EXPERIMENTAL STUDY OF PHYSICAL PROPERTY CHANGES IN MONODORA MYRISTICA SEED DURING ROASTING
Kwino Danlami Ibi & Benjamin A. Iwan
Department of Agricultural and Bio – Environmental Engineering,
College of Agriculture, Jalingo, Taraba State
Email: kwinodanlami@gmail.com
ABSTRACT: Thermal processes have been reported to affect the properties of biomaterials including seeds. Monodora myristica seeds are usually roasted prior to shelling, milling and use. The changes in the physical properties of Monodora myristica seeds during roasting were investigated in this study. The specific objectives of the study were to roast Monodora myristica seeds at different temperature and time combinations, determine the effect of the roasting parameters on the physical and frictional properties. Roasting parameters which include the roasting temperature at three levels (140, 170 and 200 oC) and roasting time at four levels (2, 7, 12 and 17 min.) were employed resulting in a 3 x 4 factorial experiment. The study revealed that the roasting temperature had no significant effect (p>0.05) on the size, shape and volume of the seeds. However, the roasting time significantly affected (p<0.05) the width, arithmetic and geometric diameters, and the volume except the length and the thickness. The length ranged from 17.22 to 18.87 mm, 17.93 to 18.08 mm, and 17.74 to 18.64 mm as the temperature increased from 140 to 200 oC and the time increased from 2 to 17 min. while the thickness ranged from 11.30 to 12.17 mm, 11.73 to 11.98 mm and 11.76 to 12.00 mm. The roasting parameters significantly affected (p<0.05) the complex geometric properties except the sphericity and the specific surface area. The effect of the roasting parameters on the angle of repose and the static coefficient of friction were significant (p<0.05) and followed the same trend. The highest mean coefficient of static friction values of 0.58, 0.53, and 0.53 were recorded at the 200 oC and 17 min. roasting condition on plywood, plastic and aluminum surfaces, respectively.