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 af fected significantly by moisture and slice thickness as well as the in teraction of these variables. Bulk density varied in a positive linear fashion with moisture and thickness while a negative linear correlati on was found for the calculated bulk porosity. The linear model met th e adequacy criterion for characterising the behaviour of garlic. Using a laboratory unit, the vertical resistance to airflow through the pro duct 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 ai rflow was noted for the wet product with the experimental data fitting to Shedd's model when the airflow range was divided into two sub-flow rates and to a modified Ergun's equation for die full range.