Distribution of heavy metals in fish organs, associated water and sediment from Ero Dam, Ekiti State, Nigeria

An investigation into the distribution of lead, manganese, copper, zinc, mercury, iron, chromium and cadmium in the sediment, water and the organs of Oreochromis niloticus, Tilapia zillii, African catfish (Clarias gariepinus) and Citharinus citerus obtained from Ero Dam in Ikun-Ekiti, Ekiti State, Nigeria was undertaken. This was done to ascertain the presence of these metals in the three matrixes and to determine the bioaccumulation factors of these metals in the organs of these fishes. The three matrixes were differently digested and analysed for heavy metals using Atomic Absorption Spectrophotometer (Buck 200). Hg was determined via cold vapour generation. The levels of the metals in water were very much lower than their corresponding concentrations in the sediment. In the same vein, concentrations of the metals in the fish organs were higher than those recorded for the water except Cu and Mn that showed slight variations. The most concentrated metal in the organs of the four fish species was Zn which recorded concentrations (mg/kg) ranging from 7.36±0.03 in the head of Clarias gariepinus to 8.12±0.13 in that of Citharinus citerus. In Clarias gariepinus, Cr, Cd and Hg were only detected in its gills. On the contrary, all the metals were detected in the organs of Oreochromis niloticus and Tilapia zillii. Zn, Mn and Fe were the three most abundant metals in the organs of these fishes. The highly toxic metals (Pb, Cd and Hg) in this determination were either not detected or detected at low levels. It is obvious from this work that Zn was bioaccumulated most in the organs of each fish. It is certain that heavy metals are present in Ero dam but in low concentrations. This calls for constant monitoring because as industries are established in Ekiti State, Nigeria, the level of heavy metals in this dam may increase.Keywords: Oreochromis niloticus, Tilapia zillii, Citharinus citeru

Proximate, mineral composition, antioxidant activity, and total phenolic content of some pepper varieties (Capsicum species)

Four varieties of the red pepper fruits (Capsicum species) were evaluated for chemical composition, antioxidant activity and total phenolic contents using standard analytical technique, ferric-ion reducing antioxidant potential (FRAP) assay and Folin-Colcalteau method respectively. The proximate composition values (%) were: moisture (82.54 – 85.19), crude protein (2.64 – 3.51), ash (1.21 – 3.03), fat (1.52 – 2.87), crude fibre (2.37 – 4.71) and CHO (4.62 – 6.71). Minerals were of reasonable levels with Na, K, Ca, and P significantly high in Capsicum frutescens ‘Bird pepper’. Na/K and Ca/P values were found to be less than1 except in Capsicum frutescens (cayenne pepper). Antioxidant activity ranged from 46.66 (bird pepper) – 172.00 (cayenne pepper) mg GAE/100 g ww) while total phenolic content ranged from 55.73 (bird pepper) – 138.00 (bell pepper) ìmole GAE/g WW. The results indicate that Capsicum frutescens bird pepper (Ata wewe), Capsicum frutescens (cayenne pepper) (Ata Sombo), Capsicum annum (Bell pepper) (tatase), and Capsicum annum sweet pepper (Atarodo) used as major condiments in preparation of traditional diets in Nigeria can be utilized as sources of protein supplement, valuable minerals and dietary antioxidants. They canserve as scavengers of free radicals reported to be associated with occurrence of chronic and degenerative diseases such as cardiovascular diseases.Keywords: Peppers, phytochemicals, Nutritional composition, Free radicals, Disease