Criteria for the Extraction of Fish Oil

The effect of pre-treatment of mackery (Scomber scombrus) on oil recovery and quality was investigated. Fish oil was extracted using the screw expeller press after heat pre-treatment of the fish sample. The effect of cooking temperatures and cooking times was evaluated. It was observed that the oil yield has a positive relationship with cooking temperature. The oil yield increased with increasing cooking temperature at all the cooking times investigated and also increased with increasing cooking time from 5-15 minutes and then decreased for 20 minutes cooking time at all the cooking temperatures investigated. The results revealed that a highest yield of 22.8 % was obtained when the fish was treated at 90 0C cooking temperature for 15 minutes. The lowest oil yield of 16.5 % was obtained for the conditions of 60 0C cooking temperature and 5 minutes cooking time. Analysis of oil quality indices (e.g. colour, specific gravity, refractive index, free fatty acid value, saponification value. iodine value, peroxide value, unsaponifiable matter and microbiological analysis) of oil extracted by non pre-treatment and heat pre-treatment indicated that mackery oil from both processes has comparatively similar fatty acids composition. In addition, mackery fish oil was extracted by heat pre-treatment and mechanical press had lower lipid oxidation compared to several standards

Engineering properties of acha (Digitaria exilis) grains in relation to the design of grain processing machines

Engineering properties are very important in the design and manufacturing of processing machines. In this research work, the engineering (physical, aerodynamic and mechanical) properties of acha (Digitaria exilis) grains were determined as design parameters for the development of grain processing machines for the crop. The physical properties determined were length, width, thickness, arithmetic mean diameter, geometric mean diameter, roundness, sphericity, aspect ratio, surface area, projected area, volume, moisture content, one thousand seed weight, bulk density, true density and porosity. The average seed length, width and thickness were found to be 1.84 ± 0.055, 0.85 ± 0.023 and 0.75 ± 0.042 mm respectively. The average arithmetic and geometric mean diameters were 1.15±0.014 and 1.05±0.018 mm respectively. The average roundness, sphericity and aspect ratio were 0.5840±0.011, 0.5732±0.013 and 0.4678±0.012 respectively. The mean surface area, projected area and volume were 3.49±0.25 mm2, 1.23±0.033 mm2 and 0.61±0.029 mm3 respectively. The average moisture content was 14.73±2.14% dry basis and the thousand kernel weight was 0.827±0.053 g. The average bulk and true densities were 1092.86 ± 24.13 and 1626.15 ± 62.91 kgm-3 respectively and the porosity was 32.52 ±1.34%. The aerodynamic properties determined in this study were terminal velocity, drag coefficient and Reynold's number. The average terminal velocity, drag coefficient and Reynold's number of the seeds were found to be 3.97 ± 0.015 m/s, 0.684 ± 0.062 and 311.37 ± 13.47 respectively. The mechanical properties determined in this study were angle of repose, coefficient of static friction, shear strength and compressive strength. The mean angle of repose was 32.50±1.36o while the mean coefficient of static friction on mild steel surface was 0.82±0.043. The mean shear strength and compressive strength of the seeds were 3840±72.32 and 7615±90.28 N/m2 respectively. These parameters would provide important and essential data for the efficient design of acha processing machines

Mathematical modeling of mechanical horizontal screw oil extractor

A theory using mechanical expression was proposed from the physics of oil expression in a screw press to characterize a mathematical model. The general oil expression equation was solved for three machine parameters (choke clearances, screw shaft clearances and screw shaft speeds) which simulate the machine parameters effects in the overall screw expeller process. The mathematical model was validated by the experimental data obtained from pressing fish oil with a screw press, using regression analysis. The experimental oil extraction data was fitted to the model and the quality of fit evaluated. A good fit was indicated by correlation coefficient of 0.9983, coefficient of determination of 0.9967, absolute average percentage deviation of 4.8 %, coefficient of variation of 3.4 % and chi-square goodness of fit of 1.8. Good agreement was obtained between experimental and predicted data. The optimum oil yield (22.5 %) is equal to the maximum oil yield (22.5 %) obtained in the experimental study. The mathematical model was also used to satisfactorily predict the performance of commercial screw expellers. This theory however provided an alternative to the costly and time-consuming empirical studies in obtaining information on the performance of a press

Effects of groundnut shells on soil properties, growth and yield of maize

The aim of the study was to assess the effects of groundnut shells on soil properties, growth and yield of maize. The study was carried out in Jalingo, Taraba State, North-Eastern Nigeria in July, 2019. Treatments in the study were four doses of groundnut shells (0.0, 2.5, 5.0 and 7.5 t ha-1); arranged in a randomized complete block design, replicated four times. Each plot was 2.0 m × 2.0 m with 0.5 m gap between the plots and replicates. Crushed groundnut shells were applied on a dry matter basis at the rates of 0, 2.5, 5.0 and 7.5 t ha-1 28 days before planting maize. Seeds were planted on prepared land treated with crushed groundnut shells. Soil properties were determined at harvest, maize growth parameters were determined at 50% flowering and maize yield parameters were determined at maturity. The results showed that groundnut shells application increased soil porosity, water holding capacity, soil pH, organic matter, nitrogen, phosphorus, calcium, magnesium, potassium, sodium and total exchangeable bases and decreased soil bulk density to favorable levels. Groundnut shells application also increased plant height, stem girth, number of leaves per plant, leave area, leave area index, cob length, number of seeds per cob, seed weight per plant, hundred (100) seed weight, stover yield, grain yield and harvest index and decreased number of days to 50% tasseling. The result suggests that the 7.5 t ha-1 of groundnut shell application rate be utilized, as a more appropriate and profitable groundnut shell incorporation method in order to achieve better performance of maize plants

