Moisture Sorption Characteristics of Dehydrated in-shell African Walnut (Tetracarpidium conophorum)

Moisture sorption isotherms are useful thermodynamic tools for determining water interactions within food systems and providing information that can assist in optimizing food processing operations such as drying, mixing, packaging and storage, as well as to maximize retention of quality parameters such as colour, aroma, texture, and nutrient. Moisture sorption isotherm characteristics of African walnut were evaluated at three different temperatures (28, 33 and 38°C) and relative humidity range of 11.20 - 97.00 % using gravimetric method; five mathematical models (GAB, BET, Peleg, Smith and Ferro Fontan) were fitted into the experimental data. Sorption isotherms of the dehydrated walnut gave type II (S-shaped) isotherms according to BET classification. Temperature had significant effect on the equilibrium moisture content (EMC). A nonlinear regression analysis method was used to evaluate the constants of sorption models. The models were evaluated statistically by calculating coefficient of determination (R2), the mean relative percentage error (P) and the reduced chi-square (λ2). The BET model gave the best fit for the obtained data among the tested models with R2 value of 0.9892. Calculated monolayer moisture (Mo) content from BET ranged from 5.018 to 7.922% db for adsorption and 9.842 to 10.143% db for desorption respectively

Amino acid profile of four earthworms species from Nigeria

The amino acid profile of four species of earthworms from Nigeria namely Eudrilus eugeniae, Hyperiodrilus africanus, Alma millsoni and Libyodrilus violaceus were evaluated in this study. The amino acid analysis was conducted using the High Performance Liquid Chromatography (HPLC) specifically the Technichon TSM-1 (technosequential multisample) analyser for amino acid. Nine essential namely Lysine, Histidine, Arginine, Threonine, Valine, Methionine, Isoleucine, Leucine and Phebylalanine and eight non-essential amino acids namely Aspartic acid, Serine, Glutamic acid, Proline, Glycine, Alanine, Cystine and Tyrosine were recorded in this study. Cystine with a range of 0.64-0.80 g/100kg protein had the least concentration while Glutamic acid with a range of 11.50-13.22 g/100kg protein was the highest. Lysine and methionine, which were limiting amino acids in most feedstuffs, were present in all the earthworm species and ranges from 4.95-5.70 g/100g protein for lysine and 2.08-2.30 g/100g protein for methionin

Macromineral Profile of Four Species of Earthworm Hyperiodrilus africanus, Eudrilus eugeniae, Libyodrilus violaceus and Alma millsoni from Nigeria

The macro mineral profile of four Nigerian species of earthworm; Hyperiodrilus africanus, Eudrilus eugeniae, Libyodrilus violaceus and Alma millsoni was conducted. using the atomic absorption spectrophotometer. Five macro minerals calcium, magnesium, potassium, sodium and phosphorus were determined. Comparatively H. africanus recorded the highest mean Ca (0.494 ±0.038%) while A. millsoni recorded the lowest (0.318±0.034%). Hyperiodrilus africanus also recorded the highest mean Mg (0.154±0.015%) whereas L. violaceus recorded the lowest (0.118±0.017%). Alma millsoni recorded the highest mean K (0.045±0.003% ) whereas H. africanus recorded the lowest (0.027±0.002%). The highest mean Na (74.209±13.699 ppm) was recorded by A. millsoni while the lowest (19.813±2.087 ppm) was recorded by H. africanus. Also A. millsoni recorded the highest mean P (0.701±0.022%) while H.africanus recorded the lowest (0.456±0.034%). A significant difference was observed in the mean % Ca, % M g, % K, ppmNa and % P between the four species of earthworms (p<0.01). The study revealed that these five macro minerals which are requirements of animals w ere well represented and adequate in the earthworms. Therefore, the use of meal prepared from these species as mineral supplement in fish diets could be encouraged

Partial replacement of fish meal by earthworm meal (Libyodrilus violaceus) in diets for African catfish, Clarias gariepinus

