Oladapo A. Afolabi

Heavy metals in the lagos lagoon sediments

Concentrations of cadmium, cobalt, copper, chromium, iron, manganese, nickel, lead and zinc were determined in surface sediments of the Lagos Lagoon, Nigeria. The results revealed largely anthropogenic heavy metal enrichment and implicated urban and industrial wastes and runoff water transporting metals from land‐derived wastes, as the sources of the enrichment. Higher levels (F < 0.05) of cadmium, iron, manganese, nickel and zinc occurred in sediment samples collected near industrialized‐urban areas than in those from unindustrialized‐rural areas only in the wet season. While iron constituted about 1% of dry sediment by weight, the other metals were present in trace amounts.

Rapid transesterification and mass spectrometric approach to seed oil analysis

Fatty acid composition of seed oil is determined in less than one hr using a quantitative one-vial technique. The method of analysis requires alcoholic solutions of sodium methoxide mild enough for epoxy and polyunsaturated oils. Separation and characterization of component fatty acids were accomplished by high resolution gas chromatography-mass spectrometry.Using this method,Vernonia galamensis seed oil is shown to contain 79–80% vernolic (cis-12,13-epoxy-cis-9-octadecenoic) acid.Amaranthus cruentus, a West African vegetable crop, is shown to contain 17.3% palmitic acid, 3.2% stearic acid, 22.7% oleic acid, 54.7% linoleic acid and 2.1% linolenic acid.

Chemical composition of papaya (Carica papaya) seeds

Abstract Defatted and undefatted seeds of papaya (Carica papaya) were analyzed for proximate composition, some toxicants, sugar composition, mineral content, physico-chemical properties of the seed oil and the fatty acid spectrum of the seed oil. The seed is a rich source of proteins (27·8% undefatted, 44·4% defatted), lipids (28·3% undefatted) and crude fibre (22·6% undefatted, 31·8% defatted). Of the toxicants estimated, glucosinolates occur in the highest proportion. The seed is low in free monosaccharides. Sucrose is the predominant sugar (75·0% of total sugars). Mineral content is generally low. However, Ca and P occur in appreciable quantities (17 340 μg/g and 10 250 μ/g, respectively). The seed oil is low in iodine value (74·8), free fatty acids (0·94%) and carotene (0·02 μg/g). The major fatty acid is C18:1 (79·1%).

Synthesis of Toughened Elastomer from Vernonia galamensis Seed Oil

AbstractsThis paper examines the synthesis of a toughened elastomer fromVernonia galamensis seed oil by reacting vernonia oil with vernonia oil-derived suberic acid (octanedioic acid), and cross-linking the pre-polymer in the immediate presence of cross-linked polystyrene preparedin situ. The paper also demonstrates that the progress of reaction can be followed by monitoring the generation of hydroxyl groups using infrared spectroscopy. Analysis of some crystalline material on the cooler parts of the reaction vessels revealed the presence of component fatty acids of vernonia oil. Transmission electron microscopy characterization of the synthesized toughened elastomer suggests that vernonia oil-suberic acid polyester and polystyrene polymer are interpenetrating.

Determination of fatty acid composition of amaranthus species

Fatty acid compositions of the seed oils from eighteen vareties of amaranthus species have been determined after room temperature transesterification. Consistent with earlier studies, wide variations in the fatty acid composition are reported, and appear to be agronomically related. All variaties show significant levels (2–5%) of squalene and a combined linoleic acid and olaic acid occurrence of between 70–-80%. This study represents the frist reported fatty acid composition of grain amaranthus cultivated in West Africa.

Studies on some edible wild mushrooms from Nigeria: 1. Nutritional, teratogenic and toxic considerations

The biological value of 5 mushroomsChlorophyllum molybditis, Psathyrella atroumbonata, Termitomyces robustus, Termitomyces striatus andVolvariella esculenta from our collection of wild edible mushrooms were determined using weanling rats.C. molybditis supported rapid growth with PER (2.63) higher than the casein control (2.50).P. atroumbonata was average in biological performance (PER 1.50) whileT. robustus andV. esculenta did not support growth at all. Rats onT. striatus dried at 60°C for 48 h lost weight rapidly and showed pathological signs of toxicity by the second day. All rats on this died died by the fourth day of the experiment. When the diet ofT. striatus dried at 90°C for about 8 h was fed, the rats gained weight marginally but all survived. Prolonged storage ofT. striatus at 60°C for 5–8 weeks also seemed to detoxify the poisonous component such thatPER andNPR values were 0.8 and 2.0 respectively. 2 pairs each of adult rats fedC. molybditis andTricholoma lobayensis diets for 10 days were mated. Rats ofC. molybditis diet gave 5 and 6 litters each and only one of these litters seemed to have retarded growth. Rats onT. lobayensis diet did not produce any litters for 14 weeks but the female produced off-spring when mated with control male rats.

Some studies on the proteins of Carica papaya seeds

Abstract Protein isolates and seed meals made from Carica papaya seeds were studied with respect to their composition and functional properties. Studies showed that the seed proteins are most soluble in 5% NaCl (23·77 ± 0·15%). In all concentrations of NaCl tested, the protein has a solubility peak at pH 8·0. Classification of the protein showed that globulins constitute the bulk of the protein (53·9 ± 0·89%). The amino acid pattern of the samples studied is not too different from other plant protein sources. However, the seed appeared deficient in many amino acids. Electrophoretic studies showed that the water extract had only one band with a molecular mass of about 70·7 × 10 3 daltons. The 5% NaCl extract gave five bands, with molecular mass ranging from 37·6 to 105·9 × 10 3 daltons while the NaOH-soluble fraction gave six bands with a range of 18·2 to 104·0 × 10 3 daltons. Compared to soya bean meal and protein concentrate, the papaya products were inferior in terms of functional properties.

Quality assessment of laminated fillet blocks from blue whiting (Micromesistius poutassou)

Abstract Laminated fillet blocks made from blue whiting (Micromesistius poutassou) caught in February and April were assessed for quality. The total protein nitrogen value in February-caught fish was greater than the April-caught fish. The bone content, water content and pH values were consistently lower in the February fish than the April fish. Measurement of the acceptability of deep fried, breaded fingers made from the fish and compared with cod fingers produced from fish caught at the same time of year showed a consistent difference between the cod and blue whiting. In addition, the fish fingers from fish caught in February scored consistently higher than those caught in April. The implications of the findings are discussed.

Gaping studies in blue whiting (Micromesistius poutassou)—The effect of prefreezing treatments

Abstract Blue whiting caught in January and April were stored in ice, iced sea water and at ambient temperature for varying lengths of time before freezing on board. Thawed fish samples were scored for gaping. The results indicate that storage in iced sea water before freezing reduced both gaping and the seasonal variability of the degree of gaping in the blue whiting.