Effect of sun-drying, smoking and salting on proximate composition of fresh fillets of mcheni (Rhamphochromis species - Pisces: Cichlidae) from Lake Malawi, Malawi

Abstract

A study was conducted to determine effect of sun-drying, smoking and salting on proximate composition of fresh fillets of Rhamphochromis species fish (local name: Mcheni) from Lake Malawi, Malawi. Fresh fillets prepared from the fish were sun dried, sun dried then smoked, smoked fresh, salted then sun dried, and salted then smoked. The processed fillets were then analysed for proximate composition. Highest and lowest moisture content was observed in fish that were salted then smoked (28.99±0.02) and sundried then smoked (8.56±0.51) (P<0.05). Sundried and salted then smoked fish had the highest and lowest protein (53.68±0.79, 32.53±0.17) and energy (24.00±0.05, 16.31±0.02) levels respectively (P<0.05). More fats were retained in sundried fish (27.25±0.02) while fish that were salted then sundried had the lowest fat content (11.09±0.05) (P<0.05). Salted then sundried fish had more ash (18.83±0.12) while lowest ash levels were observed in fish that were smoked (5.03±0.03). A general observation was that sundried fillets had higher protein, fat and energy content while smoking significantly reduced nutrient levels. On the other hand, salting increased ash levels in the fillets and a combination of sun drying and smoking helped to produce a product with very little moisture content. Results suggest that consumers would have a more nutritive product by avoiding adding salt to Rhamphochromis fillets but rather sun drying and smoking. The lowest moisture content in sundried and smoked fillets also suggest a processed product with a longer shelf life as moisture favours microbial growth that are responsible for most spoilage in fresh foods.