A seven-week feeding trial was conducted to examine the possibility of replacing fish meal with earthworm meal in the diets of the African catfish, Clarias gariepinus fry. Fish meal protein was replaced by earthworm meal at 0% (D0); 15% (D15); 25% (D25); 35% (D35); and 50% (D50). The diets were isonitrogenous (54%) and fed thrice daily to triplicate groups of African catfish fry at 5% body weight. Diet had a significant effect on growth performance and feed utilization (p≤0.05). Final weight, weight gain, daily weight gain, and specific growth rate, were highest in fish fed diet D25. A similar pattern of growth was observed for length measurements. Fish fed diets exceeding 25% replacement of fish meal with earthworm meal had depressed growth. Feed conversion ratio was highest in fish fed D35. Mortality was not dependent on diet. It is concluded that fish meal can be substituted with earthworm meal up to 25% in the diet of C. gariepinus fry without adverse effects on growth and nutrient utilizatio

Effect of optimizing process variables on the quality characteristics of cassava-wheat composite bread

The optimisation of bread-making process can have a positive impact in ramping up the quality characteristics of cassava-wheat bread to&nbsp; that of whole wheat bread. In this study, a threevariable Box-Behnken design response surface methodology was employed to investigate and optimise independent variables namely cassava flour composition, water content and proofing time in relation to response variables namely dough yield, loaf specific volume and loaf protein of cassava-wheat-composite bread. The data from the experimental design were fitted into second-order regression models and their validity and reliability were confirmed by analysis of variance. Optimal cassava flour composition, water content and proofing time were derived as; 100 g/kg, 589 g/kg and 90 min, respectively. It was revealed that cassava flour composition had the most effect on the quality characteristics of cassava-wheat-composite bread. At constant cassava flour&nbsp; composition, increase in water content and proofing time had a positive effect on all the studied quality characteristics of cassava-wheat composite bread. Increase cassava flour composition regardless of proofing time and water content had a negative effect on loaf specific volume and protein. This study has provided bread-making conditions which can be utilised in enhancing the consumer acceptability of cassava-wheat composite bread. &nbsp

Herbicidan control of water hyacinth at Ere, Ogun State: implications for fish production

A brief account is given of a pilot demonstration of the chemical control of water hyacinth (Eichhornia crassipes) at Ere (a channel) in Nigeria using the herbicide glyphosphate. Results suggest that there was an increase in the nutrient content of the channel after herbicide application. This implied an upsurge of available food for fish and other aquatic organisms within the channel after the herbicide application. The decaying water hyacinth mass which sinks into the medium is likely to boost nutrient content, promoting the growth of fish and other aquatic animals. It is concluded that herbicidal control of water hyacinth is possible, especially under specialists' management with the conservation of fish and other non-target aquatic organisms alongside improved fish productio

Soil Contamination and Risk Assessments on Selected Dumpsites within the Basement Complex and Sedimentary Formations of Ogun State, South-western Nigeria

The concentrations of inorganic elements in soils of Saje, Ita-Oshin, Premier, and Oke-Diya dumpsites were determined using an X-Ray Fluorescence spectrometer to assess the soil quality through chronological changes with depths. A soil core sampler collects 56 samples at 20, 40, 60, and 80 cm depths. Saje showed high mean concentrations of Ca, K, Fe, Rb, and Ti at all depths, while Oke-Diya revealed high mean concentrations of Ca, K, Fe, Rb, Ti, Mn, Zn, V, Cr, and Ni at all depths. These concentrations were in a closed range suggesting a build-up of elements in the soil profiles. Oke-Diya had the highest pollution index, followed by Saje, and the contaminations were from anthropogenic and geologic sources. The mean concentrations of Fe, Zn, Ni, Mn, Ti, K, and Ca were high at all depths in Ita-Oshin, and in Premier, the mean concentrations of K and Fe were high at all depths. Premier had the lowest pollution index. Ita-Oshin and Premier enrichment factors showed geologic sources. Saje and Oke-Diya revealed unacceptable non-carcinogenic risks for adults and children, and Ita-Oshin and Premier recorded acceptable limits. Saje and Oke-Diya samples had high carcinogenic risks for adults due to Cr, Pb, and As. Elements Cr and As in Ita-Oshin, and Pb in Premier evinced unacceptable carcinogenic risks for adults. Saje, Oke-Diya, and Premier indicated unacceptable carcinogenic risks for children due to Cr. The study showed toxins build-up in the soil system, and the study areas are not suitable for growing crops and sinking water wells for agricultural and domestic uses

