# Commercial pea protein ingredients: a multiscale investigation of high-pressure homogenized emulsification and relation with physicochemical and interfacial properties

## TL;DR

This study examines how different commercial pea proteins behave in food emulsions, revealing how their properties affect droplet size and stability.

## Contribution

The study provides new insights into how pea proteins function as emulsifiers, linking their physicochemical properties to emulsion stability.

## Key findings

- High-pressure homogenization produced emulsions with varying droplet sizes (1.1–2.7 μm, 5.8 μm, and >10 μm) depending on pea protein properties.
- Oil droplet size correlated with soluble protein content and stability was mainly governed by electrostatic repulsion.
- Three pea protein isolates are suitable for beverages and one for dressings based on emulsion stability.

## Abstract

Utilization of commercial pea protein (PP) in food emulsions largely depends on empirical experience due to insufficient knowledge. Emulsions made of seven commercial PP ingredients by high-pressure homogenization (HPH) were studied and uncovered their relationship with physicochemical and interfacial properties of homogenized PP. Results showed that HPH produced PP supernatants of varying size and composition, leading to differences in interfacial adsorption of emulsions. Four emulsions had very small droplets (1.1–2.7 μm), in contrast to one with medium sized droplets (5.8 μm) and two with large droplets (> 10 μm). The oil droplet size was highly correlated with the protein content and size in the soluble phase, suggesting that emulsification was mainly driven by soluble proteins after homogenization. Moreover, small droplet size was not a prerequisite to flocculation and coalescence stability. During storage, emulsions showed different mechanisms of destabilization. Overall, these results provided an accurate assessment of commercial PPs as emulsifiers, aiding the development of predictive models.

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•Interfacial and emulsifying properties of 7 commercial pea proteins vary considerably.•High soluble protein content after homogenization correlated with small oil droplets.•Mainly high electrostatic repulsion governs storage stability.•Stabilization mechanism is explained by interfacial composition and properties.•Three isolates would work for beverages and one isolate for dressing.

Interfacial and emulsifying properties of 7 commercial pea proteins vary considerably.

High soluble protein content after homogenization correlated with small oil droplets.

Mainly high electrostatic repulsion governs storage stability.

Stabilization mechanism is explained by interfacial composition and properties.

Three isolates would work for beverages and one isolate for dressing.