BULK-DENSITY, POROSITY AND RESISTANCE TO AIR-FLOW OF GARLIC SLICES

The bulk density of garlic slices at different moisture levels (rangin g from approximately 3 to 65% MC wet basis) was determined by weighing the contents of a container of known volume. The porosity was calcula ted using its relationship with bulk and apparent densities. An analys is of variance (ANOVA) revealed that bulk density and porosity. were a ffected significantly by moisture and slice thickness as well as the i nteraction of these variables. Bulk density varied in a positive linea r fashion with moisture and thickness while a negative linear correlat ion was found for the calculated bulk porosity. The linear model met t he adequacy criterion for characterising the behaviour of garlic. Usin g a laboratory unit, the vertical resistance to airflow through the pr oduct and the effect of moisture and slice thickness were investigated for an airflow rates of 0.09 to 1.2 m3/s-m2. A higher resistance to a irflow was noted for the wet product with the experimental data fittin g to Shedd's model when the airflow range was divided into two sub-flo w rates and to a modified Ergun's equation for the full range.