Detection of sugar syrup adulteration in honey using ethanol isotope ratio mass spectrometry (EIM-IRMS)

Food adulteration, particularly in honey, poses a global concern due to its impact on product quality and safety. In this study, honey samples were produced under controlled feeding conditions, using syrups from C3 and C4 plants at varying levels. Free acidity, moisture content, pH, electrical conductivity, sugar composition, diastase activity, HMF, and proline content were analyzed to evaluate honey quality. While these parameters provided valuable insights into general quality and authenticity, they proved to be insufficient for the exact detection of adulteration. Although Isotope Ratio Mass Spectrometry (IRMS) is an established tool for this purpose, Elemental Analyzer-Isotope Ratio Mass Spectrometry (EA-IRMS) successfully identified C4-type adulteration, but failed to detect C3-type adulterants through δ13C analysis alone. The EIM-IRMS (Ethanol Isotope Measurement–Isotope Ratio Mass Spectrometry) method, which measures the non-exchangeable hydrogen isotope ratios (δDn) in ethanol derived from honey, demonstrates superior sensitivity in detecting C3-type adulteration. Ethanol δDn values for adulterated samples differed significantly from controls, enabling clear discrimination.