Effect of ultrasound treatment on the composition and emulsifying properties of quinoa okara

Abstract

High-intensity ultrasound (HIUS) treatment is a physical method utilised to modify and improve some technologically important compounds (such as protein, fibres) that serves as an environment-friendly process. In this regard, the effect of HIUS on the composition and emulsifying properties of quinoa okara fractions was analysed. Dispersions (1:10) of ground quinoa grains alkalinised to pH 9.0 were treated by high-intensity ultrasound. Quinoa okara and sonicated quinoa okara (SQOK) exhibited a similar extraction yield (60%), although SQOK showed a three-fold increase in protein content. Scanning electron microscopy showed that HIUS reduced the particle size of okara molecular structures. Analysis of O/W emulsions formulated with the okara samples demonstrated that the SQOK had a smaller droplet size and increased the stability of the system against the destabilisation processes of creaming and coalescence. The quinoa okara optimised with the application of the clean ultrasound technology allows adding value to a by-product with potential applications as a food emulsifier. Quinoa okara could be used as an innovative additive for application in the emerging plant-based food market.