# Exploring whey and faba bean protein interactions at the oil-water interface: A combined drop tensiometry and microfluidicsstudy

## TL;DR

This study examines how whey and faba bean proteins interact at oil-water interfaces, using microfluidics and drop tensiometry to understand their effects on droplet stability and behavior.

## Contribution

The study introduces a combined microfluidics and drop tensiometry approach to analyze protein interactions at oil-water interfaces.

## Key findings

- Mixed protein systems showed smaller droplets with narrower size distributions.
- Droplet stability increased with higher WPI/FPI ratios.
- Antagonistic interactions reduced the elastic modulus and increased shape eccentricity.

## Abstract

The interfacial properties of model oil–water interfaces stabilized by faba bean protein isolate (FPI), whey protein isolate (WPI), and their mixtures were investigated. Two complementary techniques, microfluidics-based analysis and drop tensiometry were employed to study the impact of protein mixing on interfacial tension, adsorption kinetics, and droplet stability. A microfluidic platform was used for droplet generation and single droplet analysis, assessing the impact of protein blending on droplet size and shape eccentricity after droplet generation. Drop tensiometry complemented the microfluidics-based analysis by evaluating interfacial tension and viscoelastic properties of the various interfaces. The presence of FPI altered WPI interfaces; in mixed systems, antagonistic interactions between proteins resulted in a decreased elastic modulus and broadening of the shape eccentricity. Mixed systems resulted in smaller droplets with narrower size distributions and increased resistance to short-term coalescence with respect to emulsion droplets stabilized by FPI alone, and droplet stability increased proportionally with WPI/FPI ratio.

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•WPI and FPI interact at the oil-water interface, forming blends.•Microfluidics and interfacial tensiometry offer complementary insights, capturing interfacial behavior across timescales.•Mixed systems exhibited rapid adsorption due to surface-active FPI components.•Droplet size, distribution, shape eccentricity, and coalescence behavior were influenced by the WPI/FPI ratio.

WPI and FPI interact at the oil-water interface, forming blends.

Microfluidics and interfacial tensiometry offer complementary insights, capturing interfacial behavior across timescales.

Mixed systems exhibited rapid adsorption due to surface-active FPI components.

Droplet size, distribution, shape eccentricity, and coalescence behavior were influenced by the WPI/FPI ratio.