Genesis: It refers to the time or circumstances of something’s coming into being e. g. the genesis of a new project (Microsoft Corporation, 2008). It can be simply put as ‘a coming into being’ (Franc Morales, 2009). Kiln: It is referred to as a furnace for firing or burning or such things as porcelain or bricks (Franc Morales, 2009). It is also referred to as any of several kinds of furnace, heated electrically or by the combustion of fuel, used to fire pottery or other ceramic products, to roast ores, or in the production of cement (Microsoft Corporation, 2008).
Relating these definitions together to aquaculture and fisheries, one can say that a kiln is a furnace for smoking, drying and preservation of fish. Oven: It is a kitchen appliance used for baking or roasting (Franc Morales, 2009). It also refers to a compartment warmed by a heat source used for baking, roasting, or drying (Microsoft Corporation, 2008). Joining the definitions of kiln and oven together, one can say that a kiln-oven is an implement used for preservation of fish.
From all these deductions, one could therefore conclude that the topic ‘Genesis of modern modified kiln from the traditional kiln oven’ simply refers to the time or circumstance of the modern modified kiln’s coming into being from the traditional kiln. Genesis of Modern Modified Kiln from the Traditional Kiln Oven (Adapted from Olokor et al) Smoking as a method of preservation of perishable foods dates back to civilization. Fish and fishery products are one of the most perishable of all staple commodities. They are therefore, suitable media for the growth and proliferation of micro-organisms (Jay, 1986).
To prolong the shelf life of fish, fish is preserved by smoking. Smoke is generated from wood by burning. Smoke has bacteriostatic, bactericidal and antioxidant functions while heat generated from the wood has dehydrating effect on the fish (Eyo, 2001). The combinations of these processes give fish dry effect. Hence a well smoked fish can be kept in storage for months without undergoing spoilage. Fish smoking is the traditional occupation of artisanal fishermen and women in Nigeria with simple traditional ovens.
There are different types of local ovens being used depending on the location. In the northern part of the country, Banda is used generally while in the south, it ranges from simple pit ovens to drum oven. The most important advantage of these simple ovens is the low capital cost. However, many disadvantages have been reported which include: I. Inefficient utilization of fuel wood II. Poor quality of fish due to lack of control over the temperature of the fire and the density of smoke (Clucas, 1995) among others.
To arrest these problems many workers have invented improved smoking kilns such as Chokor Kiln, Altona/Watanabe Smoking Kiln, Ivory Coast Kiln, Magbon Alade Kiln, Kainji Gas Smoking Kiln, Improved traditional smoking kiln and Modified Drum Kiln (MDK) among others. The merits of these kilns include: fuel efficiency, good quality products and high batch capacity. A description of a selected few is as follows: Chokor kiln The kiln originated from Ghana in Chokor village from where it derived its name and is an improvement on the traditional smoking kiln.
The kiln is rectangular in shape and has a mud, cement or back wall of inter nal dimensions of 0. 7m x 0. 7m x 0. 7m. The top of the wall is flat to enable the wooden frame trays sit snugly against them. This version has two chambers and each chamber has centrally placed stoke hole, 38cm high and 38cm wide. The wooden smoking trays have dimension 0. 8m x 0. 8mx 0. 7m and consists of chickenwire mesh nailed to the wooden frame. The smoking trays have a pair of handles on the opposite for lifting together. Up to 15kg of fish can be smoked on each tray.
During smoking, the wooden trays with fish are stacked to enhance the capacity of the kiln. Up to 5 trays may be stacked to form a chimney in which heat and smoke circulate constantly (Eyo, 2001). The last tray is then covered with a ply wood sheet till the smoking process is complete. The rate of adoption of this kiln in Nigeria is high. Advantages of Chokor Kiln 1. It is fuel efficient 2. It is easy to operate and maintain 3. Produces evenly smoked fish which fetches a high price in the market 4. High batch processing capacity 5.
Durable if protected from rain Improved Banda (IMB) The improved Banda is a modification of the traditional rectangular mud-type smoking kiln (Adelowo et al, 1998). The structure is simple and can be constructed by the local fish processors. Its simplicity and efficiency in utilization of fuel wood accelerate its adoption by the local fisherfolks (Eyo, 2001). It is a rectangular structure with a dimension of 120cm x 70cm x 70cm. the fire box is reduced in size to allow limited air ingress and escape of smoke. The dimension is 30cm x 30cm. he significant feature of the kiln is the presence of a damper, a perforated metal plate that prevents direct contact of fire with fish, thus fish loaded on the bottom trays close to the fire do not get charred. It is covered with framed zinc together with a chimney that serves as escape route for excess smoke. The improved Banda is equipped with 3 trays where fish is arranged for smoking. The fish is prepared and loaded in the tray. After loading, firewood is ignited in the firebox and the smoking operation commences.
Advantages of Improved Banda 1. Using this kiln, fuel wood consumption is reduced to 52% compared with the traditional smoking kiln 2. The quality of the smoked fish is also high and acceptable to consumers 3. It Is less labour intensive 4. It is cheaper to construct than most improved kilns. Modified Drum Kiln (MDK) The kiln is made from a 400 litre capacity drum with a length of 90cm and diameter 58cm. he drumis cut open midway using a motorized welding nozzle. The base of the drum is cut open midway using a motorized welding nozzle.
The base of the drum is used as the combustion chamber with the firebox measuring 22 x 22 cm2 cut out from the base. An internally built damper made of perforated metal plate is installed 1 cm above the fire box. The smoking chamber is separated into 3 compartments 10m above the damper. The first rack is installed covered with a chicken mesh to form the first smoking chamber. In the second and third compartment of the drum are fixed racks and chicken mesh to serve as the second and the third smoking chamber respectively.
Above the smoking chamber, the kiln cover is attached . t an angle of 40° above the cover, a metal pipe of 4 cm was in corporate to serve as the chimney. Advantages of Modified Drum Kiln 1. It is fuel efficient compared with the traditional drum kiln 2. Produces good quality fish that command high price and is acceptable to consumers 3. It is less labour intensive 4. It is very simple to construct 5. It is cheaper to construct than most improved smoked kilns 6. It is portable and can be carried on fishing boats. IMAGES OF TRADITIONAL AND MODERN KILN OVENS Fishing Village, Ghana
A fishing village in Ghana, a country in West Africa, employs mud ovens to dry its fish. The country derives its annual fish catch from the Atlantic Ocean and from inland waters, such as Lake Volta, one of the largest artificial lakes in the world. Jane Schreibman/Photo Researchers, Inc. Source:Microsoft Corporation, 2008 Ilamo landing centre, Ogun watersideFish Preservation Programme, NIFFR The fisher folk use the traditional drum kiln. The modified drum kiln is used. Source: Dimowo, 2011 (Field survey)Source: Dimowo, 2011 (Field survey) REFERENCES
