The Effect of Ultrasonic Pre-Treatment on the Temperature Controlled Infrared Drying of Loligo vulgaris and Comparison with the Microwave Drying

Abstract

In this study the effect of ultrasonic pre-treatment (US) on the thin-layer infrared (IR) drying kinetics and modelling of Loligo vulgaris (Squid) were studied and obtained data were compared with the microwave drying (MW). In each three methods, effective moisture diffusivities (D-eff) and activation energies (E-a) were determined. According to the drying curves of Loligo vulgaris the highest drying times were found in IR and the lowest drying times were found in MW methods. Therefore, ultrasonic pre-treatment decreased the drying times. Drying takes place in the falling-rate period generally. Midilli & Kucuk model best fit the experimental data for each method with the coefficient of determination (R-2) values higher than 0.995. Highest D-eff values were found in MW method and calculated between 1.25x10(-8) - 5.62x10(-8) m(2)/s, and the lowest D-eff values were found in IR method and calculated between 6.57 x 10(-10) - 1.35 x 10(-9) m(2)/s. Moreover, E-a values were found 35.20 and 37.12 kJ/mol for IR and US-IR, and 35.43 for MW methods. Drying time, temperature and power levels lead to color changes.