Casein–casein interactions in the presence of dairy associated carbohydrates analysed using surface plasmon resonance

Cristian De Gobba, Marie Sofie Møller, Valentin Rauh, Birte Svensson, Marianne N. Lund*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Ultrahigh temperature (UHT) processed and lactose-free milk are for export to Eastern markets. Free galactose and glucose in lactose-free milk increase occurrence of Maillard products and hence lower milk quality. Notably, enzymatic conversion of galactose into galacto-oligosaccharides (GOS) mitigates such undesirable reactions. As little is known about the effect of GOS on caseins, interactions between caseins in presence or absence of GOS or lactose were assessed by surface plasmon resonance analysis. Based on steady state binding constants (KD) soluble aS-casein showed one order of magnitude lower affinity than soluble b-casein and k-casein for chip-immobilised aS-and β-casein. By contrast, aS-casein had higher affinity for immobilised k-casein, followed by b- and k-casein. The interaction between the caseins did not obey a 1:1 binding model and it was not possible to calculate a precise stoichiometry. Importantly, lactose and GOS exerted very modest or no effect on the various interaction between the caseins.
Original languageEnglish
Article number104686
JournalInternational Dairy Journal
Volume105
Number of pages4
ISSN0958-6946
DOIs
Publication statusPublished - 2020

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