Partitioning Behavior and Interfacial Activity of Phenolic Acid Derivatives and their Impact on \u03b2-Lactoglobulin at the Oil-Water Interface

Alina Bock,Stephan Drusch,Ulrike Steinhäuser

doi:10.1007/s11483-020-09663-7

Alina Bock, Stephan Drusch + Show 1 more

Open Access

https://doi.org/10.1007/s11483-020-09663-7

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Abstract

Proteins are able to stabilize dispersed food systems due to their amphiphilic nature, acting as emulsifiers. Their interfacial properties can be influenced by different methods, including the formation of protein-phenol nanocomplexes. In this study, the interfacial behavior of phenolic compounds and protein-phenol nanocomplexes was first characterized according to the oil-water partitioning behavior of phenolic acid derivatives according to their molecular structure and its impact on interfacial tension. The influence of the phenolic compounds on protein film formation and its properties by dilatational rheology was then evaluated. The most phenolic acid derivatives are predominantly present in the aqueous phase. Despite their hydrophobic benzene body, weak interfacial activity was observed depending on their chemical structure. This result supports possible protein-phenol nanocomplex formation in the aqueous phase and possible interactions at the oil-water interface. Protein-phenol nanocomplexes showed decreased interfacial adsorption properties and decreased viscoelastic interfacial behavior, depending on the expansion of the delocalized π-electrons in the phenol.

Highlights

The stability of a dispersed system depends heavily on phenomena occurring at its interface
The addition of a second hydroxyl group already results in a higher partitioning of caffeic acid into the aqueous phase due to an increasing number of hydrogen bonds with water molecules
Phenolic acid derivatives were analyzed for their oil-water partitioning behavior, their potential to reduce the interfacial tension, and their impact on interfacial behavior of β-lactoglobulin

Summary

Introduction

The stability of a dispersed system depends heavily on phenomena occurring at its interface. Food Biophysics (2021) 16:191–202 customize functionality, for example to achieve protection and targeted delivery of bioactive ingredients [7,8,9]. This so-called “interfacial engineering” first aimed at improving the oxidative stability of nutritional oils through the incorporation of hydrolyzed proteins and phenolics in the interfacial film [10,11,12]. Different studies have shown that at low pH values, the phenolic hydroxyl groups are protonated and non-covalent hydrophobic interactions with proteins may occur and be stabilized by hydrogen bonds [19,20,21,22,23]. Previous studies on β-lactoglobulin and phenolic compound (curcumin) (reference) showed that hydrogen bonds, π-stacking, and other π-interactions like π-alkyl, π-anion, and π-sigma – as a kind of hydrophobic interactions – are the main forces for this proteinphenol bonding [29]

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