Effect of ultrasound treatment on dehydration kinetics and physicochemical, microbiological, structural and rehydration characteristics of tilapia

Abstract

The effect of ultrasound for 15 and 30 min (40 kHz, 130 W, 10% salt solution, 25°C) on dehydration kinetics and physicochemical, microbiological, structural and rehydration characteristics of tilapia cubes dehydrated at 35°C was evaluated. The ultrasound treatments decreased dehydration time in the range of 8.7–19.2%, in comparison with the control treatments (15 and 30 min, 10% salt solution, 25°C). Of the Wang and Singh, Lewis, Modified Page and Page models, the last one was the one that better described the dehydration kinetics. The ultrasound significantly (p < .05) increased the ash content and significantly (p < .05) decreased the aw of the dehydrated tilapia cubes but did not have an effect on the microbiological characteristics. In addition, the tilapia cubes treated with ultrasound presented porous structures with large and irregular cavities, which increased the amount of moisture absorbed in the rehydration, in comparison with the control treatments.

Keywords

• tilapia cubes
• dehydration
• ultrasound
• physicochemical characteristics
• rehydration