Effects of particle size distribution, moisture content, and initial oil content on the supercritical fluid extraction of paprika

This work is intended to determine what effects the characteristic particle size, moisture content and initial oil content have on the supercritical fluid extraction of paprika (Capsicum annuum L.).The extraction efficiency was defined as the yield obtained using supercritical carbon-dioxide divided by the yield obtained by Soxhlet-extraction with n-hexane.For describing the extraction efficiency curves the Sovová model was chosen.It was observed that a decrease in particle size resulted in an increase in extraction efficiency. The oil was easily removed from milled samples with characteristic particle sizes between 0.1 and 0.7 mm. Moisture content between 7 and 18% had negligible effect on extractability of oil. However, above 18% moisture level the presence of water affected the extraction, by increasing the moisture content the efficiency decreased. As for changing the oil content, different mixtures of seeds and fruit were investigated. In the range of 5–10% oil content a positive effect was found, while above these values an increase in the oil content has no significant effect on the efficiency of supercritical fluid extraction.