Performance evaluation and optimization of a Moringa Oleifera depodding machine: A response surface approach

Depodding of moringa which is still being carried out manually by removing with hand or by hitting a bagcontaining the pods is time-consuming, labour intensive and not economical. The demand for quality oil-bearingmoringa seeds that have a wide area of industrial applications necessitates innovative deppoding techniques thatwill improve its market value. To ameliorate these problems, moringa depoddding machine has been developedbut studies on performance evaluation and optimal parameter setting are sparsely reported. This study therefore,evaluated the effects of the processing factors (moisture content (MC) and speed of rotation (SR)) levels on theperformance (throughput capacity (TP), effective throughput capacity (ETP), labour requirement (LR), depoddingcoefficient (DC), coefficient of wholeness (CW), depodding efficiency (DE), depodded kernel (DK), undepoddedkernel (UK), small broken kernel (SBK), and big broken kernel (BBK)) of the designed and fabricated moringadepodding machine using the response surface methodology and test between subjects-effects. The experimentaldesign used was a two factor, three levels i-optimal randomized design. Mathematical models relating the processfactors to performance were developed. The predicted optimum results obtained were validated using theobserved values of the experiment. MC and SR were found to have a significant effect on the performance of themachine. The predicted optimum performance of the machine were 113.73 kg/hr, 109.45 kg/hr, 0.85 man-hourrequired/Kg, 96.15 %, 0.96, 93.93 %, 0.98, 0.02, 10.64 %, and 1.24 % for TP, ETP, LR, DC, CW, DE, DK, UK, SBK,and BBK respectively at MC and SR of 10.10 % wet basis and 564 rpm. The experimental values at these pro-cessing conditions were close to the predicted optimum results obtained with little deviations which were sta-tistically insignificant. The selected models sufficiently predicted the performance of the developed machine

Wood Residues Generation from Sawmilling Activities and Energy Potential

The global concerns about the rise in anthropogenic gases have resulted in alternative clean energy sources. Biomass is one of the most prominent sources of renewable energy, which can be found in wood and wood wastes, agricultural crops and their waste byproducts, municipal solid waste (MSW), animal wastes, waste from food processing, aquatic plants and algae. Wood and wood wastes obtained from forest biomass stand at the centre of Renewable Energy Source (RES) due to its availability and usefulness in most developing countries. Sawdust is one of the wood processing residues that are in excess of local demand because of the near absence of its industrial demand in Kwara State. Data relating to its availability, industrial usage and energy potential are rarely available in this study area. This study investigates its availability and inherent energy potential that can be a vital tool for energy policy, planning and development. Wood wastes generated in the state were estimated to be 8012.8 m3 /yr with inherent energy potential of 31298 GJ. By putting sawdust, seen as wastes in most wood processing plants, into efficient use will help reduce the competition for wood as a source of heat for cooking and heating

Energy potentials of wood residues

The global concerns about the rise in anthropogenic gases have resulted in alternative clean energy sources. Biomass is one of the most prominent sources of renewable energy, which can be found in wood and wood wastes, agricultural crops and their waste byproducts, municipal solid waste (MSW), animal wastes, waste from food processing, aquatic plants and algae. Wood and wood wastes obtained from forest biomass stand at the centre of Renewable Energy Source (RES) due to its availability and usefulness in most developing countries. Sawdust is one of the wood processing residues that are in excess of local demand because of the near absence of its industrial demand in Kwara State. Data relating to its availability, industrial usage, and energy potential are rarely available in this study area. This study investigates its availability and inherent energy potential that can be a vital tool for energy policy, planning, and development. Wood wastes generated in the state were estimated to be 8012.8 m3 /yr with inherent energy potential of 31298 GJ. By putting sawdust, seen as wastes in most wood processing plants, into efficient use will help reduce the competition for wood as a source of heat for cooking and heating

Evaluating the Drying Characteristics of Paddy Rice Using Superheated Steam Dryer

It has been recorded in literature that superheated steam has the ability to combine the parboiling operation (steaming and drying) of paddy (Oryza sativa - UPL1) rice into a single unit. According to literature, this process has not been fully explored and implemented in rice processing. In this research work, superheated steam dryer was used to parboil (steam and dry) paddy rice. Soaking time and temperature used was 12hours at 60o C, with steaming time ranging from 10 to 24mins, while the drying conditions used were; temperature (160, 170 and 180o C), bed depth (1, 3 and 5cm) and tempering time (20 and 40 minutes). In addition, paddy rice was dried from initial moisture content ranging from 26-43% (d.b) to a final moisture content of 2 – 8% (d.b). It was observed that the milled rice yield ranged from 71.32 to 94.5%, head rice yield ranged from 70.5 and 90.6%, broken rice ranged from 3.2 to 7.7%, chalkiness ranged from 3.4 to 10.6% and drying capacity ranged from 0.1 to 0.36kg/h. The results obtained shows that drying with superheated steam can be used to improve rice qualit

