In common with most jurisdictions, India has regulatory analytical criteria for authentic honey. This includes various stable isotope ratios.
In this study (open access) the researchers set out to construct an analytical database of fully traceable authentic honeys in order to verify the criteria set by the Food Safety and Standards Authority of India.
They collected 98 authentic samples (covering 19 botanical sources, 42% multifloral and 58% monofloral). They covered 17 states and provinces. Sample were from collection centres of the All-India Coordinated Research Project on Honey Bees and Pollinators (AICRP, HB&P), under the auspices of the Indian Council of Agricultural Research (ICAR). In addition, beekeepers registered with the National Bee Board (NBB) were also identified for sample collection. All samples were fully traceable.
The researchers generated a database of stable carbon isotope ratios (13C/12C) by Elemental Analyzer/Liquid Chromatography–Isotopic Ratio Mass Spectrometry (EA/LC-IRMS). The samples were analyzed for the parameters δ13CHoney(δ13CH), δ13CProtein(δ13CP), δ13C individual sugars, ∆δ13CProtein-Honey(δ13CP-H), C4 sugar, ∆δ13CFructose-Glucose(δ13CFru-Glu), ∆δ13Cmax, and foreign oligosaccharides as per the official methods of analysis of the Association of Official Analytical Chemists (AOAC 998.12) and the FSSAI.
The results were evaluated against the published literature and Indian regulatory criteria for authentic honey. The δ13C value for honey (δ13CH) ranged from −22.07 to −29.02‰. It was found that 94% of samples met the criteria for Δδ13CP-H (≥−1.0‰), Δδ13CFru-Glu (±1.0‰), and C4 sugar content (7% maximum), with negative C4 sugar values treated as 0% as prescribed by the AOAC method. 86% of samples met the accepted foreign oligosaccharide criteria (maximum 0.7% peak area).
They conclude that the data of this study provide scientific backing for these four parameters as per the FSSAI regulation. However, the non-compliance of a high number (47%) of authentic honey samples for Δδ13Cmax (±2.1‰) compels further systematic investigation with a special focus on bee feeding practices. Further, they found that honey samples with a Δδ13CP-H greater than +1‰ and a C4 sugar content more negative than −7% also did not comply with the Δδ13Cmax criteria. They suggest that Δδ13CP-H values (>+1‰ equivalent to C4 sugar < −7%) could be an indicator of C3 adulteration to some extent.