Characterization of extracts from wood waste of cembran pine (Pinus cembra L.)– chemical composition, antioxidant activity and antimicrobial potential

Wood residues of furniture production from cembran pine ( Pinus cembra L.) were used in supercritical CO ₂ extraction at high and medium extraction pressure. The Gas chromatography – mass spectrometry (GC/MS) analysis of extracts was performed, and the concentration of volatiles compared to the reference, commercially available (reference R) cembran pine oil. The reference sample had a much higher TVOC (Total Volatile Organic Compounds) content than the samples extracted with supercritical carbon dioxide (CO ₂ ). α-phellandrene, o-cymene and tricyclen were detected in the samples, extracted with the high (HP) and medium pressure (MP), with the highest TE (Toluene D8-Equivalents) value of o-cymene. To determine the antioxidant activity of the samples, DPPH (2,2-diphenyl-1-picrylhydratyl), ABTS (2, 2′-azino-bis(3- ethylbenzothiazoline-6-sulfonic) acid) and FRAP (ferric reducing antioxidant) assays were performed. In all three tests, our extracts showed stronger antioxidant activity than the reference, which showed significantly lower antioxidant activity, although the TVOC value was 75 times higher. The antimicrobial activity of the cembran pine extracts was determined as MIC (minimal inhibitory concentration) and MBC (minimal bacterial concentration) and MFC (minimal fungicidal concentration) values for Gram-positive, Gram-negative bacteria and fungi. The best antimicrobial activity was found in sample MP with the lowest achieved MICs followed by sample HP. For the sample R, the MIC could only be determined for C. albicans . Cembran pine wood waste extracts have shown good effect against C. jejuni intercellular signalling as well as against C. jejuni adhesion, indicating that cembran pine wood waste extracts have potential against complex bacterial properties that could be important for biofilm formation.