A pioneering study on the recovery of valuable functional compounds from olive pomace by using supercritical carbon dioxide extraction: Comparison of perlite addition and drying

In this study, supercritical carbon dioxide (SC-CO2) extraction was applied to the mixture of two-phase olive pomace (OP) with perlite and to the dried OP in order to prevent the environmental hazards that may arise from the leachate. Chemical oxygen demand (COD) and electrical conductivity (EC) of the leaching black water were detected as 131200 +/- 21024 mg/L and 12300 +/- 500 mu S/cm, respectively, leading to toxicity. Total phenolic content (TPC) was determined in the raw OP and in the extracts OP to 11000 mu M TE in the extracts. The maximum extraction yield and TPC recovery values were obtained as 5.7 % and 3 %, respectively. Promising results were obtained on the recovery of phenolic substances and fatty acids (FAs). Main groups of the valuable compounds such as secoiridoids, flavonoids and phenolic alcohols were detected in the pomace as 400, 290 and 100 mg/kg, respectively, while their concentrations increased up to 16430, 7370 and 3280 mg/kg in the extracts.

Automated summary

Supercritical carbon dioxide (SC-CO2) extraction was used to extract valuable compounds from two-phase olive pomace (OP) mixed with perlite and the dried OP to avoid environmental hazards caused by leachate. The leaching black water had high chemical oxygen demand (COD) and electrical conductivity (EC), resulting in toxicity. The TPC in the extracts reached 11000 μM TE, while the maximum extraction yield and TPC recovery were 5.7% and 3%, respectively. The concentrations of secoiridoids, flavonoids, and phenolic alcohols in the pomace increased significantly in the extracts.