Physicochemical properties, chemical constituents, and antioxidant activity of Eurya honey

Abstract

Eurya honey (EH) is produced from the nectar of Eurya. In this paper, the physicochemical properties (moisture, free acidity, pH, 5-hydroxymethylfurfural, conductivity, sugar, and colour) of EH were systematically studied for the first time. The total phenols and flavonoids were determined by spectrophotometry, and the contents were 40.29 AE 4.17 mg GAE/100 g and 12.44 AE 0.62 mg RE/100 g, respectively. A total of 232 compounds were identified, and 30 of them were quantified by ultra-performance liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry (UPLC-Q/TOF-MS). The potential markers of EH were abscisic acid (21.3-103.4 μg/100 g), gallic acid (6.9-220.2 μg/100 g), tricoumaroyl spermidine (284.2-518.1 μg/100 g), and kaempferol (15.0-258.7 μg/100 g). EH showed antioxidant capacities in DPPH free radical-scavenging activity (IC 50 : 42.87-131.26 mg mL −1 ), ferric reducing antioxidant capacity (23.22-112.24 μmol FeSO 4 Á7H 2 O/100 g), and ABTS radical-scavenging activity assays (9.51-31.21 μmol Trolox/100 g).