Gbenga Olatunde

Infrared Drying Characteristics of Long-Grain Hybrid, Long-Grain Pureline, and Medium-Grain Rice Cultivars

The objective for this study was to investigate the effectiveness of scaled-up infrared (IR) heating followed by tempering steps to dry freshly harvested rough rice. An industrial-type, pilot-scale, IR heating system designed to dry rough rice was used in this study. The heating zone of the equipment had catalytic IR emitters that provided heat energy to the sample as it was conveyed on a vibrating belt. The sample comprised freshly harvested rough rice of long-grain pureline (Cheniere), long-grain hybrid (6XP 756), and medium-grain (CL 271) cultivars at initial moisture contents of 23, 23.5, and 24% wb, respectively. Samples at a loading rate of 1.61 kg/m2 were heated with IR of radiation intensity 5.55 kW/m2 for 30, 50, 90, and 180 s followed by tempering at 60°C for 4 h, at a product-to-emitter-gap size of 450 mm, in one- and two-pass drying operations. Control samples were gently natural air dried in an equilibrium moisture content chamber set at relative humidity of 65% and temperature of 26°C to moi...

Assessment of New In-Bin Drying and Storage Technology for Soybean Seed

ABSTRACT On-farm, in-bin drying and storage of soybean in environments with unconditioned air often result in repeated drying and rewetting of the grains which may have adverse effects on quality metrics; if done using natural air, as recommended for soybean destined to the seed market, the in-bin drying and storage method require operation at well-defined local weather-dependent strategies to maintain the seed quality. This study simulated in-bin drying and storage of soybeans. Different fan control options and drying strategies were used to assess performance in terms of drying duration to target final moisture content (MC), percent over drying, energy expenditure, and drying cost. Fan operation included running the fan continuously, only at night, only during the day, at a set window of equilibrium MC (EMC) of natural air, and set EMC window with supplemental heating of ambient air as an option (EMC-H). Drying and storage performance were tested for soybean at initial moisture content (IMC) (16–22%, wet basis), air flow rate (1.04–5.0 m3 min−1 [air] t−1 [soybean]), and harvesting start dates (August 15 to November 15). Simulation model was validated using a bench-scale pressure drop system filled with soybeans with IMC of 22% wet basis. The result shows that fan control strategies, air flow rates, harvest date, and initial MC of the soybeans significantly (P < 0.05) impact the drying duration, percent over drying, and final MC of the grain. The simulation predicted well the overall profile of the experimental data. Layer by layer statistical comparison revealed that the overall mean relative deviation was less than 10%, low values of root mean square error (ranged between 2.4 and 2.5), Mallows’ criteria (ranged between 2.4 and 7.0), and overall χ2 was 0.88.

Impact of rewetting and drying of rough rice on predicted moisture content profiles during in-bin drying and storage

ABSTRACT Accurate prediction of moisture content (MC) is vital for effective control of on-farm, in-bin drying and storage of rough rice, especially for systems using recently introduced technology to automate fan run time. The study used simulations, laboratory, and field experiments to investigate the extent to which rewetting and drying, during in-bin drying and storage, affect accuracy of predicted MC—a critical parameter for automated fan control. Vapor sorption analysis (VSA) was used to generate MC prediction models for rough rice. Simulations of in-bin drying and storage, using in-field weather data, were performed while segregating effects resulting from rewetting and drying of the rough rice and the type of fan control strategy used. Predicted MC profiles of rough rice and drying durations were compared with those resulting from using standard constants in the literature for modeling. The root mean square error associated with predicting the MC by model constants developed using the VSA was 0.54% MC and 1.32% MC dry basis (d.b.), for desorption and adsorption, respectively. Deviation in MC logged by in-bin built, field sensors and that simulated by taking into account the influence of rewetting and drying were generally within 1.5% point difference. Therefore, rewetting and drying did not affect drying duration. However, drying duration was significantly influenced by fan control strategy (p < 0.05). It was concluded that under the same fan control strategy, the effect of rewetting and drying on predicted rough rice MC was negligible.

Emerging Pet Food Drying and Storage Strategies to Maintain Safety

Abstract The chapter presents main composition of pet food and primary sources, storage strategies to minimize loss of nutritious components, and advances of pet food drying and storage with a focus on emerging trends.

Engineering methods to reduce aflatoxin contamination of corn in on-farm bin drying and storage systems

ABSTRACT On-farm, in-bin drying of corn is weather dependent process that requires a careful selection of drying strategy in a locality to prevent reduction in the grain quality. This study simulated drying and storage of corn using different fan control methods and assessed the impact of infrared heat treatments to decontaminate corn of harmful molds spores. Fan operation considered included running the fan continuously, only at night (NANO), only during the day (NADO), at a set window of equilibrium moisture content of natural air, and when supplemented with heating of ambient air. The drying was investigated at various initial moisture contents (16 to 22%, wet basis), air flow rates (1.11 to 4.46 m3 min−1[air] t−1 [corn]) and corn harvesting start dates (August 15–November 15). To prevent aflatoxin contamination, freshly-harvested corn should be dried within 10 days to MC below 15% if prevailing relative humidity exceeds 86%.

Quality, Decontamination, and Energy Use Considerations During Radiant-Heat and Tempering Treatments of Shelled Corn

Infrared (IR) heating of corn followed by tempering treatments has potential to decontaminate corn of microbes without adverse effects on the overall corn quality. However, it is vital to determine the optimal processing parameters that maximize throughput and microbial load reduction and minimize drying energy without affecting overall corn quality. This study investigated effects of IR heating and tempering treatments on mold load reduction, corn color change, and drying energy requirements. Freshly harvested corn samples with initial moisture contents (IMCs) of 20, 24, and 28% wet basis were dried with a laboratory-scale IR batch dryer in one and two drying passes. The dried samples were then tempered for 2, 4, and 6 h at 50, 70, and 90°C. Results showed that mold load reduction ranged from 1 to 3.8 log colony forming units per gram of corn (log CFU/g) for one-pass treatments and from 0.8 to 4.4 log CFU/g for two-pass treatments as tempering temperature and tempering duration increased. Compared with t...