Effect of Expeller Press Parameters on Fish Oil Extraction

An investigation was carried out on the effect of expeller press parameters such as choke clearances (1, 2 and 3 mm), screw clearances (1, 2 and 3 mm) and screw (worm) shaft speeds (50, 60 and 70 rpm) on fish oil extraction. The oil extraction rate and extraction efficiency had a negative relationship with choke clearances and screw clearances but had a positive relationship with screw (worm) shaft speeds. The oil extraction rate and extraction efficiency were found to decrease with increase in choke clearances and also decreased with increase in screw clearances. Increase in screw (worm) shaft speeds from 50 to 70 rpm was observed to increase oil extraction rate and extraction efficiency. The extraction loss had a positive relationship with choke clearances and screw clearances but had a negative relationship with screw (worm) shaft speeds. The extraction loss was found to increase with increase in choke clearances and also increased with increase in screw clearances. Increase in screw (worm) shaft speeds from 50 to 70 rpm was observed to decrease extraction loss. The results obtained from the study of the effects of expeller press parameters on fish oil extraction showed that choke clearance, screw clearance and screw speed influenced oil extraction significantly at 95 % confidence level. The best extraction condition was 1 mm choke clearance, 1mm screw clearance and 70 rpm screw speed, which gave oil extraction rate of 18.91 kg/hr, extraction efficiency of 83.96 % and extraction loss of 5.76 %. The results of this study are useful in optimising the design of presses for fish oil extraction

Production and evaluation of compost tea for cultivation of Amaranthus hybridus

The application of organic fertilizer to the soil is considered as good agricultural practice because it improves the fertility of the soil and plant quality. The aim of the study was to produce compost tea using poultry droppings, cow dungs and water leaf (Talinum triangulare) in a ratio 5:5:1 and evaluate its effects on soil properties, growth and yield of Amaranthus hybridus. The study was carried out in Jalingo, Taraba State, North-Eastern Nigeria in July, 2019. The experimental variables include control (no treatment), 1 kg of compost per 10 L of water compost tea, 1 kg of compost per 20 L of water compost tea, 1 kg of compost per 30 L of water compost tea, 500 kg ha-1solid compost and 500kg ha-1 NPK fertilizer. The treatment combinations were done in a randomized complete block design, replicated four times, giving a total of twenty four plots. Each plot was 2.0 m × 2.0 m with 0.5 m alley between the plots and replicates.  Soil properties were determined at harvest while growth and yield parameters of Amaranthus hybridus were determined at maturity. The results showed that compost tea, solid compost and NPK compound fertilizer application increased soil porosity, water holding capacity, soil pH, organic matter, nitrogen, phosphorus, calcium, magnesium, potassium, sodium and total exchangeable bases and decreased soil bulk density and particle density to favorable levels. Compost tea, solid compost and NPK compound fertilizer also increased plant height, stem girth, number of leaves per plant, leave area, leave area index, root yield, stem yield and leaves yield. The result showed that 1 kg of compost per 10 L of water compost tea produced tallest plants (118.18 cm) with largest stem girth (2.586 cm), highest number of leaves per plant (42.44), largest leave area (98.66 cm2), highest leave area index (4.606), highest fresh root yield (5.25 tons ha-1), highest fresh stem yield (30.12 tons ha-1) and highest leaves yield (18.22 tons ha-1). Compost tea elicited higher growth and yield characteristics of Amaranthus hybridus plants than solid compost, NPK compound fertilizer and control (no fertilizer) in decreasing order in the variety of amaranth used. The result suggests that the 1 kg of compost per 10 L of water compost tea application rate be utilized, as a more appropriate and profitable soil fertility enhancement method in order to achieve better performance of Amaranthus hybridus plants. This implies that compost tea extracts from poultry droppings, cow dungs and water leaf (Talinum triangulare) can be used in a sustainable agriculture to increase yield and quality of Amaranthus hybridus

Prediction of the productivity of floodplain soils in Taraba state using productivity models

A study was carried out to quantify the productivity level of floodplain soils in Taraba state using Neill’s Productivity Index (PI) and Modified Neill’s Productivity Index (PIM). Fields and laboratory experiments were conducted to study the effects of locations on distribution of bulk density, available water capacity, pH, organic matter, available phosphorus, iron oxide and aluminium oxide at different soil depths, and its effects on soil productivity. The bulk density and available water capacity were found to increase with soil depths while the soil pH, organic matter, available phosphorus, iron oxide and aluminium oxide were found to decrease with soil depths at all the locations investigated. The results show that soil productivity index was significantly (P ≤ 0.05) affected by locations of the floodplains