Physicochemical Properties of Soy Protein Concentrate Treated with Ultrasound at Various Amplitudes

Authors : Gülçin YILDIZ

Pages : 133-139

Doi:10.21597/jist.436852

View : 11 | Download : 8

Publication Date : 2018-12-30

Article Type : Research Paper

Abstract :This research was conducted to investigate the influence of ultrasound amplitude on the physicochemical properties of soy protein concentrate. Soy protein concentrates (SPC, Acron SM) were treated with a frequency of 20 kHz ultrasound and three different amplitudes of 50, 80, and 100% for 5 min. Untreated and ultrasound-treated soy protein concentrate samples were evaluated in terms of recovery of soluble protein, particle size, surface hydrophobicity, free sulfhydryl groups, turbidity and microstructure. The environmental scanning electron microscope images of the treated and untreated soy protein concentrate samples were taken in order to analyze the microstructure of the samples. The findings showed that the ultrasound treatment have a significant effect on all physicochemical characteristics (p<0.05). All ultrasound treated samples showed significantly higher solubility compared to the untreated soy protein concentrates. In addition, the highest protein solubility was determined for the samples treated with 100% amplitude. Ultrasound treatment reduced the size of all proteins. The sample which has the highest solubility also showed the lowest particle size compared to the others. Moreover, ultrasound treated (100% amplitude) soy protein concentrate was resulted with highest surface hydrophobicity and free sulfhydryl groups. Microscope images of the soy protein concentrates showed a spherical morphology with particle diameters which closely corresponding to the results obtained by dynamic light scattering. It was clearly seen that increasing ultrasound amplitude enhance the functionality of soy protein concentrates.
Keywords : Ultrasound amplitude, soy protein concentrate, particle size, protein solubility, surface hydrophobicity, free sulfhydryl group