Journal of Agricultural Science and Technology B 1 (2011) 108-114 Earlier title: Journal of Agricultural Science and Technology, ISSN 1939-1250 Drying of Fish Sardines in Oman Using Solar Tunnel Dryers M. A. Basunia,H. H. Al-Handali, M. I. Al-Balushi, M. S. Rahman and O. Mahgoub College of Agricultural& Marine Sciences, Sultan Qaboos University, P.O. Box 34, Al-Khod123, Muscat, Sultanate of Oman Received: June 25, 2010 / Published: May 20, 2011. Abstract: This paper deals with the design, construction and performance evaluation procedure of a solar tunnel dryer in drying fish. A 12 meter long and 2 meter width half-circled tunnel was designed and constructed to dry about 50-100 kg of freshly harvested fishes per batch. The half of the tunnel base was used as the flat plate air heating solar collector and the remaining half as a dryer. The drying air was forced from the collector region (north side) to the drying region (south side) of the half circled tunnel where the product is to be dried. The drying temperature could be easily raised by some 5-30 ℃ above the ambient temperature inside the tunnel at an air velocity of approximately 0.2 m/sec. The test was conducted with 51.5 kg freshly harvested sardines (half-load) with initial moisture content of 66.5% (wet-basis) to analyze the performance of the dryer. The fishes were dried to a final average moisture content of 15.5% (wet-basis) within three days (30 hours). It was possible to reach the moisture content level for safe storage within less than three days (30 hrs) with solar tunnel dryer and 7 days in open air natural sun drying. The improvement in the quality of fishes in terms of color, brightness, flavor, and taste and food value was distinctly recognized. Key words: drying, fish sardines, solar tunnel dryer, moisture content. 1. Introduction There are various methods and techniques commonly used to dry fishes. Each method has its own advantages and limitations. Dried products are becoming highly alternative to marketing than the freshly harvested products because of many advantages. The small pelagic landings in Oman, for example, were 41,496 tonnes, 80% of which were sardines (Sardinella longiceps) [1]. It means that there is a sufficient supply of sardines (i.e. 23,000 tons/year) to support the livestock feed industry. So the dried sardines are commercially used as a livestock feed. It is harvested all year round in Oman. Open air natural sun drying of fishes is practiced many part of the world. A major problem with traditional sun drying of sardines is the loss of dried products due to birds, rates, cats, dogs and insect Corresponding author: M. A. Basunia, Ph.D., research field: agricultural drying machinery. E-mail: basunia@squ.edu.om infestation. So a considerable loss (30-40%) is occurred [2]. These factors cause lot of losses to fishermen. Sardines are traditionally dried in Oman by spreading on a sandy beach for about a week in winter and 4-5 days in summer [2]. The quality of open air sun dried sardines is poor. In most cases the drying yard is not properly fenced. So the product is not protected against dust, rain and wind, or even against insects, birds, rodents and domestic animals while drying. Soiling, contamination with microorganisms and infection with disease-causing germs are the result. The fishes dried in this way have short shelf-life and may not be free from contamination. The solar drying facilities combine the advantages of traditional and industrial methods, namely low investment costs and high product quality. Many studies [2-6] suggested that drying rates are faster and qualities of dried fishes are much better than open air natural sun drying method.