ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Extraction and quantification of some valuable flavonoids from pinecone of Pinus brutia via Soxhlet and Supercritical CO₂ extraction: a comparison study

Levent Nuralın, Metin Gürü, and Servet Çete

Department of Chemical Engineering, Engineering Faculty of Gazi University, Ankara, Turkey

E-mail: leventnuralin@gazi.edu.tr

Received: 20 February 2021  Accepted: 9 April 2021

Abstract:

In this study, the extraction of oil from pinecone of Pinus brutia was evaluated by supercritical CO₂ (Sc-CO₂) 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-CO₂ 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 CO₂ flow rates, 0–8% w/w co-solvent and 30–150 min extraction periods. When the results obtained by the Sc-CO₂ 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-CO₂ studies. Sc-CO₂ 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-CO₂ 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-CO₂ extraction recovery was found as 30.94%.

Graphic abstract

Keywords: Pinus brutia; Antioxidant; Rutin; Quercetin; Supercritical extraction; Soxhlet

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-021-01644-5

Chemical Papers 75 (10) 5363–5373 (2021)