Emmanuel Nwokolo

Nutritional evaluation of pigeon pea meal

Mineral, amino acid and fatty acid composition of pigeon pea meal were determined by analysis, while with chick essays, availability (true digestibility) of minerals and amino acids in the meal were estimated. Gross energy, metabolizable energy and true protein digestibility experiments were also conducted. Pigeon pea meal had a very high content of potassium, high content of potassium, high content of phosphorus, moderate content of calcium and magnesium and low content of iron, zinc, copper and manganese. Average availability of minerals was 58.09%. Amino acid content was low, especially cystine and methionine. Amino acid availability was 82.32%, lower than amino acid availability of soybean meal (>90%). Pigeon pea lipids were predominantly saturated fatty acids (69.04%) with low content of unsaturated fatty acids (30.69%) and a total absence of linolenic acid. Metabolizable energy content (N-corrected) was 11.08 MJ/kg in raw pigeon pea and 12.03 MJ/kg in toasted pigeon pea meal.

Melon (Colocynthis citrullus L.)

The melon, Colocynthis citrullus (L.), is a creeping annual of the Cucurbitaceae, many members of which grow in the tropics. The melon described here, is an unimproved form of the better known watermelon. In spite of its being less known in the western world, it is cultivated to a very great extent in tropical Africa, where the seeds constitute an important dietary source of protein and oil. The melon is a small, ovoid fruit, weighing 1–2 kg, containing a large number of seeds embedded in a bitter-tasting, watery, fibrous fruit. The seeds are dorsoventrally flattened and covered with brown-coloured, thin and brittle shells. Decorticated seeds (kernels), are white and soft in texture. Seed yield is estimated at about 2 tonnes/ha (Nwokolo and Sim, 1987). Yield of air-dry kernels is about 70–80 kg/100 kg of dry seed. In tropical countries of Africa, melon seeds are milled and usually cold-pressed or solvent-extracted for the oil. Another form of local oil extraction involves crushing the seeds, boiling them in water until the oil floats to the surface and is separated. The oil extracted using any of these procedures is clear, pale yellow in colour and has a faintly nutty odour and a bland taste.

Compositional and digestibility changes in sprouted barley and canola seeds

Barley and canola seeds were sprouted over a 5 day period, in laboratory conditions under room temperature (22°C) and room lighting. Following initial hydration, seeds were kept moist by wetting the germination trays at 9 a.m., 1 p.m. and 6 p.m. daily. A parallel germination experiment using 200 g quantities of seeds in petri dishes was conducted. Starting from the second day of germination, and every day, dishes of germinating seeds were removed, oven-dried, weighed and milled for proximate and chemical analysis. Seeds from the main germination experiment were fed in a digestibility trial to Wistar rats. Results indicated that sprouting was associated with depletion of many nutrients in both barley and canola, the major losses being in respect of dry matter, gross energy and triglycerides. In barley (but not in canola) sprouting was associated with significant increases in crude fiber and diglyceride content. In canola, there were significant losses in lipid content and increases in phytosterol and phospholipid content. Digestibility data showed an enhancement in digestibility of nutrients in barley but not in canola, implying that sprouting improved nutritional quality of barley but not canola.

Variation in metabolizable energy content of raw or autoclaved white and brown varieties of three tropical grain legumes

White and brown varieties of three tropical grain legumes: pigeon pea, African yam bean and cowpea, were studied using soya bean meal as control. Raw or autoclaved (2.109 kg/cm2 for 30 min) samples of test legumes were analyzed for proximate constituents and evaluated for metabolizable energy with three-week-old Hubbard strain chicks. Test legumes were included at a 25% level of substitution in the diets. Metabolizable energy values differed (P < 0.05) between grain legumes, but there were no significant differences between white and brown varieties within legume species. Autoclaved varieties had significantly higher ME values than raw varieties. In all test grains, whether raw or autoclaved, the ME values obtained were higher (P < 0.05) than the ME value of the soya bean meal based control diet. It is presumed that autoclaving destroyed some anti-nutritional factors as well as increasing nutrient digestibility in the test grains.

Serum and liver lipids of rats fed rubber seed oil.

