(613e) Development of Technology for Small-Scale Drying of Fish and Its by-Products

A technology for small-scale drying of fish has been developed, tested and demonstrated to a group of artisanal fish processors at the Dar es Salaam Ferry fish market. A matrix of factors for choice of technology was developed and used to determine the most suitable technology between saw-dust drying, solar driers, and oil burner. The technology for heavy fuel oil burner with air-flue gas heat exchanger was selected which can be converted to use waste oil 130,000 Btu/gal as energy source. The fish were put on wire mesh trays and stacked in shelves installed inside a tray drier chamber measuring 6 m L x 3 m W x 2.7 m H. Different types of fish like Anchovy- Stolephorus baganensis; Ponyfish- secutor insidiator; and Herring- spratelloides delicatulus were dried. The envisaged drier capacity is 1.0 ton/day accommodating 250 kg of fish per batch each taking 2 hours for drying and one hour for loading and unloading. A desired drying temperature of 70 oC could not be uniformly attained throughout the chamber due to lack of mechanism to distribute the hot air. The product obtained was packed and subjected to water activity and culinary tests, which showed a water activity of 0.6 and 90% acceptance in favor compared to similar products in the market for aspects like taste, appearance, and softness after cooking. More work need to be carried out prior to dissemination of the technology. This include optimization of the drier parameters like: (i) uniform distribution of hot air inside the chamber; (ii) establishing suitable purging schedules to remove moisture load during operation; (iii) installation of a parallel chamber so that the oven doesn't have to be switched off during unloading and loading; and (iv) establishing comprehensive cost-benefit analysis once sufficient data has been gathered.