Drying characteristics and moisture isotherms of hulless oats, Avena sativa L.
Hulasare, Rajshekhar Bhimashankar
A vertical-type thin-layer drier was used to obtain the thin-layer drying and rewetting data of hulless oats (Avena sativa L., cv. 'AC Belmont'). The experimental data were obtained by drying or rewetting 70% hulless oats in the thin-layer drier using air at constant relative humidity conditions. The data were collected for various combinations of initial grain moisture content (11 to 22% dry basis), temperature (15 to 36$\sp\circ$C), and relative humidity (27 to 93%). Thin-layer drying or rewetting data were analyzed using liquid diffusion, Lewis' and Page's equations. The liquid diffusion equation for an isotropic and homog neous sphere did not describe the drying and rewetting rate of oats satisfactorily. The thin-layer drying and rewetting rates at constant relative humidities agreed well with the Page's equation. The effects of temperature, relative humidity, initial moisture content and air velocities were investigated on parameters k and n of Page's equation. The temperature, relative humidity, and initial moisture content had significant effect (p $>$ 0.05) on k. The relative humidity and initial moisture content had significant effect on parameter n. The air velocity did not have significant effect (p $>$ 0.05) on drying or rewetting rate. Due to the nonlinear distribution of k and n among experimental tests, it was not possible to correlate k or n in terms of temperature and relative humidity for all the experimental tests. (Abstract shortened by UMI.)