Effect of Temperature and Slice Size on Avocado Pulp Drying Rate and Oil Yield

Abstract

The effect of temperature and slice thickness on avocado pulp drying rate and oil yield was determined at 50 o C, 60 o C and 70 o C. Pulp slices of 2mm and 5 mm thick were used. The avocado pulp was found to contain 74-75% (wet basis) water, which makes extraction of oil by both chemical and mechanical means difficult. Experimental results showed that oil yield increased with decreasing moisture content reaching a yield of 61% at 10% moisture content. The rate of drying increased with temperature, but decreased with slice thickness. The drying data obtained agreed well with several thin-layer drying models. The models showed that the characteristic drying constant increased linearly with drying temperature and decreased with slice thickness. The Physico-chemical properties of the obtained oil compared favorably with those obtained from other conventional seed oils.