Effect of traditional storage on the quality of smoked anchovy (Anchoa guineensis) at Tema Manhean

Abstract

The most widely used traditional storage techniques for smoked anchovies by artisanal fish processors at Tema Manhean (in the Greater Accra Region of Ghana) was studied, and the major structural features, material requirements and method of construction were determined. The structural characteristics established in the study were used to construct a prototype anchovy storage structure in the village to determine the effectiveness of the traditional structure. Freshly smoked anchovies (Anchoa guineensis) were stored the traditional way and samples taken at 0, 3 and 6 month intervals to determine the microbial, mycotoxicological, physical, chemical and sensory characteristics. Change in environmental conditions in the storage were monitored with a Telog temperature/humidity recorder. Storage temperature increased by about 2ᵒC within the fisrt three months and thence dropped to the original average value of about 30ᵒC. The humidity in the structure on the other hand, decreased steadily from an initial value of 66.7% to as low as 45.5% at the end of the six month storage period. This situation resulted in the drying of the smoked fish during storage, thus enhancing preservation. The moisture content of samples decreased from 13% to less than 10% resulting in slight increases in sensory attributes such as hardness, brittleness and chewiness. There was only a slight decrease in flavour, but aroma and colour remained the same. Storage yield in terms of overall physical damage was 85%. Proteolytic, lipolytic and microbial deterioration was minimal, occurring mainly in samples at the periphery of the structure. The edible portions of the fish samples had less bacterial load than the whole fish, but the mould count was approximately the same for both samples. In general, the microbial loads for the smoked fish were low, ranging between 760 and 850 bacterial organisms per gram of fish and between 320 and 450 moulds per gram. Microorganisms isolated were Rhizopus, Aspergillus spp., Micrococci, Bacillus sp. and Yeasts. Coliforms as well as faecal coli and pathogenic microorganisms were absent from both whole fish and edible portions of the smoked anchovies; a good indication of hygienic processing and storage conditions. The stored fish samples were also negative for aflatoxins B₁, B₂, G₁ and G₂