CHAPTER ONE
1.0 INTRODUCTION
1.1 Background InformationFish is an important source of cheap first class protein, providing essential amino acids(Aremu et al., 2014), it is an indispensable source of micronutrients (Okonji et al., 2016) andother elements for the maintenance of healthy body (Ravichandran et al., 2012; Ehigiator etal., 2015). The results of a study conducted by Sipe (2008) have shown a positive correlationbetween the amounts of fish consumed and life span of the consumer. Aremu et al. (2014)reported that majority of Nigerians, Americans and Japanese who depend on fish as theirmain source of protein have longer life span.In spite of the importance of fish and the fishing industry, fish is an extremely perishablecommodity, spoiling soon after death, due to enzymatic and microbial actions, resulting indisagreeable taste, smell and texture, thereby reducing consumer acceptability (Garrow andJames, 2004; Emine and Bahri, 2015). Various factors are responsible for fish spoilage,notable among these factors are fish health status, the presence of parasite, bruises andwounds on the skin and the mode by which the fish was captured (Omoruyi et al., 2016).Aremu et al. (2014) also asserted that high ambient temperature of the tropics are a majorenvironmental factor prompting rapid spoilage of fish. Hence, careful handling and rapidprocessing are essential steps to overcome the problem of rapid fish spoilage.Preservation and processing are means of prolonging the shelf-life of fish products inacceptable quality through changes in texture, taste and appearance without adverselyaffecting the chemical nature of the product. Processing and preservation refers to some ofthe ways in which the mechanism which cause fish spoilage are slowed down or stopped(Ray, 2010). Fish processing on the other hand usually change the texture, taste, physicalappearance of the fish so that deterioration is slowed or halted but the fish change1
characteristics according to the process used (Madu, 2016). The main objectives ofprocessing fish are to prevent increase in microbial load and other enzymatic reaction andkeeping the fish in an acceptable way between the time of capture or harvest and consumption(Omoruyi and Abolagba, 2015). In order to avoid spoilage which leads inevitably to postharvest losses several methods of preservation can be employed to prolong the shelf life offish while still maintaining its nutritional, economical and physical content. They includedrying, salting, freezing, canning, smoking (Akinola et al., 2006; Omoruyi et al., 2017).Smoking of fish is a major way of preserving fish in Nigeria. Smoking of fish has theobjective of preservation basically due to dehydration and high temperature of smoking(50 – 180oc) (Omoruyi and Ebhodaghe, 2017). Bacteriostatic, bacteriocidal and antioxidantfunctions of smoke and the dehydration effect of the process were used inadvertently by theearly fish processors in the preservation of fish (Aremu et al., 2014). Although consumers aregenerally attracted by the flavour of smoke-dried fish, its nutritive value is of paramountimportant since every consumer wants to obtain good quality protein from fish consumption(Raffray et al., 2014). Acceptability of smoke-dried products however depends on the type of fuel material used(Yola and Timothy, 2012). Wood selection must be done with care as some wood likeresinous types for example pine may impart unpleasant flavor and taste to the final product;while others like Euphobia species may be poisonous (The United Nations DevelopmentFund for Women/UNIFEM, 2008). Although many wood types may be used as fuel for fishsmoking among the many factors influencing the choice of wood, what is used depends onlocal availability. The fuel wood preferences of most fish smoker are also related to thephysical characteristics of the wood and how they affect the smoked product (Yola andTimothy, 2012). Different fuel material may affect the quality of the smoked fish differently