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Review Articles

Whey proteins: targets of oxidation, or mediators of redox protection

ORCID Icon, ORCID Icon, ORCID Icon, , , ORCID Icon, ORCID Icon & ORCID Icon show all
Pages 1136-1152 | Received 04 Mar 2019, Accepted 06 Jun 2019, Published online: 12 Sep 2019
 

Abstract

Bovine whey proteins are highly valued dairy ingredients. This is primarily due to their amino acid content, digestibility, bioactivities and their processing characteristics. One of the reported bioactivities of whey proteins is antioxidant activity. Numerous dietary intervention trials with humans and animals indicate that consumption of whey products can modulate redox biomarkers to reduce oxidative stress. This bioactivity has in part been assigned to whey peptides using a range of biochemical or cellular assays in vitro. Superimposing whey peptide sequences from gastrointestinal samples, with whey peptides proven to be antioxidant in vitro, allows us to propose peptides from whey likely to exhibit antioxidant activity in the diet. However, whey proteins themselves are targets of oxidation during processing particularly when exposed to high thermal loads and/or extensive processing (e.g. infant formula manufacture). Oxidative damage of whey proteins can be selective with regard to the residues that are modified and are associated with the degree of protein unfolding, with α-Lactalbumin more susceptible than β-Lactoglobulin. Such oxidative damage may have adverse effects on human health. This review summarises how whey proteins can modulate cellular redox pathways and conversely how whey proteins can be oxidised during processing. Given the extensive processing steps that whey proteins are often subjected to, we conclude that oxidation during processing is likely to compromise the positive health attributes associated with whey proteins.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the European Cooperation in Science and Technology (COST) under Grant COST Action CA16112-NutRedOx Network, the Novo Nordisk Foundation [grant NNF13OC0004294 to MJD], Science Foundation Ireland [grant 16/RC/3835 to LG], Irish Department of Agriculture, Food and Fisheries [grant FIRM 15F604 to MC] and Marie Skłodowska-Curie-Career FIT by Enterprise Ireland and European Union’s Horizon 2020 [grant MF2018-0151 to EA].