Estudo teórico e experimental da desidratação da tainha em secador alternativo e estufa comercial

The mullet is one of the most abundant fish in the Brazilian coast. Marine fish, such as mullet, is one of the food resources of better quality and abundance, thanks to its nutritional value, easy digestibility and balanced composition. However, much of the extracted fish is wasted due to their rapid deterioration occurring in less than 24 hours. To combat waste, there is the drying process, which is a food preservation method, influencing the preservation time, quality and durability of food. The choice of convective drying technique is due to simplicity and low cost of installation and operation of this equipment used. The convective drying using hot air, increasing the air temperature, reducing its relative humidity and absorb moisture available on the material to be dried. In this study, we investigated the process of convective drying mullet, to determine the drying time by testing in a test rig constructed in the laboratory making use of alternative materials and also test the mathematical model of the second Fick’s Law with proper comparison with experimental data. Drying was performed on mullet fillets subjected to a temperature of 48 ° C and air velocity of 2.5 m / s in the alternate drier with forced convection and also commercial greenhouse with natural convection, making mass measurements of fish every 15 minutes. The experimental results showed that the dehydration of mullet fillet was faster in alternate dryer compared to the process in commercial greenhouse. An adjustment of the effective diffusivity coefficient resulted in the range of 2.10-10 to 2.7.10-10 m2/s for the mullet fillets evaluated and maximum relative error of 5% between the numerical results and experimental data. The empirical models of fourth degree polynomials and logarithm had the best fit with the experimental dat.