An investigation of the volatile organic compound profiles and their sustainable extraction from Acacia dealbata tissues

The Australian native plant, Acacia dealbata , is prized for its fragrance, yet a comprehensive chemical analysis of its tissues and the efficacy of sustainable extraction methods remain under-explored. This study evaluated the volatile organic compound (VOC) profiles of different tissues from Australian Acacia dealbata . Absolutes (concentrated fragrance extracts) were extracted from flower and leaf tissue using conventional and green techniques, and the VOC profiles of both were compared with commercial absolute samples using headspace GC-MS analysis. A. dealbata flower and leaf extracts showed rich VOC profiles, thus proved suitable for the extraction of absolutes, while bark and seed contained few VOCs. Among the flower absolutes, green absolutes extracted using vegetable oils (sunflower, canola, and olive oil) gave higher extraction yields and more complex VOC profiles than a conventional absolute using n-heptane. Commercial absolute samples showed higher number of aroma compounds identified, however these samples show evidence of significant adulteration. The major VOCs in A. dealbata flower and flower absolute extracts were alcohols including isopropyl alcohol and methyl-butanol, esters including ethyl acetate and ethyl benzoate, aldehydes including 2-methyl propanal and 2-methyl butanal, and organic acids including acetic acid and propanoic acid. Leaf and leaf absolute mainly contained ketones including 2-pentanone and 3-pentanone, alcohols including 1-penten-3-ol, 2-hexen-1-ol and isopropyl alcohol, aldehydes including pentanal and 2-methyl propanal, and organic acids including acetic acid and formic acid. This research establishes a definitive VOC fingerprint for authenticating A. dealbata absolutes and validates vegetable oil-based green extraction as a scalable alternative for the foods, cosmetics, and fragrance industries. • Comprehensive VOC analysis of Acacia dealbata tissues identified flowers and leaves as rich sources for absolute extraction. • Vegetable oil-based green extraction yielded higher VOC diversity and extraction efficiency than conventional petroleum solvent-based extraction. • VOC fingerprinting enabled authentication of A. dealbata absolutes for applications in foods, cosmetics, and fragrances.