Studies on Some Major and Trace Metals in Smoked and Oven-Dried Fish

Abstract

The mineral (Li, Na, K, Ca, Mg, Fe, Cu, Mn, Zn and Pb) composition of each of five species of fish, including Sarotherodon galilaues, Cyprinus carpio, Clarias gariepinus, Sardinella spp. and Labeo spp. Was determined in samples previously dried, either by traditional smoking method, or in laboratory oven, to gain knowledge of the quality and acceptability of the smoked products. The samples were brought from markets in Minna metropolis, Niger State of Nigeria. Portions of the meals of whole fish were digested in a nitric acid-hydrogen peroxide-perechloric acid (3:11) mixture and the digests were analysed spectrophotometrically. The concentration of lead was lowest in both smoked and oven-dried specimens with mean values ranging from 0.46 to 1.16mg/kg and 0.54 to 0.76mg/kg, respectively, while calcium with ranges of 592.98 to 7553.55mg/kg and 498.65 to 6460.85mg/kg was highest. Comparative studies showed that no significant differences existed between the mineral contents of the samples from the two drying methods, except in the few cases of lithium in S. galilaeus, zinc in C. gariepinus, copper and manganese in both Cyprinus carpio, and Sardinell spp, and lead in S. galilaues. Nonetheless, the smoked samples were consistently richer in their mineral content, suggesting the need for chemical examination of products of this drying method. Journal of Applied Sciences and Environmental Management Vol. 8 (2) 2004: 5-9