Drying characteristic of local fish cracker from several manufacturers using different drying techniques

Abstract

This study focuses on improving the existing drying processes for optimum production of premium quality fish crackers. The main purpose of this study was to investigate the effect of different drying techniques (sun, oven and vacuum) used on the drying characteristic of local fish cracker snacks from two different manufacturers. The drying characteristics were represented by the moisture content (MC) and the drying rate of the fish cracker. Higher reduction of MC was observed with the thinner fish cracker from Perusahaan Hasil Laut Musliha compared to thicker fish cracker from Persatuan Nelayan Kawasan (PNK), Tanjung Dawai for all types of drying techniques. It is important to establish the equilibrium moisture content (EMC) corresponding to the drying time as it could minimized energy consumption and transportation cost. The region of falling rate period for PNK and Musliha fall at MC range 0.8085-0.6624 gH2O/gDm and 0.5238-0.1396 gH2O/gDm for vacuum drying, 0.7223-0.0987 and 0.3801-0.1007 gH2O/gDm for oven drying, and 0.6641-0.1478 and 0.3571-0.1272 gH2O/gDm for sun drying method, respectively. Furthermore, Lewis model was applied to predict the drying kinetics of the fish cracker from both manufacturers and compare with the experimental data. The best fit experimental data to predicted was statically compared based on the coefficient of determination (R2), sum square error (SSE), root mean square error (RMSE) and reduced-chi square (X2). Among the drying techniques used, vacuum drying showed the best fit to the model. Lastly, moisture transfer from the fish cracker was described by applying the Fick’s diffusion model. The values of effective moisture diffusivity (Deff) obtained from this experiment lie within the range from 10−9 to 10−7 m2s−1.