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Research article - Peer-reviewed, 2019

The Effect of Calcium, Citrate, and Urea on the Stability of Ultra-High Temperature Treated Milk: A Full Factorial Designed Study

Karlsson, Maria A.; Lundh, Ase; Innings, Fredrik; Hojer, Annika; Wikstrom, Malin; Langton, Maud

Abstract

The composition of raw milk is important for the stability of dairy products with a long shelf-life. Based on known historical changes in raw milk composition, the aim of this study was to get a better understanding of how possible future variations in milk composition may affect the stability of dairy products. The effects of elevated calcium, citrate, and urea levels on the stability of ultra-high temperature (UHT) treated milk stored for 52 weeks at 4, 20, 30, and 37 degrees C were investigated by a two-level full factorial designed study with fat separation, fat adhesion, sedimentation, color, pH, ethanol stability, and heat coagulation time as response variables. The results showed that elevated level of calcium lowered the pH, resulting in sedimentation and significantly decreased stability. Elevated level of citrate was associated with color, but the stability was not improved compared to the reference UHT milk. Elevated levels of urea or interaction terms had little effect on the stability of UHT milk. Storage conditions significantly affected the stability. In conclusion, to continue produce dairy products with high stability, the dairy industry should make sure the calcium content of raw milk is not too high and that storage of the final product is appropriate.

Keywords

UHT milk; interaction effects; calcium; citrate; urea; storage temperature; storage time; shelf-life

Published in

Foods
2019, volume: 8, number: 9, article number: 418

Authors' information

Karlsson, Maria
Swedish University of Agricultural Sciences, Department of Molecular Sciences
Swedish University of Agricultural Sciences, Department of Molecular Sciences
Innings, Fredrik
Tetra Pak Research & Development AB
Höjer, Annika
Norrmejerier Ek Förening
Wikström, Malin
Norrmejerier Ek Förening
Swedish University of Agricultural Sciences, Department of Molecular Sciences

UKÄ Subject classification

Food Engineering
Food Science
Animal and Dairy Science

Publication Identifiers

DOI: https://doi.org/10.3390/foods8090418

URI (permanent link to this page)

https://res.slu.se/id/publ/101595