Characterisation of phenolic compounds in Algerian honeys by RP-HPLC coupled to electrospray time-of-flight mass spectrometry

•Several phenolic compounds have been identified in honey extracts.•Caffeic and p-coumaric acids are markers for Capparis and Trifolium honey, respectively.•All honey samples shared hydroxybenzoic acid and seven flavonoids aglycones.•Chromatograms of Erica honeys and some of Eucalyptus honeys showed similar profiles.•Algerian honeys contain antioxidants that may have biological activities.

A total of 35 honey samples from different regions of Algeria were studied to determine their phenolic profiles. Phenolic compounds, products of the secondary metabolism of plants, were extracted with amberlite XAD-4 and analysed by liquid chromatography, with diode array detection and electrospray ionisation mass spectrometry in negative ion polarity. By using colorometric assays, Erica honeys showed the highest content of phenolic compounds and flavonoids (245 ± 54 mg GAE/100 g and 29 ± 6 mg QE/100 g, respectively). More than 30 compounds were identified in the honey samples studied including 14 phenolic acids and 16 flavonoids. In general, honey samples showed different chromatographic profiles. It has been shown that 4-hydroxybenzoic acid, apigenin, chrysin, galangin, kaempferol, isorhamnetin, luteolin and pinocembrin were present in all honey extracts. Moreover, caffeic, p-coumaric and vanillic acids; abscisic and syringic acids; and benzoic acid were detected in 34, 33 and 32 honey samples, respectively. The members of flavonol subclass were the most abundant of the identified flavonoids. Gallic and homovanillic acids, daidzein and myricetin were less present: 7, 5, 7 and 6 in honey samples, respectively. Caffeic and p-coumaric acids were potential floral markers for Capparis spinosa and Trifoliumn honeys, respectively.