalast:oai:stud.epsilon.slu.se:16358 2023-05-15T17:44:31+02:00 Total proteolysis in bovine raw bulk milk of Northern Sweden Toss Ekmyr, Elina 2020-12-18 application/pdf https://stud.epsilon.slu.se/16358/4/toss_ekmyr_e_210105%20%281%29.pdf sv eng swe eng https://stud.epsilon.slu.se/16358/ urn:nbn:se:slu:epsilon-s-16358 https://stud.epsilon.slu.se/16358/4/toss_ekmyr_e_210105%20%281%29.pdf Toss Ekmyr, Elina, 2020. Total proteolysis in bovine raw bulk milk of Northern Sweden. Second cycle, A2E. Uppsala: (NL, NJ) > Department of Molecular Sciences <https://stud.epsilon.slu.se/view/divisions/OID-425.html> Food composition Second cycle, A2E NonPeerReviewed 2020 ftsluppsalast 2022-09-10T18:12:52Z Proteases are enzymes that catalyze protein breakdown. The major indigenous protease is plasmin, that together with proteases originating from somatic cells and bacteria, accounts for most of the proteolytic activity in bovine milk. In many dairy products, the key characteristics depends on the concentration and composition of the milk proteins. It has been seen in other studies that environmental and production parameters can influence the level and activity of proteases. The objective of this study was to measure the level of total proteolysis in raw bulk milk of Northern Sweden and investigate if there are correlations between the total proteolysis and any of the parameters: plasmin, somatic cell counts, total bacteria number, milk pH, total milk protein, breed, milking system, production system (tied or loose house), number of animals or different seasons. The total proteolysis, that was measured as the level of peptides in the milk samples, was significantly correlated to the milk protein content (P<0.001) and the milk pH value (P<0.01) in a Pearson correlation. The same connection was seen when one variable at a time was compared in a regression; there was a correlation between proteolysis and milk pH (P<0.05), as well as milk protein content (P<0.001). In addition, there were significant differences between the breeds, where Jersey cows had 25.7 % higher proteolytic activity compared to the other breeds. There was also a difference between the housing systems, where milk from tied cows had 10.6 % higher proteolysis, compared to milk from loose housed cows (P=0.002). However, when all variables were included in a multivariable regression model, no variable was significantly correlated to total proteolysis. Nevertheless, some interesting trends were observed. The !-value was negative for all the breeds (SRB, SLB, Mountain Breed and farms with both SRB and SLB), when they were compared to the Jersey breed. Also, a trend towards a correlation between plasmin and proteolysis, seen in the single ... Text Northern Sweden Swedish University of Agricultural Sciences: Epsilon Archive for Student Projects |
institution |
Open Polar |
collection |
Swedish University of Agricultural Sciences: Epsilon Archive for Student Projects |
op_collection_id |
ftsluppsalast |
language |
Swedish English |
topic |
Food composition |
spellingShingle |
Food composition Toss Ekmyr, Elina Total proteolysis in bovine raw bulk milk of Northern Sweden |
topic_facet |
Food composition |
description |
Proteases are enzymes that catalyze protein breakdown. The major indigenous protease is plasmin, that together with proteases originating from somatic cells and bacteria, accounts for most of the proteolytic activity in bovine milk. In many dairy products, the key characteristics depends on the concentration and composition of the milk proteins. It has been seen in other studies that environmental and production parameters can influence the level and activity of proteases. The objective of this study was to measure the level of total proteolysis in raw bulk milk of Northern Sweden and investigate if there are correlations between the total proteolysis and any of the parameters: plasmin, somatic cell counts, total bacteria number, milk pH, total milk protein, breed, milking system, production system (tied or loose house), number of animals or different seasons. The total proteolysis, that was measured as the level of peptides in the milk samples, was significantly correlated to the milk protein content (P<0.001) and the milk pH value (P<0.01) in a Pearson correlation. The same connection was seen when one variable at a time was compared in a regression; there was a correlation between proteolysis and milk pH (P<0.05), as well as milk protein content (P<0.001). In addition, there were significant differences between the breeds, where Jersey cows had 25.7 % higher proteolytic activity compared to the other breeds. There was also a difference between the housing systems, where milk from tied cows had 10.6 % higher proteolysis, compared to milk from loose housed cows (P=0.002). However, when all variables were included in a multivariable regression model, no variable was significantly correlated to total proteolysis. Nevertheless, some interesting trends were observed. The !-value was negative for all the breeds (SRB, SLB, Mountain Breed and farms with both SRB and SLB), when they were compared to the Jersey breed. Also, a trend towards a correlation between plasmin and proteolysis, seen in the single ... |
format |
Text |
author |
Toss Ekmyr, Elina |
author_facet |
Toss Ekmyr, Elina |
author_sort |
Toss Ekmyr, Elina |
title |
Total proteolysis in bovine raw bulk milk of Northern Sweden |
title_short |
Total proteolysis in bovine raw bulk milk of Northern Sweden |
title_full |
Total proteolysis in bovine raw bulk milk of Northern Sweden |
title_fullStr |
Total proteolysis in bovine raw bulk milk of Northern Sweden |
title_full_unstemmed |
Total proteolysis in bovine raw bulk milk of Northern Sweden |
title_sort |
total proteolysis in bovine raw bulk milk of northern sweden |
publishDate |
2020 |
url |
https://stud.epsilon.slu.se/16358/4/toss_ekmyr_e_210105%20%281%29.pdf |
genre |
Northern Sweden |
genre_facet |
Northern Sweden |
op_relation |
https://stud.epsilon.slu.se/16358/ urn:nbn:se:slu:epsilon-s-16358 https://stud.epsilon.slu.se/16358/4/toss_ekmyr_e_210105%20%281%29.pdf Toss Ekmyr, Elina, 2020. Total proteolysis in bovine raw bulk milk of Northern Sweden. Second cycle, A2E. Uppsala: (NL, NJ) > Department of Molecular Sciences <https://stud.epsilon.slu.se/view/divisions/OID-425.html> |
_version_ |
1766146756153704448 |