Delineation of Leachate Plume Migration Using Electrical Resistivity Imaging on Lapite Dumpsite in Ibadan, Southwestern Nigeria

A geophysical investigation involving 2D resistivity survey was carried out on Lapite dump site that has been in operation since 1998 in ancient city of Ibadan, Southwestern Nigeria. The aim was to map the conductive leachate plume and extent of migration of leachate plumes in the subsurface for possible groundwater contamination. The 2D resistivity survey was carried out using Campus Tigre model resistivity meter with Wenner array configuration of electrode spacing distance ranging from 5 - 25m. A total of nine (9) 2D resistivity profiles with length ranging between 80 and 120 m were conducted within the dump site. A control profile of 2D resistivity survey was also carried out at about 300 m away from the dump site. The obtained resistivity data was interpreted using both RES2DINV and RES3DINV respectively. The 2D and 3D inverse resistivity models of the subsurface revealed the extent of leachate plumes with resistivity values less than 10 Ωm and allowed the location of leachate, clay soil, bedrock and seepage path from the dumpsite to be clearly delineated. There may be possible contamination of shallow groundwater system in the nearest future if proper mitigation measures are not taken into consideration at the dumpsit

Assessment of groundwater contamination around active dumpsite in Ibadan southwestern Nigeria using integrated electrical resistivity and hydrochemical methods

Investigation of groundwater contamination due to leachate migration in a solid waste disposal site was done using both geophysical and hydrochemical methods. The main goals were to delineate groundwater contamination due to leachate percolation and thus assessment of quality of groundwater from nearby hand-dug wells bordering the dumpsite for drinking purpose. A total of ten resistivity traverses were acquired within and outside the dumpsite using Wenner configuration with constant electrode separation ranging from 5 to 25 m. The 2D resistivity data were processed and inverted using RES2DINV and RES3DINV softwares, respectively. Geochemical assessment of groundwater samples were carried out according to APHA standards while hydrochemical facies of the sampled groundwater was evaluated using Piper Trilinear software. The inverse resistivity models of the subsurface from 2D and 3D imaging revealed low resistivity value less than 10 X m suspected to be leachate while 3D inverse sections allowed delineation of leachate, weathered layer, bedrock and seepage path from the dumpsite. The extent of migration was more pronounced in the southern part of the dumpsite, hence possible contamination of shallow groundwater system as dumpsite ages. The results of physico-chemical analyses showed the groundwater samples to be within the limits of WHO/NSDWQ for drinking purpose. However, higher values of concentrations of most analyzed parameters were noticed in well 1 due to its nearness to dumpsite and well 10 due to agricultural activities, respectively. Interpretation of Piper diagram showed CaHCO3 to be dominant facie in the area while alkaline earth metals (Ca2þ; Mg2þ) and weak acids (HCO3 -, CO3-) are dominant cations and anions during both climatic seasons. Groundwater in the study area is of hard, fresh and alkaline in natur

Process development for manufacturing of cellular structures with controlled geometry and properties

This study presents experimental results on the behaviour of aluminium alloy metal structures and foams manufactured by lost-wax casting and using 3D printed components for internal structure definition. Results for tensile tests, metallurgical properties, surface quality and geometry tolerances were obtained and discussed. The analysis focused on development geometries, used for adjusting manufacturing parameters and prototype geometries intended for geometrical and mechanical validation. The results are indicative of the viability of the method for producing foam structures suitable for mechanical loading.The authors are grateful to the Portuguese Foundation for Science and Technology (FCT) who financially supported this work, through the project PTDC/EME-PME/115668/2009.info:eu-repo/semantics/publishedVersio