Comprehensive Study of Mediterranean (Croatian) Propolis Peculiarity: Headspace,Volatiles, Anti‐Varroa‐Treatment Residue,Phenolics, and Antioxidant Properties |
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Authors: | Igor Jerkovi? Zvonimir Marijanovi? Piotr M Ku? Carlo I G Tuberoso |
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Institution: | 1. Department of Organic Chemistry, Faculty of Chemistry and Technology, University of Split, N. Tesle 10/V, HR‐21000 Split;2. Department of Food Technology, Marko Maruli? Polytechnic in Knin, Petra Kre?imira IV 30, HR‐22300 Knin;3. Department of Pharmacognosy, Wroc?aw Medical University, ul. Borowska 211a, PL‐50‐556 Wroc?aw;4. Department of Life and Environmental Sciences, University of Cagliari, via Ospedale 72, IT‐09124 Cagliari, (phone: +39‐070‐6758644;5. fax: +39‐070‐6758612) |
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Abstract: | Eight propolis samples from Croatia were analyzed in detail, to study the headspace, volatiles, anti‐Varroa‐treatment residue, phenolics, and antioxidant properties. The samples exhibited high qualitative/quantitative variability of the chemical profiles, total phenolic content (1,589.3–14,398.3 mg GAE (gallic acid equivalent)/l EtOH extract), and antioxidant activity (11.1–133.5 mmol Fe2+/l extract and 6.2–65.3 mmol TEAC (Trolox® equivalent antioxidant capacity)/l extract). The main phenolics quantified by HPLC‐DAD at 280 and 360 nm were vanillin, p‐coumaric acid, ferulic acid, chrysin, galangin, and caffeic acid phenethyl ester. The major compounds identified by headspace solid‐phase microextraction (HS‐SPME), simultaneous distillation extraction (SDE), and subsequent GC‐FID and GC/MS analyses were α‐eudesmol (up to 19.9%), β‐eudesmol (up to 12.6%), γ‐eudesmol (up to 10.5%), benzyl benzoate (up to 28.5%), and 4‐vinyl‐2‐methoxyphenol (up to 18.1%). Vanillin was determined as minor constituent by SDE/GC‐FID/MS and HPLC‐DAD. The identified acaricide residue thymol was ca. three times more abundant by HS‐SPME/GC‐FID/MS than by SDE/GC‐FID/MS and was not detected by HPLC‐DAD. |
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Keywords: | Propolis Croatia Headspace solid‐phase microextraction (HS‐SPME) GC/MS Analysis HPLC‐DAD Analysis Phenolics Volatiles Thymol acaricide residue Antioxidant activity DPPH FRAP |
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