Effect of flow rate on the extraction of volatile concentrates and resinoid compounds from origanum vulgare l. ssp. virens (hoffm. et link) letswaart using compressed CO₂

The effect of CO₂ flow rate on the extraction of the volatile concentrate and resinoid compounds from Origanum vulgare L. ssp. virens (Hoffm. et Link) letswaart was studied at liquid (300 K, 70 bar) and supercritical (310 K, 100 bar) conditions. The mass flow rate of CO₂ was varied between 0.3 kg/h to 0.9 kg/h with 0.2 kg/h increments. The degree and rate of extraction of the volatile concentrate was little dependent on CO₂ flow rate and was controlled by intraparticle resistances. An extract slightly richer in volatile concentrate was collected at liquid CO₂ conditions. The extraction of the resinoid compounds was mostly dependent on the flow rate of CO₂ and was limited by their solubility in compressed CO₂.