Investigation of Numerical Model of the Thawing Process of Egg White by Different Ultrasound Cycles

In this study, different ultrasound cycles (0, 25, 50 and 75%) were separately applied to optimize the thawing process of frozen egg whites. Frozen egg white samples with temperatures of -30.0 ± 0.5 °C were placed in an ultrasonic bath at 30 °C with ultrasound frequency of 18 kHz to record temperature changes. The experimental data were modeled using OpenFOAM software coupled with the Dakota tool, by a numerical inverse method. The outputs of the inverse modeling were involved fitted heat transfer coefficient and numerical temperature data. The results showed that the use of ultrasonic waves increased the heat transfer coefficient and reduced the thawing process duration. Increasing the sonication duty cycle increased the heat transfer coefficient and further reduced the thawing time, so that the heat transfer coefficient increased from 105.2 to 128.8 W/m2K in 50% cycle without using ultrasound, and to 126.7 W/m2K in 75% cycle and also process time was reduced from 3280 s in absent of ultrasound to 2473 (s) in 75% cycle with the use of ultrasound. Comparison of the model data with the experimental data indicated that there was a high agreement between them (R2>0.97), which can be used in other similar foods. The inverse modeling method can be widely used to determine heat transfer coefficient by fitting experimental data with numerical ones.