Quality, Composition, and Adulteration Assessment of Flower Honeys from Afyonkarahisar Province, Türkiye

This study aimed to assess the physicochemical characteristics, antioxidant potential, sugar composition, and authenticity of ten flower honey samples collected from different regions of Afyonkarahisar Province, Türkiye. Comprehensive analyses were conducted to evaluate parameters such as moisture content, pH, free acidity, electrical conductivity, diastase activity, proline content, hydroxymethylfurfural (HMF), sugar composition, and antioxidant constituents (total phenolic and flavonoid content). Authenticity was assessed by analyzing the stable carbon isotope ratio (δ¹³C) by Combustion Module-Cavity Ring-Down Spectroscopy (CM-CRDS) to detect C4 sugar adulteration. All honey samples were determined to be authentic, with C4 sugar concentrations varying from 0.0% to 2.4%, remaining below the 7% limit established by international standards. Proline concentrations (369.8–557.5 mg/kg) and diastase activity (8.25–24.68 Schade units) demonstrated good maturation and enzyme stability. The moisture content (15.68–18.29%) and HMF values (0.0–24.75 mg/kg) adhered to Codex Alimentarius and EU regulations, hence affirming freshness and appropriate processing. The total phenolic content varied between 58.00 and 107.72 mg GAE/100g, whereas the total flavonoid content ranged from 6.34 to 15.89 mg QE/100g, indicating the diversity of floral sources and potential antioxidant activity. The sugar analysis indicated elevated concentrations of glucose and fructose (65.1–72.0 g/100g combined), with no detectable sucrose or maltose present in any sample. The results confirm that the analyzed flower honeys are of high-quality, unadulterated, and comply with international standards regarding composition and authenticity. These findings highlight the need of combined physicochemical and isotopic studies for ensuring honey quality and safeguarding consumers.