Screening of Polish Fir Honeydew Honey Using GC/MS, HPLC-DAD, and Physical-Chemical Parameters: Benzene Derivatives and Terpenes as Chemical Markers

Abstract

GC/MS of headspace solid phase micro extraction (HS-SPME) and solvent extractives along with targeted HPLC-DAD of Polish fir (Abies alba Mill.) honeydew honey (FHH), were used to determine the chemical profiles and potential markers of botanical origin. Additionally, typical physical-chemical parameters were also assigned. The values determined for FHH were: conductivity (1.2 mS/cm), water content (16.7 g/100 g), pH (4.5), and CIE chromaticity coordinates (L* = 48.4, a* = 20.6, b* = 69.7, C* = 72.9, and h° = 73.5). FHH contained moderate-high total phenolic content (533.2 mg GAE/kg) and antioxidant activity (1.1 mmol TEAC/kg) and (3.2 mmol Fe²⁺ /kg) in DPPH and FRAP assays. The chemical profiles were dominated by source plant-originated benzene derivatives: 3,4-dihydroxybenzoic acid (up to 8.7 mg/kg, HPLC/honey solution), methyl syringate (up to 14.5%, GC/solvent extracts) or benzaldehyde (up to 43.7%, GC/headspace). Other markers were terpenes including norisoprenoid (4-hydroxy-3,5,6-trimethyl-4-(3-oxobut-1-enyl)cyclohex-2-en-1-one, up to 20.3%, GC/solvent extracts) and monoterpenes, mainly linalool derivatives (up to 49%, GC/headspace) as well as borneol (up to 5.9%, GC/headspace). The application of various techniques allowed comprehensive characterisation of FHH. 4-Hydroxy-3,5,6-trimethyl-4-(3-oxobut-1-enyl)cyclohex-2-en-1-one, coniferyl alcohol, borneol, and benzaldehyde were first time proposed for FHH screening. Protocatechuic acid may be a potential marker of FFH regardless of the geographical origin.

Keywords: Antioxidants; Bioactive compounds; Lignin derivatives; Terpenoids; Volatiles.