Improved detection of honey adulteration by measuring differences between¹³C/¹²C stable carbon isotope ratios of protein and sugar compounds with a combination of elemental analyzer - isotope ratio mass spectrometry and liquid chromatography - isotope ratio mass spectrometry (δ¹³C-EA/LC-IRMS)

Abstract

-The detection of honey adulteration with invert sugar syrups from various C3 and C4 plant sources was realized by coupling an isotope ratio mass spectrometer both to an elemental analyzer and to a liquid chromatograph (EA/LC-IRMS). For 451 authentic honeys measured, the individual δ 13 C values of bulk honey, its protein fraction, fructose, glucose, and di-and trisaccharides ranged from -22.5 to -28.2% and did not show differences (Δδ 13 C) of more than ± 0.9% (average), with a maximum standard deviation of 0.7% . The Δδ 13 C (fructose -glucose) value was significantly lower (0 ± 0.3% ). Based on the obtained results and considering a confidence level of 99.7%, the following limits for Δδ 13 C values of authentic honey are proposed: Δδ 13 C max.: ± 2.1% (maximum difference between all measured δ 13 C values); Δδ 13 C fruglu: ± 1.0% ; Δδ 13 C (% ) protein -honey: -1.0% . The newly developed EA/LC-IRMS method and the purity criteria defined represent a significant improvement compared to existing methods.honey / adulteration / LC-IRMS / EA-IRMS / δ 13 C values / C3 sugar / C4 sugar

Saf ve Değişik Şekerlerle Beslenmiş Kolonilerden Üretilmiş Ballara Ait Sabit ve Ayrimsama Fonksiyonu Katsayilari İle Bal Örneklerinin Kaynağının Tahmini

“…For this reason, this characteristic, which is considered a formal method, creates the basis for many standards [2,15,28] . The finding that the C 4 ratio ranked first in the Stepwise method confirms the importance of this characteristic as mentioned in previous studies [1,4,16] . Similarly, the difference between the δ 13 C value of honey and its protein, which is used to determine the C 4 plant-derived adulteration, was found to be significant in the Stepwise method.…”

“…For pure blossom honey (control), and adulterated honey samples: δ 13 C values were determined by isotope ratio mass spectrometry (EA-IRMS) after complete sample combustion to carbon dioxide, as described by AOAC [23] method 991.41. The C 4 % sugar contents in honey samples were determined using the AOAC (998.12) standard [1,4,7] . Statistical analysis: The Multivariate Discriminant Stepwise Analysis Method (MDASM), which determines differences and grouping levels in terms of biochemical characteristics between more than two biological sources, was used to determine the SMCDFCDC of pure and adulterated honey samples produced from 20 and 100 L/colony syrup levels of HFCS.85, HFCS.55 and SS [22] .…”

“…Honey can be adulterated by adding different industrial sugar syrups (glucose and fructose) obtained from starch by heat, enzyme or acid treatment to the honey [4] or by feeding the bee colonies with excessive amounts of these syrups during the main nectar flow period [5,6] . These practices not only deteriorate honey quality but also lead to losses for Origin Estimation of Honey Samples ... unadulterated honey producers and cheat consumers [7,8] .…”

“…Many characteristics have been evaluated for different purposes. These characteristics are as follows: amino acid content [9] , carbon isotope ratio (δ 13 C/ 12 C) and C 4 % rate [1,4,6,10] , protein profile, aroma, melissopanalogic analysis [11][12][13] , organoleptic characteristics [14] and biochemical characteristics [2,5,15] . There has been discussion as to which characters or methods are reliable in distinguishing adulterated honey produced by adding sugar syrup (direct adulteration) or by excessively feeding bee colonies with industrial sugar syrup (indirect adulteration).…”

“…There has been discussion as to which characters or methods are reliable in distinguishing adulterated honey produced by adding sugar syrup (direct adulteration) or by excessively feeding bee colonies with industrial sugar syrup (indirect adulteration). Although carbon isotope ratio (δ 13 C/ 12 C) and C 4 % rate have been accepted as the most reliable characteristics, they are not sufficient for discriminating honeys adulterated using sugars originating from C 3 plants such as sugar cane and wheat [4,6,16] .…”