Interfacial behavior of vegetable protein isolates at sunflower oil/water interface

• Published in: Colloids and surfaces, B, Biointerfaces B, Biointerfaces, 2023-01, Vol.221, p.113035-113035, Article 113035
• Main Authors: Mileti, Olga, Baldino, Noemi, Lupi, Francesca Romana, Gabriele, Domenico
• Format: Article
• Language: English
• Subjects: adsorption; animals; brown rice; Brown rice protein isolate; consumer demand; ethics; food industry; hemp; Hemp protein isolate; Interfacial rheology; Interfacial tension; magnetism; rice protein; soy protein; Soy protein isolate; stress relaxation; sunflower oil; surface tension; vegetable protein; Vegetable proteins; viscoelasticity
• ISSN: 0927-7765; 1873-4367
• DOI: 10.1016/j.colsurfb.2022.113035

Proteins are widely used in the formation and stabilization of multiphase systems, thanks to their ability to adsorb at the interface reducing the interfacial tension and promoting the formation of viscoelastic layers. Owing to the growing consumer demand, the food industry is moving toward the growing use of plant-based proteins, suitable for consumers who do not eat products of animal origin, for either ethical or health reasons. Nevertheless, the scientific literature lacks information on the surface activity and emulsifying ability of these proteins. In this work, the interfacial properties of soy, hemp and brown rice isolate proteins were investigated at the interface with commercial sunflower oil (O/W) to evaluate their characteristics in view of potential uses in food applications such as emulsions, sauces, dressing, topping and soft foods. Dilatational and shear kinematic, with pendant drop and magnetic rod techniques, respectively, were used. The dilatational analysis was performed in static and dynamic conditions, to obtain the equilibrium adsorption isotherms and the rheological parameters of the interfacial layers under both oscillation and stress relaxation. The interfaces were studied in shear conditions with small amplitude oscillations and creep tests. The obtained results evidenced that all tested proteins are able to build a strong viscoelastic layer with properties comparable to those of animal proteins. Brown rice protein seems particularly effective in reducing the interfacial tension even if shear tests evidence that the interface is weaker than that obtained using hemp or soy protein. Hemp protein seems very promising for potential practical uses yielding intermediate interfacial tensions and strong viscoelastic layers. [Display omitted] •Interfacial rheology of vegetable proteins at the sunflower oil/air interface was investigated.•Brown rice protein isolate seems particularly effective in reducing the interfacial tension and promoting emulsion formation.•Hemp protein isolate seems promising for potential practical uses because of its ability to bear destabilization phenomena.•Soy protein isolate shows an intermediate interfacial behavior between brown rice and hemp protein isolate.