# Understanding Stabilization of Oil-in-Water Emulsions with Pea Protein—Studies of Structure and Properties

## TL;DR

This study explores how pea protein stabilizes oil-in-water emulsions, finding that a thick protein layer and high viscosity help prevent droplet separation.

## Contribution

The study identifies a specific pea protein concentration and oil range that ensures emulsion stability and reveals structural insights through X-ray scattering.

## Key findings

- A pea protein concentration of at least 5% w/v and oil content of 30–50% v/v ensures emulsion stability.
- X-ray scattering shows a dense protein layer at the interface and hydrated protein in the continuous phase.
- Emulsions exhibit shear-thinning behavior and similar stability across acidic to neutral pH ranges.

## Abstract

This study investigates the stability and structure of
oil-in-water
emulsions stabilized by pea protein. Of the wide range of emulsion
compositions explored, a region of stability at a minimum of 5% w/v
pea protein and 30–50% v/v oil was determined. This pea protein
concentration is more than what is needed to form a layer covering
the interface. X-ray scattering revealed a thick, dense protein layer
at the interface as well as hydrated protein dispersed in the continuous
phase. Shear-thinning behavior was observed, and the high viscosity
in combination with the thick protein layer at the interface creates
a good stability against creaming and coalescence. Emulsions in a
pH range from acidic to neutral were studied, and the overall stability
was observed to be broadly similar independently of pH. Size measurements
revealed polydisperse protein particles. The emulsion droplets are
also very polydisperse. Apart from understanding pea protein-stabilized
emulsions in particular, insights are gained about protein stabilization
in general. Knowledge of the location and the role of the different
components in the pea protein material suggests that properties such
as viscosity and stability can be tailored for various applications,
including food and nutraceutical products.