Oak (Quercus frainetto Ten.) honeydew honey--approach to screening of volatile organic composition and antioxidant capacity (DPPH and FRAP assay).
Two samples of oak honeydew honey were investigated. Headspace solid-phase microextraction (HS-SPME) combined with GC and GC/MS enabled identification of the most volatile organic headspace compounds being dominated by terpenes(mainly cis- and trans-linalool oxides). The volatile and less-volatile organic composition of the samples was obtained by ultrasonic assisted extraction (USE) with two solvents (1:2 (v/v) pentane -diethyl ether mixture and dichloromethane) followed by GC and GC/MS analysis. Shikimic pathway derivatives are of particular interest with respect to the botanical origin of honey and the most abundant was phenylacetic acid (up to 16.4%). Antiradical activity (DPPH assay) of the honeydew samples was 4.5 and 5.1 mmol TEAC/kg. Ultrasonic solvent extracts showed several dozen times higher antiradical capacity in comparison to the honeydew. Antioxidant capacity (FRAP assay) of honeydew samples was 4.8 and 16.1 mmol Fe(2+)/kg, while the solvent mixture extracts showed antioxidant activity of 374.5 and 955.9 Fe(2+)/kg, respectively, and the dichloromethane extracts 127.3 and 101.5 mmol Fe(2+)/kg.
Jerković
Igor
I
Faculty of Chemistry and Technology, University of Split, N. Tesle 10/V, 21000 Split, Croatia. igor@ktf-split.hr
Marijanović
Zvonimir
Z
D000975:Antioxidants / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D006722:Honey / Q000032:analysis*; D052617:Solid Phase Microextraction / Q000379:methods; D012997:Solvents; D055549:Volatile Organic Compounds / Q000032:analysis*
D000975:Antioxidants; D012997:Solvents; D055549:Volatile Organic Compounds