Quality changes during short term storage of smoked anchovy at Tema Manhean

Abstract

A prototype traditional anchovy storage structure was constructed at Tema Manhean (in the Greater Accra Region of Ghana) and freshly smoked anchovies (Anchoa guineensis) were stored the traditional way for a period of three months. Samples were taken at 0 and 3 month intervals to determine the microbial, mycotoxicological, physical. chemical and sensory characteristics. Changes in the environmental conditions in the storage were monitored with a Telog temperatures/humidity recorder. Storage temperature increased by about 2ᵒC within the first three months from 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 53.6% at the end of the three month storage period. The moisture content of samples did not show any significant change, while slight increases were observed in sensory attributes such as brittleness and chewiness. There was only a slight decrease in flavour, but hardness, aroma and colour remained the same. Storage yield in terms of overall physical damage was 91.4%. Proteolytic, lipoytic 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 first three months of storage was characterized by a rapid proliferation of bacteria resulting in high viable aerobic counts. Mould growth was however not favoured much. 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 the 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