Emulsifying properties; Pea protein isolate; Protein structure; Droplets sizes; Emulsifying activity; Emulsifying property; Emulsifying stabilities; Pea protein isolates; Performance; PH-dependent; Proteins structures; Structure-function relationship; Surface hydrophobicity; Structural Biology; Biochemistry; Molecular Biology
Abstract :
[en] This study investigated the relationship between pea protein isolates (PPI) emulsifying properties and their structural, interfacial, and physicochemical characteristics at various pH values (native pH, 7, 5, and 3). Emulsion characteristics including emulsifying activity and stability, droplet size, flocculation index (FI) and coalescence index (CI) were examined. Additionally, physicochemical properties such as solubility, zeta potential, surface hydrophobicity, interfacial protein adsorption and protein conformation were analyzed. Results revealed significant pH-dependent variations in emulsifying performance. The poorest emulsifying performance was observed at pH 5, with the largest droplet size (28.84 μm) and highest CI (38.94 %). Optimal emulsifying properties were noticed at native pH, with the smallest droplet size (7.73 μm) and lowest CI (4.69). At pH 3, good emulsifying ability with the highest physical stability (5.43) were observed, associated with increased surface hydrophobicity and the presence of some aggregates contributing to the formation of cohesive interfacial film. Structural elements, particularly β-sheets and random coils, were positively correlated with emulsifying activity and stability, while β-turns had a negative impact. These findings provide insights into the pH-dependent emulsifying behavior of PPI, highlighting the complex relationship between protein structure and functionality, enabling the optimization of the use of PPI as an emulsifier in food applications.
Disciplines :
Food science
Author, co-author :
Othmeni, Ines ; Université de Liège - ULiège > TERRA Research Centre
Blecker, Christophe ; Université de Liège - ULiège > TERRA Research Centre > Technologie Alimentaire (TA)
This research was funded by Cosucra Groupe Warcoing S.A. (Warcoing, Belgium) and the Walloon Region (grant number 8224).The authors wish to express their gratitude to the Walloon Region for their support (grant 8224). They also extend their thanks to Jonathan Willocq and Lionel Dumoulin from Cosucra Groupe Warcoing for their guidance and assistance throughout the project. The authors gratefully acknowledge Marjorie Servais (Teaching and Research Center, Gembloux Agro-BioTech, Belgium) for the support regarding the rheological analysis.This research was funded by Cosucra Groupe Warcoing S.A. (Warcoing, Belgium) and the Walloon Region (grant number 8224 ).
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