Interfacial and Emulsifying Properties of Quinoa Protein Concentrates

Most protein concentrates used by the food industry are derived from soybean or wheat, but a pseudocereal like quinoa is gaining interest worldwide. The aim of this study is the characterization of the emulsification properties of two quinoa protein concentrates obtained through alkaline extraction (pH 9 (Q9) and 11 (Q11)), followed by precipitation at an acidic pH value. Interfacial rheological measurements point out that Q11 form stronger protein films adsorbed on the interface, which finally results in emulsions with smaller droplet sizes. However, Q9 shows greater interfacial activity due to its more compact structure which results in a lower interfacial tension. An increase in the quinoa content in the emulsion formulation is paired with a reduction in the droplet size diameter as well as a greater stability during quiescent storage. These results prove the feasibility of using a quinoa concentrate as an ingredient in commercial food emulsions.