DEVELOPMENT OF A LOCUST BEAN SEED DEHULLING CUM WASHING MACHINE

A wet locust bean seeds (Parkia biglobosa) dehulling and washing machine was developed to reduce the drudgery attached to traditional dehulling of the seeds which are processed for use as condiments and flavors’ for food in many African countries. The machine consisted of dehulling and washing units, the dehulling mechanism obtains its drive from a 0.38 kW gear motor of 30 - 50 rpm. The dehulling shaft; has rods arranged concentrically to break seed coat and radial fan-like blades used as a stirrer. The dehuller cum washer was evaluated based on the boiling time of the seeds on an electric cooker. The result indicated that the efficiency of the machine increased linearly with an increase in boiling time. The throughput capacity decreased with an increase in boiling time and moisture content decreased with an increase in boiling time from the sixth hour. Dehulling efficiency ranged from 59.7 to 68%, and cleaning efficiency ranged from 83.4 to 87.4 % while the average throughput capacity was 108 kg/hr

DEVELOPMENT OF AN IMPROVED GARI FRYER

Traditional frying of cassava mash into gari continues to be an onerous and complex unit operation for food processors. It is highly labor intensive, tedious, unhygienic and low productivity compared with the time and labor invested. The aim of this study was to design, develop a gari fryer, and evaluate its performance efficiency as affected by the mash moisture content. Cassava mash of different moisture contents (44.12, 45, 46.99, 48.99, 50.31, and 54.94 %) were fried, and the performance characteristics including, roasting time, percentage material loss, throughput capacity, and functional efficiency were evaluated. Results obtained indicated that frying cassava mash at 44.12 % wb moisture content produced the best frying condition, as it had the least material loss and frying time of 25 % and 1.17 hr, best throughput capacity and functional efficiency of 6.6 kg/hr and 75 %. The fabricated gari frying does not require technical expertise and can effectively address the challenges associated with traditional gari frying

Drying Characteristics, Kinetic Modeling, Energy and Exergy Analyses of Water Yam (Dioscorea alata) in a Hot Air Dryer

In this study, drying characteristics, kinetic modelling, energy and exergy analyses of a convective hot air dryer are presented for water yam. The drying experiments were carried out at temperature levels of 50, 60, and 70 ◦C and slice thicknesses of 3, 6, and 9 mm. The effects of drying variables on the drying rate (DR), moisture diffusivity (Deff), activation energy (Ea), energy utilization (EU), energy utilization ratio (EUR), exergy loss (EXL), exergy efficiency (EXeff), improvement potential (IP), and exergetic sustainability index (ESI) were investigated. The results showed that increasing air temperature increased the DR, Deff, EU, EUR, EXL, EXeff, IP, and ESI, while increasing the slice thickness increased Deff and Ea, but decreased the DR. The highest Deff and Ea values were 4.2 × 10−8 m2/s, and 53 KJ/mol, respectively. EU and EUR varied from 10 to 150 J/s and 0.39 to 0.79, respectively. EXL and EXeff varied between 2 and 12.5 J/s and 58 to 75%, respectively. Midilli’s model had the best performance in predicting the moisture ratio of water yam with coefficient of determination (R2 = 0.9998), root mean square error (RMSE = 0.0049), and sum of square error (SSE = 0.0023). Keywords: exergy efficiency; exergy sustainability index; water yam; drying rate; exergy los

Development and Process Optimization of a Ready-to-Eat Snack from Rice-Cowpea Composite by a Twin Extruder

A central composite rotatable design with four independent variables viz. blend ratio (broken rice flour and cowpea flour): 90:10–70:30, moisture content (10–18% wet basis), barrel temperature (110–150 ◦C), and screw speed (280–360 rpm) were varied in the development of ready-to-eat snacks using a twin extruder for a broken rice–cowpea product. The effects of the independent variables on specific mechanical energy, water absorption index, water solubility index, total color, hardness, bulk density, expansion ratio, and overall acceptability of the extruded snack were investigated using regression analysis. The results showed that the physical qualities of the ready-to-eat snacks were significantly affected by the extrusion parameters (i.e., blend ratio, barrel temperature, moisture content, and screw speed). From the findings, it was observed that screw speed and moisture contents affected hardness, while water absorption index was affected by all the extrusion parameters. However, the water solubility index and overall acceptance were majorly affected by the moisture content; extrudate produced with barrel ratio of 85:15, 12% moisture content, barrel temperature of 140 ◦C, and screw speed of 300 rpm was the most acceptable, at 6.73 on a 9 point hedonic scales. The blend ratio and barrel temperature influenced the expansion. Furthermore, the combination of cowpea and broken rice to produce nutritious ready-to-eat snacks has high acceptability and is a promising panacea for food security. Keywords: broken rice; cowpea; extrusion; food security and ready-to-eat snack