Detection of adulteration of commercial honey samples by the ~(13)C/~(12)C isotopic ratio

摘要

It is very difficult to detect adulteration by conventional laboratory methods. However, differences in stable carbon isotope ratio (~(13)C/~(12)C = per thousand), between honey and its protein fraction give a qualitative and quantitative indication of honey adulteration. Forty honey samples from Brazil and eight imported from Argentina, Canada and the USA, were analyzed to detect possible adulteration by gas chromatography/mass spectrometry. Honey was adulterated with sucrose solution and high fructose corn syrup (HFCS) to determine detection limits. The ~(13)C/~(12)C value for honey and its protein fraction should not differ more than 1per thousand for delta (δ). The range of values found for bee-produced honey was -21.96per thousand to -30.47per thousand for C3 plants and -11.82per thousand to -19.00per thousand for C4 plants (produced near cut sugar cane and not considered to be flower honey). For cane sugar it was - 11.33per thousand to -11.78per thousand, and -9.70per thousand to -9.78per thousand for HFCS. Adulteration was found in six Brazilian honey samples.