Background and objectives Polishing is a step of milling process to produce white rice. It influences rice quality. This study evaluates the effect of increased polishing duration (0, 1, 2, and 3 min) on the physical, milling, cooking, and sensory properties of novel mix‐colored Nigerian rice. These quality parameters influence the consumers’ choice. Findings Polishing duration had a significant effect on the physical, milling, cooking, and sensory properties of the milled rice. As the polishing duration increased, the length, width, length/width ratio, 1,000‐grain weight, bulk density, true density, porosity, optimum cooking time, cooking loss, aroma, and flavor of the milled rice reduced, while increased polishing duration increased the head rice yield, percentage broken rice, milled rice yield, percentage dockage, kernel elongation ratio, width expansion ratio, water uptake ratio, texture, appearance, and overall acceptability of the milled rice. The correlations between physical, milling, cooking, and sensory properties were strongly significant (p ˂ .01 and p ˂ 0.05). Conclusions This study revealed that increasing the polishing duration improves the cooking, head rice yield, milled rice yield, and some sensory quality attributes of the mix‐colored parboiled rice, but reduced its physical attributes. Significance and novelty The mix‐colored rice showed an improved milling, cooking, and sensory attributes but poor physical characteristics during polishing which is very vital to rice milling industry.

Most locust bean processing is still carried out locally in Africa. Dehulling is one of the major challenges encountered in traditional processing of locust bean seeds. Boiling time prior to dehulling is vital for nutritional status of locust bean. Hence, this study explored the influence of boiling duration before dehulling on the nutritional quality of mechanically dehulled locust bean seeds. The samples were subjected to four different boiling durations (1∼4 h) and the resulting effects on the overall acceptability, proximate composition, mineral content, and pH were evaluated. Locust beans boiled for 2 h and dehulled at the speed of 398 rpm gave the highest crude protein content, crude fiber, crude fat, and ash content. The pH ranged from 5.48 to 5.77, while boiling improved the mineral content ranging from 0.25∼0.48 mg/100 g (potassium), 16.80∼28.00 mg/100 g (calcium), 3.85∼6.73 mg/100 g (sodium), and 40.00∼52.40 mg/100 g (magnesium). The tedious labour during dehulling of locust bean seeds can be reduced at 398 rpm dehulling speed without adversely affecting the slightly acidic status and nutritional quality; thus enhancing quality and overall acceptability. Adoption of boiling raw locust bean seeds for 2 h under pressure prior to dehulling is a valuable procedure to eliminate long hours of boiling and tedious labour during local and industrial production.

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.