Ultrasound treatment improved the emulsifying property of a protein concentrate obtained from giant squid

Abstract

In recent years, food technology researchers have focused on improving the functional properties of proteins; several technologies have been used for this purpose, ultrasound being one of the most promising technologies. For this reason, the effect of ultrasound (20 kHz; 20% and 40% amplitude; 30, 60, and 90 s) on emulsifying properties of proteins from giant squid (Dosidicus gigas) mantle was studied. Changes in particle size, zeta potential, rheological properties, and micrographs were obtained. Emulsion stability was monitored by determining the size of the droplets as well as changes in their viscosity over 15 days. Treatment with 40% amplitude for 90 s showed lower particle size, and they were consistent with the micrograph images. Protein solutions showed a pseudoplastic behavior, being considered as non-Newtonian fluid. After 15 days of storage, the untreated sample presented a Sauter diameter (3, 2) of 20.06 ± 0.17 µm, while samples treated with ultrasound showed values of 13.64 ± 0.15 µm. The apparent viscosity of emulsions decreased by the ultrasound effect. In this regard, the ultrasound treatment improved the physicochemical and emulsifying features of the squid proteins, showing that it can be a potential technology for industrial applications to improve the functional properties of jumbo squid proteins.