Nutritional quality of Barbus paludinosus (matemba) smoked using traditional and improved smoking methods

Abstract

Proximate composition (crude protein, moisture, crude fat and ash) and calcium of Barbus paludinosus locally known as matemba, smoked in traditional and improved smoking kilns was compared. This species makes the most important fishery in Lake Chilwa, Malawi. Matemba is also highly nutritious because it is consumed whole due to its small size. Most of the catch is either sun dried or smoked. However, knowledge that heat processing compromises nutrient content in food products, underpins the need for assessing the magnitude of nutrient changes or losses in the respective processed products. In this study, freshly caught fish samples were obtained from Lake Chilwa (Southern Malawi), smoked and analysed for proximate composition. Crude protein significantly increased (61.00 ± 0.02) (P<0.05) and decreased (59.50±0.03) (P<0.05) from the normal (fresh samples – 60.50 ± 0.01) in fish processed using the improved and traditional smoking kiln respectively. Fish smoked in the traditional kiln showed higher amount of moisture (19.00 ± 0.02) than the improved kiln (18.00 ± 0.03) (P<0.05). Higher amount of crude fat, ash and calcium were retained in fish smoked in the traditional smoking kiln compared to the improved smoking kiln (P<0.05). Summary results suggest that the improved smoking kiln is better in preserving nutrients in fish over the traditional smoking kiln. Of much interest in the improved smoking kiln, is the higher protein and lower moisture retention. This suggests that fresh fish smoked in the improved kiln is more nutritious but also may have a longer shelf life due to lower moisture which is a medium for microbial growth responsible for fresh food spoilage. The improved smoking kiln should therefore be recommended also because it uses less firewood than the traditional smoking kiln. However, the traditional smoking kiln may not be eliminated completely owing to products with higher fat content which is also required by the human body