Effects of smocking and sun drying on proximate composition of diplotaxodon fish species (NDUNDUMA) from Lake Malawi, Malawi

Abstract

Processed fish and fish products have high nutritional value, longer shelf life and fetch better prices on the marketin contrast to freshlycaught fishwhich are highly perishable. Processing,however, alters nutrient composition of a productunderpinning the need for caution when consuming processed products. The study analyzed the effect of traditional smoking and sun drying on proximate composition (moisture, protein, fat and ash) of Diplotaxodonspecieslocally known as Ndunduma. Thisis an important commercial cichlid species harvested across the entire Lake Malawiby both artisanal and commercial fishers. Fresh Diplotaxodonfish samples were collected from fishers’ boats in the south-western partof Lake Malawi, Malawi immediately after catchearly in the morning. The fish were washed then weighed and thereafter,smoked in a traditional smoking kiln and sun dried on reed mats. Determined percent moisture, protein, fat and ash content forsmokedfish were: 12.22±0.05, 55.30±1.67, 25.31±2.78 and 12.96±0.72,respectively,while corresponding values for fish that were sun dried were: 24.28±0.14, 52.80±1.28, 22.36±0.26 and 13.81±0.14,respectively. Overall, results show reduced protein content inprocessed fish (smoked and sun dried)(P<0.05) although not significantly different in smoked fish (P>0.05).Significantly low moisture content in smoked fish is indicative of a product with longer shelf life since moisture favours rapid microbial growthcausing freshness quality deterioration. Although not significantly different, high fat (P>0.05) and ash (P<0.05) in smoked fish is consistent with a nutrient rich product. The study concludes that smoked Diplotaxodon species is more nutritious and may presentbetter storagequalities than sun drieddue to relatively low moisture. Caution should,nevertheless,be considereddue to the highfat levels to prevent spoilage caused bybreakdown of fats. Since smoked products areof high commercial value, fish processors should be encouraged to smoke fresh Diplotaxodon speciesother than sun drying.