Drying of sardine muscles: Experimental and mathematical investigations

The aim of this work was to study the effect of air drying process on the dehydration kinetics of sardine muscles (Sardina pilchardus). Experimental drying kinetics were measured at five air temperatures (40, 50, 60, 70 and 80 °C), two relative humidity and at a constant air velocity of 1.5 m/s. The sardine drying kinetics were accelerated by increasing air temperature and were showed down when increasing air humidity. Moisture desorption isotherms of sardine muscles were determined at three temperatures (40, 50 and 70 °C) by using the static gravimetric method. The equilibrium moisture contents of sardine muscles were used to treat mathematically the experimental drying kinetics. Experimental drying kinetics and desorption isotherms of sardine muscles were described by using empiric models available in the literature. Eight models (GAB, BET, Henderson–Thompson, Modified Chung & Pfost, Modified Halsey, Oswin, Peleg and Adam & Shove models) were compared in order to describe the desorption isotherms. The Peleg model showed the best fitting of experimental data. For the drying kinetics, the Page model allowed a better fitting than the Newton and the Henderson and Pabis models. The Page model was thus used for simulating the drying kinetics of sardine muscles between 40 and 80 °C.