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

Red clover (Trifolium pratense L.) honey: volatiles chemical-profiling and unlocking antioxidant and anticorrosion capacity

Igor Jerkovi’c, Ani Radonić, Marina Kranjac, Marina Zekić, Zvonimir Marijanović, Senka Gudićc, and Maja Kliškić

^aDepartment of Organic Chemistry, Faculty of Chemistry and Technology, University of Split, N. Tesle 10/V, HR-21000 Split, Croatia

E-mail: igor@ktf-split.hr

Abstract: Headspace solid-phase micro-extraction (HS-SPME) and ultrasonic solvent extraction (USE) were used for red clover honey volatiles extraction. The extracts were analysed using gas chromatography and mass spectrometry (GC-MS). Lilac aldehyde isomers dominated in the headspace (individual range from 7.6 % to 21.4 %) followed by phenylacetaldehyde (10.1-31.2 %) and benzaldehyde (7.0-15.7 %). Higher aliphatic alcohols and hydrocarbons were the predominant constituents of the honey extracts. The honey and its extracts exhibited rather weak anti-radical activity (DPPH assay) and total antioxidant activity (FRAP assay). On the other hand, the honey’s inhibitive properties towards the corrosion of AA 2017A alloy in NaCl solution (potentiodynamic polarisation and potentiostatic pulse measurements) revealed the honey to be a very good anodic inhibitor (efficiency up to 76 %) while the honey extracts (USE) showed better inhibition efficacy.

Keywords: red clover ( Trifolium ‘pratense L.) honey – volatiles – antioxidant activity – anticorrosion activity

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2016-0016

Chemical Papers 70 (6) 726–736 (2016)