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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 60°C, with steaming time ranging from 10 to 24mins, while the drying conditions used were; temperature (160, 170 and 180°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 quality.

This research was carried out to determine the energy requisite in terms of the specific thermal energy consumption, the specific electrical energy consumption and the drying capacity of a superheated steam dryer. The superheated stream dryer consists of a boiler housing, steam transfer pipes made of galvanized steel, super-heater made up of two (2) heater bands of 4000W (used to convert saturated steam to superheated steam), superheated chamber made of galvanized steel, the drying chamber made using stainless steel, a PID temperature controller (for regulating the temperature of superheated steam) as well as a water heater of 1500W to raise the temperature of water to saturation temperature. The result observed revealed that, drying capacity ranged from 0.1 to 0.36 kg/h, specific thermal energy consumption ranged from 9.22 to 19.99 kJ/kg and specific electrical energy consumption ranged from 15.41 to 57.17kWh/kg as influenced by temperatures of 160-180 °C, bed depths of 1 to 5 cm and tempering time of 20 and 40 minutes. Results obtained proves that drying paddy rice in a superheated steam dryer in comparison with hot air dryer has lesser energy consumption and saves operational cost.

Drying is one of the major unit operation in food industry and it kinetics data is required for optimization. The aim of this study was to evaluate the effect of air temperature (50, 60, and 70°C), air velocity (0.5, 1, and 1.5 m/s), and slice thickness (3, 6, and 9 mm) on the moisture ratio of yam slice during drying. Ten (10) different empirical models were used in fitting the experimental moisture ratio data, the prediction performance was evaluated with sum of square error (SSE), coefficient of determination (R2) and root mean square error (RMSE). The model fitting shows that the Two term model was most performed based on R2, SSE, and RMSE value. This result can be use to control the drying systems for yam slice.

This study seeks to investigate the performance of maize cob and maize cob with stalk with a mix ratio 2:1; 200 g shelled maize cob: 100 g of maize stalk) briquettes as fuel source for domestic cooking. The two residues were individually chopped into small pieces using a hammer mill and 0.6 mm particle size was utilized for the purpose of this work. Cassava starch was used as binder with mix ratio of 2:1 (Residue to Binder). A briquetting mold was used and residues were compressed into briquettes using a manual hydraulic press. Performance tests showed maize cob with stalk briquettes performed better with a higher cooking efficiency (17.3 %), fuel efficiency (19.78 %) and low fuel consumption (0.97 kg/hr) and boiling time of 20 mins. These results were significant at 5 % level of significance. Maize cob briquettes had higher calorific value (17.8 MJ/Kg) and higher fuel consumption rate (1.3 kg/hr), but had lower cooking efficiency (10.28 %) and fuel efficiency (12.8 %) with a boiling time of 15 minutes. The smoke emission using the briquettes was highly reduced. The crop residues used significantly affect the performance of the developed briquettes. Maize cob with stalk briquette was preferred due to its high cooking efficiency, fuel efficiency and low fuel consumption.

Irrigation and mulching are important soil management practices for sustainable food productions. Different irrigation and mulching treatments could however affect soil hydrothermal properties and hence the soil productivity. This study evaluated the effect of drip irrigation interval and mulching type on selected hydrothermal properties of an Alfisol cropped with Cucumber (Cucumis sativus). A field experiment, laid out in a randomized complete block design (RCBD) with three replications, was conducted with split-plot arrangement having irrigation interval as the main-plot and mulching material as the sub-plot. Three irrigation intervals: two days per week (D2), four days per week (D4) and six days per week (D6); and two mulching materials: plastic (M1) and spear grass (Imperata cylindrica) (M2) were applied. There were nine (9) treatment combinations which gave a total of 27 plots. Soil physical properties of soil water content (SWC), bulk density (BD) and saturated hydraulic conductivity (Ksat) were monitored during the growing cycle. Thermal conductivity, resistivity, diffusivity and volumetric specific heat of the soil were measured. There was no significant difference in thermal conductivity, thermal resistivity, thermal diffusivity and volumetric specific heat, under the irrigation intervals. The cucumber yield under the mulch treatment was in the order of M1 > M2 > M3. The Cucumis sativus yield was highest under M1 and D4 (11629.63 kg/ha) and lowest in M3 and D2 (3362.22 kg/ha). The mulching treatment had significant effect on the soil temperature, SWC, BD and yield while the irrigation treatment had no significant effect on the soil properties considered.