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

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

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

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

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