Mathematical modeling of supercritical CO2 extraction of hops (Humulus lupulus L.)

- Highest extraction yields were obtained at 200 bar and 55 °C.
- Major compound in the drop extract was lupulone.
- The kinetic data were simulated with equilibrium, broken and intact cells and shrinking core models.
- The microstructural factor was used to evaluate which model best represented the extraction.

The supercritical CO2 extraction of hop pellet (Humulus lupulus L.) was performed under different conditions of temperature and pressure. The yields obtained ranged from 1.2% (100 bar, 55 °C) to 7.1% (200 bar, 55 °C). The extracts were analyzed by GC-MS, and the most abundant compound was lupulone. Kinetic curves were simulated using the equilibrium, broken and intact cells (BIC) and shrinking core (adapted for slab-like particles) models with satisfactory adjustment on all three models, but with significant better results with BIC model. A correlation to estimate the operational solubility was obtained. Mass transfer parameters obtained were temperature and pressure dependent and were studied using the microstructural factor.

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