Comparative evaluation of three traditional smoked anchovy storage structures at Akplabanya

Abstract

Three different techniques used for the traditional storage of smoked anchovies (Anchoa guineensis) by artisanal fish processors at Akplabanya (a coastal fishing village near Ada, in the Greater Accra Region of Ghana) were studied, and the major structural features, material requirements and methods of construction were determined. The storage techniques include: (a) the round oven storage, (b) the sea-sand platform storage structure, and (c) the fenced yard structure. A comparative assessment of their relative efficacy in the preservation of smoked fish quality during storage was undertaken over a three-month period. Freshly smoked anchovies (Anchoa guineensis) were stored the traditional way and samples taken at 0 and 3-month intervals to determine the physical, chemical, microbial and sensory characteristics. Changes in the environmental conditions in the storage structures were monitored with a Telog temperature/humidity recorder. In general, all the structures are built with mainly locally available materials; and the choice of any of the three depends on factors such as capital input available and the volume of smoked fish to be stored. The most effective technique in terms of structural protection against environmental hazards and storage pest was the mud oven structure, followed by the sea-sand platform method. The fenced yard did not protect the stored product against insects, rodents and domesticated pests. The polyethylene cover could only protect the samples against rain damage. A fairly constant average temperature of 30-33ᵒC was maintained most of the time in the round oven structure, while the sea-sand platform structure recorded a range of 28-38ᵒC. A steady drop in relative humidity from about 60% to 42% was also observed in two structures. Although the fenced yard structure also maintained average temperatures between 28 and 38ᵒC, it however, recorded very drastic humidity increases from 42% to as high as 71%. The moisture content of samples did not change with storage time. The freshly smoked sensory quality attributes and physical characteristics of the smoked anchovies were adequately preserved by the traditional round oven and sea-sand platform storage structures. Storage yield in terms of overall physical damage was 91.5%. Proteolytic, lipolytic and microbial deterioration was minimal. The fenced yard storage method however, caused a significant decrease in the aroma and flavour of the samples. In general, the microbial loads for the smoked fish were low, especially in the samples stored by the round oven and sea-sand platform techniques. The relatively poor structural protection offered by the fenced yard structure facilitated the invasion of insects, rodents and domesticated pests which caused significant increases in the numbers and types of contaminating microorganisms. Maximum aeration existing in the structure also enhanced the growth of more aerobic organisms. The detection of indicator organisms such as coliforms and especially faecal coli in the samples stored by the fenced yard method makes these samples unwholesome for consumption. Microorganisms isolated were Rhizopus, Aspergillus spp., Micrococci, and Bacillus sp.