International Journal of Computational Engineering Research||Vol, 03||Issue, 6|| www.ijceronline.com ||June ||2013|| Page 38 An Automated Combined Microwave and Electric-Element Fish Dryer Boyo H. O. 1 , Boyo A. O. 2 , Osibona A. 3 , Ishola F. 4 1 Department of Physics, Faculty of Science, University of Lagos 2 Department of Physics, Lagos State University, Ojo, Lagos 3 Department of Marine Science, Faculty of Science, University of Lagos 4 Hardware Development Laboratory, University of Lagos I. INTRODUCTION There is enormous waste through spoilage of both fresh and dried fish. Preservation of fish therefore generally slows down spoilage. Preservation methods are applied with an intention to making the fish safer and extend its shelf-life [1], [2]. Drying is a complex process that causes physical, chemical and bio-chemical changes in fish products. Hence there is no guarantee on the appearance and taste of dried fish products. The method of drying and drying condition determines the qualities and shelf life for preservation and export standards In Nigeria the quality of the taste of dried fish sold in the markets vary widely since there are no quality standards for the products. Productions are done using local methods which are neither hygienic nor standardized. Presently there is lack of information in the literature about change in quality in the taste of fish after drying and such information is necessary for the development of standards and for quality control purpose. Drying is a mass transfer process resulting in the removal of water or moisture by evaporation. To achieve this, there must be a source of heat. This work utilizes the conventional electric heater combined with the microwave dryer as the source of heat. II. MATERIALS A combined electric hot air flow and microwave drying unit was designed to have the following parameters; Combined 1.6kW twin microwave gun, 4kW quad electric element. The oven cavity has a total volume equal to 897,000cm 3 and can contain wet fish cargo capacity of 80kg at once. The guns and heaters are automatically controlled with microcontrollers. The microwave generated by the Magnetron is focused with a WR-340 D-Band rectangular waveguide and a pyramidal aperture horn antenna (figure 1). The waveguide operates at 2.45GHz frequency [20 percent higher than cut-off frequency] propagation in TE 10 mode. ABSTRACT This work provides an improvement in the efficiency and economics of the drying process by combining an electric hot air flow and microwave drying unit. It is intended to improve the nutritional qualities for the dried fish market and its shelf life. We fabricated a drying Kiln having combined 1.6KW twin microwave gun and 4KW quad electric element, volume 897,000cm 3 and wet fish cargo capacity up to 80Kg. The characteristics of electric drying (ED) and combined microwave-electric drying (MED) of Clarias Gariepinus tissues were studied experimentally. Results show that the moisture ratio decreases with an increase in microwave drying time when microwave power is fixed. The drying rate is fast initially and then falls slowly. Finally, the curve of MED was steeper than that of ED alone during the initial drying period. The data of the percentage of water and volatile oil loss by drying with respect to time follows a logarithmic relationship. The taste panels evaluations and sample results of organoleptic assessment of the dried Clarias Gariepinus was found to range from excellent quality for appearance, taste and odour, good quality for fragmentation and texture. The addition of microwave to the electric heater has saved about 28 hours in drying time and reduced the product cost by energy consumption to 38%. In conclusion this method provides rapid dehydration (shorter drying time), improved product quality and flexibility in drying a wide variety of products. KEYWORDS: Microwave Electric Drying, Internal Moisture, Nutritional Qualities