An investigation of the enzymatic cleavage of κ-casein in non-coagulating milk

Research output: Contribution to journalArticle

Abstract

Non-coagulating milk is unwanted in cheese production because it impairs chymosin-induced coagulation properties in bulk milk. Milk samples were analysed to investigate the coagulation process in non-coagulating milk for comparison with milk samples that have a high coagulation ability. This was done by measuring two peptides after chymosin cleavage, namely para-κ-casein and caseinomacropeptide, in all the milk samples using capillary electrophoresis. The results showed that cleavage of κ-casein into para-κ-casein and caseinomacropeptide occurred in both coagulation groups, suggesting that the aggregation stage is the cause of non-coagulating milk. Non-coagulating milk had lower content of para-κ-casein after chymosin addition compared with coagulating milk, which might be the result of a lower content of available κ-casein. Furthermore, this study indicates that there are different mechanisms that explain good coagulation ability and lack of coagulation ability of milk. The results can be useful in understanding the potential chemical mechanisms behind non-coagulating milk.

Details

Authors
Organisations
External organisations
  • Norwegian University of Life Sciences
  • Arla Foods
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Animal and Dairy Science
Original languageEnglish
Article number104754
JournalInternational Dairy Journal
Volume109
Publication statusPublished - 2020
Publication categoryResearch
Peer-reviewedYes