Jump to main content
Jump to site search
SCHEDULED MAINTENANCE Close the message box

Maintenance work is planned for Monday 16 August 2021 from 07:00 to 23:59 (BST).

Website performance may be temporarily affected and you may not be able to access some PDFs or images. If this does happen, refreshing your web browser should resolve the issue. We apologise for any inconvenience this might cause and thank you for your patience.


Issue 3, 2009

Emulsification alters simulated gastrointestinal proteolysis of β-casein and β-lactoglobulin

Author affiliations

Abstract

We have studied the effect of the adsorption of milk proteins at the oil-water interface on their digestibility in simulated gastrointestinal environment. The investigations aimed to characterize how both the breakdown of the adsorbed proteins and the interactions with physiological surfactants, phosphatidylcholine (PC) and bile salts (BS), influence structural transformations of model, protein-stabilized food emulsions in the gastrointestinal track.

Proteolysis of two contrasting proteins, β-casein (β-Cas) and β-lactoglobulin (β-Lg), was compared between the protein presented in solution or in emulsion, after adsorption at the oil-water interface. Digestion of β-Cas was faster when presented as an emulsion and led to the persistence of a 6 kD peptide not seen when the protein was presented in solution. Adsorption gave rise to a pepsin-susceptible form of β-Lg. Complex interactions were observed with PC introduced to the system in the vesicular form. Measurements of interfacial tension revealed that PC displaced the proteins from the oil droplets after only 30 s for β-Lg and 12 min for β-Cas, so that the gastric digestion largely took place in solution. Pepsinolysis of adsorbed β-Cas played a dominant role in emulsion destabilization. In contrast, collapse of β-Lg-stabilized emulsion under gastric conditions was mainly dependent on protein-PC interactions. β-Lg was significantly protected through simulated duodenal digestion as a result of a complex formed with the PC. In the absence of PC, the proteins were completely broken down after duodenal digestion, during which the duodenal surfactants, BS, displaced any remaining protein from the interface and governed the final structure of emulsion.

Graphical abstract: Emulsification alters simulated gastrointestinal proteolysis of β-casein and β-lactoglobulin

Article information


Submitted
01 Jul 2008
Accepted
10 Sep 2008
First published
28 Oct 2008

Soft Matter, 2009,5, 538-550
Article type
Paper

Emulsification alters simulated gastrointestinal proteolysis of β-casein and β-lactoglobulin

A. Macierzanka, A. I. Sancho, E. N. C. Mills, N. M. Rigby and A. R. Mackie, Soft Matter, 2009, 5, 538 DOI: 10.1039/B811233A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.


Social activity

Search articles by author

Spotlight

Advertisements