Kinetics of pepsin-induced hydrolysis and the coagulation of milk proteins

Simple item page
dc.citation.issue2
dc.citation.volume105
dc.contributor.authorYang M
dc.contributor.authorYe A
dc.contributor.authorYang Z
dc.contributor.authorEverett DW
dc.contributor.authorGilbert EP
dc.contributor.authorSingh H
dc.coverage.spatialUnited States
dc.date.accessioned2023-10-31T23:59:32Z
dc.date.accessioned2023-11-03T04:55:12Z
dc.date.available2022-01-05
dc.date.available2023-10-31T23:59:32Z
dc.date.available2023-11-03T04:55:12Z
dc.date.issued2022-02
dc.description.abstractHydrolysis-induced coagulation of casein micelles by pepsin occurs during the digestion of milk. In this study, the effect of pH (6.7–5.3) and pepsin concentration (0.110–2.75 U/mL) on the hydrolysis of κ-casein and the coagulation of the casein micelles in bovine skim milk was investigated at 37°C using reverse-phase HPLC, oscillatory rheology, and confocal laser scanning microscopy. The hydrolysis of κ-casein followed a combined kinetic model of first-order hydrolysis and putative pepsin denaturation. The hydrolysis rate increased with increasing pepsin concentration at a given pH, was pH dependent, and reached a maximum at pH ~6.0. Both the increase in pepsin concentration and decrease in pH resulted in a shorter coagulation time. The extent of κ-casein hydrolysis required for coagulation was independent of the pepsin concentration at a given pH and, because of the lower electrostatic repulsion between para-casein micelles at lower pH, decreased markedly from ~73% to ~33% when pH decreased from 6.3 to 5.3. In addition, the rheological properties and the microstructures of the coagulum were markedly affected by the pH and the pepsin concentration. The knowledge obtained from this study provides further understanding on the mechanism of milk coagulation, occurring at the initial stage of transiting into gastric conditions with high pH and low pepsin concentration.
dc.description.confidentialfalse
dc.edition.editionFebruary 2022
dc.format.pagination990-1003
dc.identifier.author-urlhttps://www.ncbi.nlm.nih.gov/pubmed/34998540
dc.identifier.citationYang M, Ye A, Yang Z, Everett DW, Gilbert EP, Singh H. (2022). Kinetics of pepsin-induced hydrolysis and the coagulation of milk proteins.. J Dairy Sci. 105. 2. (pp. 990-1003).
dc.identifier.doi10.3168/jds.2021-21177
dc.identifier.eissn1525-3198
dc.identifier.elements-typejournal-article
dc.identifier.issn0022-0302
dc.identifier.piiS0022-0302(21)01108-5
dc.identifier.urihttps://mro.massey.ac.nz/handle/10179/69016
dc.languageeng
dc.publisherElsevier Inc and the Federation of Animal Science Societies on behalf of the American Dairy Science Association
dc.publisher.urihttps://www.sciencedirect.com/science/article/pii/S0022030221011085
dc.relation.isPartOfJ Dairy Sci
dc.rights(c) 2022 The Author/s
dc.rightsCC BY 4.0
dc.rights.urihttps://creativecommons.org/licenses/by/4.0/
dc.subjectenzymatic hydrolysis kinetics
dc.subjectmicrostructure
dc.subjectmilk coagulation
dc.subjectpepsin
dc.subjectrheology
dc.subjectAnimals
dc.subjectCaseins
dc.subjectCattle
dc.subjectHydrogen-Ion Concentration
dc.subjectHydrolysis
dc.subjectKinetics
dc.subjectMicelles
dc.subjectMilk Proteins
dc.subjectPepsin A
dc.subjectRheology
dc.titleKinetics of pepsin-induced hydrolysis and the coagulation of milk proteins
dc.typeJournal article
pubs.elements-id450258
pubs.organisational-groupOther
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Published version
Size:
6.19 MB
Format:
Adobe Portable Document Format
Description:
Download
Collections
Journal Articles