An experimental storage based on the principle of evaporative cooling was designed to evaluate the performance of three natural absorbent fiber materials to be used as cooling pads. The absorbent materials were jute, hessian and cotton waste. The performance criteria included cooling efficiency, material performance and total amount of heat load removed from the evaporative cooler. The results showed that under the no-load condition, the average cooling efficiency was highest for jute at 86.2%, compared to 76.3% for cotton waste and 61.7% for hessian fiber. Materials performance tests results showed that the highest resistance to mold formation was exhibited by hessian followed by cotton waste, while the jute fiber had very poor performance. The heat load determination also showed that products stored in the cooler with jute as water absorbent produced the least heat of respiration, followed by cotton waste and hessian in that order. The total results indicated that jute had the overall advantage over the other materials. However, if the cotton waste surface could be modified to offer larger surface required for evaporation, it would be the best alternative because the jute surface is prone to mold formation.

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In cracking palm nuts by application of appropriate impact energy, one of the predominant factors that would enhance the release of either high percentage of whole or split kernels is the percentage level of moisture content in the nuts. The split kernels encourage rancidity of oil since the oily surface of the kernel is exposed to environmental influence. There is therefore need to study the absorption of water in dried palm nuts as a pointer to condition dried nuts to moisture content range that would enhance the production of whole kernels. In this study, dried Dura and Tenera palm nuts varieties were obtained from a palm oil processing mill, classified based on their minor diameter into three size ranges of small, medium and large sizes. These nuts were further dried to bone dry mass followed by immersion of each size range of nuts into different vessels containing water. The rate of water absorption was monitored at 3-hourly intervals. The data generated were analyzed. The result showed that the rate of water absorption per nut unit area had similar curves pattern as the drying curve established for palm nuts. Models for water absorption process involving the dried palm nut was developed based on basic underlying principles and data generated from experimental runs. The models were then validated; and found to be very useful in describing the water absorption process per nut unit area in a given time; and predicting moisture content of bone dry mass of nut soaked in water and kept at room temperature.

In an attempt to easily determine the desired moisture content at any time (t), of selected freshly harvested roots and tubers (yellow cassava, carrot, cocoyam and yam) of economic importance subjected to drying under unsteady temperature conditions such as sun drying, especially in the rural areas where there is no electricity or funds availability to acquire suitable drying equipment by local farmers; the drying constants based on established model that is anchored on mass of the material at any time t was carried out. In this study, three mass classifications, namely: small, medium and large were prepared for each material and subjected to oven drying at a given temperature till bone dry mass. The experimental values obtained were computed and graphs plotted to obtain the slopes as drying constants of values 0.3114, 0.1092, 0.3736 and 0.3790 for bulk samples of yellow cassava, carrot, cocoyam and yam respectively.

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The rotor of a palm nut cracker must be designed in such a way as to overcome friction, wears, the collision of nuts, etc. during nut cracking. Thus, there is a need to find the efficiency (rotor operating factor) Kf of the rotor and then used it to obtain the actual operating rotor speed in revolution per minute (rpm) for effective operation. In this study, masses of palm nuts (ḿ), its exit velocity from the rotor disc (v), rotor radius (r), axial dimensions, and energy generated due to friction, sound, heat, etc. (Ef), palm nut translational kinetic the energy (KEtrans), energy released per unit nut (Q) and inverse of theoretical rotor speed (Nt-1) were used based on some existing models. Plots of r against Nt-1 to determine the slope and thereafter evaluate Kf were carried out. The effect of ḿ on Kf was assessed using Analysis of Variance at 5% level probability. The results showed that the mean Kf was 0.76 and was not affected by varying ḿ since the calculated probability was 0.002 and r-squared was 0.324. The actual rotor speed could be found as the product of Kf and Nt.

Hibiscus sabdarrifa are cultivated and consumed as tea, whereas other hibiscus varieties are planted for the fibers they produce. Hibiscus sabdariffa known as roselle, is one of the underexploited food crops with nutritional and food industry processing potential. Thus, this study was undertaken to determine the effects of different drying methods (sun, solar and oven drying) and drying kinetics on the proximate composition of dried calyx (Proximate and Mineral composition) using AOAC Standard. The data obtained from this study was statistically analyzed using Tukey HSD (Tukey Honest Significant Difference). The values of the model constant and other Statistical parameters for moisture ratio were obtained. The two-term exponential model had the highest R2 and the lowest x2 and RMSE value. The model constants, the R2, x2 and RMSE for each model were obtained. The page model had the highest R2 and lowest x2 and RMSE and was selected as the best fit model for describing the drying kinetics zobo calyces in an oven dryer while Logarithmic model and Wang and Sing Model was selected for modeling of zobo calyces in sun and solar dryer respectively. The experimental and predicted moisture ratio values are very close to the each other given the R2 value and the straight-line graph when the predicted moisture ratio is plotted against the experimental moisture ratio. Sample dried with oven dryer gave the highest carotenoid and vitamin C content compared to other drying methods. Therefore, oven dryer is recommended for drying of zobo calyces as compared to sun and solar dryer.