Extraction and quantification of some valuable flavonoids from pinecone of Pinus brutia via Soxhlet and Supercritical CO(2) extraction: a comparison study

In this study, the extraction of oil from pinecone of Pinus brutia was evaluated by supercritical CO(2) (Sc-CO(2)) and Soxhlet extraction methods. The quercetin, rutin and kaempferol (QRK) contents of oil were analyzed one by one via HPLC. The rutin compound investigated in this study has the potential to be a drug against the COVID 19 virus. SEM and BET analysis were performed to observe the structural change and increase in surface area after Sc-CO(2) extraction. The operating conditions were investigated in the range of 35–65 °C temperatures, 140–220 bar of pressures, 0.30–1.00 mm of mean particle sizes, 3–7 l/min of CO(2) flow rates, 0–8% w/w co-solvent and 30–150 min extraction periods. When the results obtained by the Sc-CO(2) method were compared with the results of Soxhlet extraction method, the maximum recovery of total QRK was found 4.18% in co-solvent-free studies and 30.94% in co-solvent-added Sc-CO(2) studies. Sc-CO(2) extraction results of Q, R, and K were found as 14.75 ± 1.08 µg/g, 14.23 ± 1.27 µg/g, and 15.70 ± 1.13 µg/g pinecone, respectively. Soxhlet extraction results of Q, R, and K were found as 36.43 ± 2.26 μg/g, 57.19 ± 3.81 μg/g, and 50.80 ± 2.79 μg/g pinecone, respectively. The maximum amount of QRK was found as 44.68 ± 2.89 μg/g pinecone by Sc-CO(2) method via adding 8% ethanol by mass and as 144.42 ± 5.39 μg/g pinecone by Soxhlet method. According to the reference Soxhlet method efficiency, the Sc-CO(2) extraction recovery was found as 30.94%. GRAPHIC ABSTRACT: [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11696-021-01644-5.