Application of Response Surface Methodology and Central Composite Rotatable Design for Optimization of Supercritical Fluid Extraction of Lipids from Date Pits

摘要

Tons of date pits are being produced every year in the United Arab Emirates as by products in the process of making date syrup and other related products. At present, date seeds have very limited use. Date seeds may have extractible high value-added components that are sensitive to high heat as is the case during steam distillation. Application of supercritical carbon dioxide may offer a unique opportunity to extract some of these compounds. Central Composite Rotatable Design (CCRD) and Response Surface methodology are used to optimize parameters for supercritical fluid extraction of lipids from date pits. The effects of pressure, temperature and CO_2 volume on the extraction yield of date pit oil have been investigated. The temperature tested ranged from 33 to 92°C (33, 40, 60, 80 and 92°C) while the pressure tested ranged from 132 to 468 bars (132, 200, 300, 400 and 468 bars). The volumes of CO_2 tested were 66, 100, 150, 200 and 234 ml. Results indicate that at any particular temperature, increasing the pressure will increase the yield. With respect to temperature, the effect depends on the pressure applied. Under low pressures, increasing the temperature tends to decrease the yield. However when the pressure is high the yield tends to increase with increasing temperature. Carbon dioxide volume showed positive effect within the range studied.