Abstract

Changes occurring in directly heated UHT milk were studied during storage at 5, 22, 30 and 40 degrees 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 a-lactalbumin, beta-lacto-globulin or kappa-casein present in sediments. Tendrils composed of beta-lactoglobulin and kappa-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 beta-casein, and limited lactosylation of beta-lactoglobulin and kappa-casein. (C) 2017 Published by Elsevier Ltd.

Published in

International Dairy Journal
2017, Volume: 71, pages: 60-75
Publisher: ELSEVIER SCI LTD

SLU Authors

• Langton, Maud

  • Department of Molecular Sciences, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Food Science


Publication identifier

DOI: https://doi.org/10.1016/j.idairyj.2017.03.002

Permanent link to this page (URI)

https://res.slu.se/id/publ/82890