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Changes in proteins, physical stability and structure in directly heated UHT milk during storage at different temperatures

Malmgren, Bozena LU ; Ardö, Ylva; Langton, Maud; Altskär, Annika; Bremer, Maria G E G; Dejmek, Petr LU and Paulsson, Marie LU (2017) In International Dairy Journal 71. p.60-75
Abstract

Changes occurring in directly heated UHT milk were studied during storage at 5, 22, 30 and 40 °C. Industrially produced UHT milk samples were analysed for changes in enzymatic activity, protein modification, destabilisation of casein micelles and relocation of milk proteins in relation to sedimentation and gel formation. Sedimentation occurred at all temperatures, and the protein composition of the sediments reflected the composition of its liquid phase; however, there was no α-lactalbumin, β-lactoglobulin or κ-casein present in sediments. Tendrils composed of β-lactoglobulin and κ-casein were seen on casein micelles after UHT treatment and grew in length prior to gelation. High degrees of lactosylation of proteins and peptides were... (More)

Changes occurring in directly heated UHT milk were studied during storage at 5, 22, 30 and 40 °C. Industrially produced UHT milk samples were analysed for changes in enzymatic activity, protein modification, destabilisation of casein micelles and relocation of milk proteins in relation to sedimentation and gel formation. Sedimentation occurred at all temperatures, and the protein composition of the sediments reflected the composition of its liquid phase; however, there was no α-lactalbumin, β-lactoglobulin or κ-casein present in sediments. Tendrils composed of β-lactoglobulin and κ-casein were seen on casein micelles after UHT treatment and grew in length prior to gelation. High degrees of lactosylation of proteins and peptides were clearly correlated with the absence of gelation and long tendrils. Gelled samples showed complete hydrolysis of intact β-casein, and limited lactosylation of β-lactoglobulin and κ-casein.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
International Dairy Journal
volume
71
pages
16 pages
publisher
Elsevier
external identifiers
  • scopus:85016613718
  • wos:000401380100008
ISSN
0958-6946
DOI
10.1016/j.idairyj.2017.03.002
language
English
LU publication?
yes
id
086f1a6b-7124-43ea-a6f6-a10d1baa9156
date added to LUP
2017-04-11 08:20:27
date last changed
2018-04-08 04:55:46
@article{086f1a6b-7124-43ea-a6f6-a10d1baa9156,
  abstract     = {<p>Changes occurring in directly heated UHT milk were studied during storage at 5, 22, 30 and 40 °C. Industrially produced UHT milk samples were analysed for changes in enzymatic activity, protein modification, destabilisation of casein micelles and relocation of milk proteins in relation to sedimentation and gel formation. Sedimentation occurred at all temperatures, and the protein composition of the sediments reflected the composition of its liquid phase; however, there was no α-lactalbumin, β-lactoglobulin or κ-casein present in sediments. Tendrils composed of β-lactoglobulin and κ-casein were seen on casein micelles after UHT treatment and grew in length prior to gelation. High degrees of lactosylation of proteins and peptides were clearly correlated with the absence of gelation and long tendrils. Gelled samples showed complete hydrolysis of intact β-casein, and limited lactosylation of β-lactoglobulin and κ-casein.</p>},
  author       = {Malmgren, Bozena and Ardö, Ylva and Langton, Maud and Altskär, Annika and Bremer, Maria G E G and Dejmek, Petr and Paulsson, Marie},
  issn         = {0958-6946},
  language     = {eng},
  month        = {08},
  pages        = {60--75},
  publisher    = {Elsevier},
  series       = {International Dairy Journal},
  title        = {Changes in proteins, physical stability and structure in directly heated UHT milk during storage at different temperatures},
  url          = {http://dx.doi.org/10.1016/j.idairyj.2017.03.002},
  volume       = {71},
  year         = {2017},
}