Extraction rates of oil from high oleic sunflower seeds with supercritical carbon dioxide

Supercritical CO2 extraction of oleic sunflower seeds was shown to be effective and yielded a product very similar to pure refined oil. In our work extraction pressure was restricted to 250 bars, due to technical constraints, and for this pressure, a temperature increase (up to 60 degreesC) was observed to be detrimental. Grinded seeds were used, segregated into average small particles (0.25 mm), and average large particles (1.25 mm), the extractable oil content of the latter being smaller. In relation to particle size, differences in extraction rates and yields were observed. Modelling using conventional models was attempted and Sovova's model, which considers accessible and inaccessible oil content, appeared to be the most adequate. (C) 2002 Elsevier Science B.V. All rights reserved.