Crude rubber seed oil (RSO) was incorporated at the 5% level in diets free of cholesterol or containing 1% cholesterol, respectively. These studies were initiated for the purpose of evaluating the palatability and potential toxicity of RSO. Corn oil was used as a control. A considerable amount of unsaponifiable matter was detected in RSO. In addition, RSO was found to possess a fatty acid profile which was fairly different from that of corn oil, primarily due to a much higher content of linolenic acid and a lower content of linoleic acid in RSO. No adverse effects on food intake and average daily gain were observed in rats fed RSO in both cholesterol-free and cholesterol diets. The presence of RSO in cholesterol-free diets results in lower (p<0.05) serum and liver total cholesterol levels than in control animals. A relative hypercholesterolemic effect compared to corn oil was observed however, when RSO was added to diets containing 1% cholesterol. In summary, the physicochemical properties of RSO as well as the presence of cholesterol in the diet are important factors in evaluating the cholesterolemic effect of RSO.

Composition of nutrients in the sclerotium of the mushroomPleurotus tuber regium

A tuberous sclerotium of the mushroomPleurotus tuber regium was analysed for proximate, amino acid and mineral content. The sclerotium had low protein, ether extract, amino acid and mineral content compared to the pileus of the same mushroom and similar mushrooms. Cystine, methionine, serine, arginine and lysine were exceptionally low. Because the sclerotium is milled with melon seeds in traditional preparation of a vegetable meat-substitute, nutrient intake of a human subject consuming 100 grams of the meat-substitute was compared to intake of one consuming 100 grams of stewed broiler meat. The meat-substitute provided more minerals than broiler meat but only a fraction (40–65%) of the amino acids of broiler meat.

Growth parameters and plasma-tissue fatty acid profiles of rats fed rubber seed oil

Abstract Rats fed rubber seed oil (RSO) at the 10% level grew significantly less than those fed RSO at the 5% level or corn oil (CO) at the 5% or 10% levels, these rats showing disproportionately lower liver weights. There was no incidence of fatty liver due to oil source or dietary level. Similarly, no adverse effects were observed in levels of haematocrit, serum glucose and serum α-amino nitrogen in all rats fed RSO or CO. Fatty acid profiles of plasma and liver of RSO- or CO-fed rats were normal, although RSO-fed rats had significantly elevated levels of linolenic acid.

A comparison of metabolizable energy content of eight common feed ingredients determined with young guinea fowls (keets) and pullet chicks

Abstract Apparent metabolizable energy content (AME) of maize, soya bean meal, groundnut cake, cottonseed meal, dried brewers yeast, palm kernel meal, brewers spent grains and wheat bran were determined using three-week-old guinea fowls and three-week-old pullet chicks. The AME values for maize, soya bean meal, groundnut cake, dried brewers yeast, palm kernel meal and brewers spent grains were similar for guinea fowls and pullet chicks. Significantly higher AME values were observed with guinea fowls for cottonseed meal and wheat bran.

Effect of blending dietary oils on growth performance, total and individual fatty acid absorption by the growth chick

Abstract Canbra oil (6.1% erucic acid) was blended with sunflower oil or lard in the ratio of 1:1 (w/w). Canola oil (0.55% erucic acid) was blended with sunflower oil in ratios of 9:1, 8:2, 7:3, 6:4 and 5:5 (w/w). Influence of blending of dietary oils on growth performance, digestibility of total lipids and absorbability of individual fatty acids was studied using growing chicks fed lipids at 8% in practical diets. Results indicate significant differences (P

Fluted pumpkin (Telfaria occidentalis Hook.)

The fluted pumpkin, Telfaria occidentalis (Hook), is a tropical cucurbit, a member of a large family, the Cucurbitaceae, which includes gourds, pumpkins, squashes and melons. The botany of the crop has been described by Okoli and Mgbeogu (1983). The fluted pumpkin is a fast-growing, climbing annual which bears heavy fruits that are fluted or furrowed. The creeping stem may bear two or more fruits. Fruits take 5 months to mature and may weigh up to 10 kg. Small fruits weigh 2–5 kg. Fruits contain many seeds, small fruits containing up to 30 seeds, large fruits up to 70 seeds and very large fruits contain up to 100 seeds. Okoli and Mgbeogu (1983) report fruits measuring 105 cm in length and containing 196 seeds. They observe that the seeds are dark red in colour, non-endospermic and quite large in size, measuring 3.3–4.9 cm from end to end. Estimates of seed yield of fluted pumpkin in southern Nigeria are 2.5–3 tonnes/ha (Nwokolo and Sim, 1987). Seeds are cooked and eaten when mature. The young leaves form a very delicious vegetable when cooked, and are eaten in a variety of dishes.