Estabilização de emulsões concentradas de óleo de laranja com isolado proteico de ervilha

Abstract

The study of concentrated beverage emulsions (O/W) correlating their stability with their physicochemical properties is of great importance to reduce the empiric aspect that runs in the industry. The aim of this study is to evaluate several emulsion formulations analyzing two natural emulsifying agents, a pea protein isolate (PPI) and a nanocelulose, relating their properties with the achieved stabilities, as well as to perform the encapsulation of a vitamin (α-tocopherol), making the product a functional beverage. The nanocelulose showed poor emulsifying properties, being discarded later on the project. Analyses of interfacial film formation, surface and interfacial tension, electrokinetic potential, droplets diameter, rheological bulk properties and interfacial rheology were performed. A 2 3 full factorial design with 3 central points was carried out, in which the concentration of PPI in the emulsion (5% to 10%), the concentration of orange oil in the emulsion (20% to 40%) and the pH of the system (2.5 to 7) were varied. Emulsions with stability superior to 60 days were obtained with high levels of protein and oil. It was observed the formation of a viscoelastic tridimensional network in high viscosity emulsions and a high correlation between the stability and the zeta potential module. The encapsulation was successfully performed (>95%), without loss of the emulsion stability.