Recovery of bioactive compounds from cranberry pomace using ternary mixtures of CO2 + ethanol + water

- Polyphenols were recovered from cranberry pomace using high pressure CO2 + H2O + ethanol mixtures.
- The presence of water in the extraction solvent was critical to obtain high phenolic recoveries.
- At high CO2 levels, the presence of water was beneficial for high phenolic recoveries.
- Extraction of lipids first with SC-CO2 further improved polyphenol recovery in the subsequent step.
- Compared to a conventional solvent extraction, ethanol consumption could be drastically reduced.

Bioactive compounds were extracted from cranberry pomace using supercritical CO2 (SC-CO2) and ternary mixtures of CO2 + ethanol + water. Process temperature (40-60 °C) and pressure (30-50 MPa) exerted no significant effects on the amount of lipids extracted after 4 h using SC-CO2. Working in the two-phase region of the ternary mixtures yielded extracts with high total phenolic and anthocyanin contents and antioxidant activity. The presence of water in the solvent was essential for enhanced polyphenol recovery. Consecutive extraction of lipids and phenolics was conducted using SC-CO2 and ternary mixture, respectively. Compared to a conventional solid-liquid extraction with 70 vol% acidified aqueous ethanol, similar quantities of total phenolics and anthocyanins were extracted. Ethanol consumption was reduced by up to 88% compared to this conventional extraction method, showing the great potential of ternary compressed fluid extraction as a cost efficient and green technology for the extraction of bioactive compounds from plant residual material.

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