15D-18 |
Correlating the solubility behavior of vegetable oils in supercritical carbon dioxide |
Ö. GÜÇLÜ-ÜSTÜNDAG and F. Temelli. Department of Agricultural Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2P5, Canada
The design of supercritical fluid processes involving fats and oils requires knowledge of solubility behavior. Binary systems provide fundamental yet limited information as deviations are observed in multicomponent mixtures. Although extraction of vegetable oils has been studied extensively, a systematic study investigating the solubility behavior of oils in supercritical carbon dioxide (SCCO2) has not been carried out. Our objective was to correlate literature solubility data of vegetable oils and the corresponding major triglycerides in SCCO2 to determine the general trends of solubility behavior of vegetable oils in relation to binary systems.
Solubility data of vegetable oils (rapeseed, soybean, palm kernel and palm oils) and triglycerides (lauric, palmitic and oleic acids) were correlated using Chrastils and del Valle and Aguilera equations as a function of CO2 density and temperature. Solubilities of oils were compared with each other and with binary solubility data for corresponding triglycerides to identify any associated trends. Model parameters were estimated for each oil and triglyceride. Association constant (k) was in the range of 8.86-10.75 and 10.46-11.49 for oils and triglycerides, respectively. Del Valle and Aguilera equation did not improve the correlation. The solubility behavior of vegetable oils could be related to that of triglycerides. Trilaurin was the most soluble triglyceride within the range of conditions studied. Thus, palm kernel oil had higher solubility in SCCO2 than palm oil. Although trilaurin was more soluble than palm kernel oil, triolein had lower solubility than soybean and rapeseed oils at 323 and 333 K. The information obtained in this study provides a basis for the study of complex multicomponent mixtures. The model parameters obtained can provide preliminary information about the solubility levels and trends of vegetable oils in relation to those of triglycerides. Findings are of significance for development of supercritical processes involving extraction, fractionation and reactions of lipids.
Session 15D, Food Engineering: Processing Technologies
|