¹³C-Pattern of Natural Glycerol:  Origin and Practical Importance

Abstract

The average δ 13 C-value of glycerol from plant origin is 4-5‰ more negative than that of carbohydrates from the same source. This depletion is exclusively dealing with position C-1 of the molecule. This is also observed for glycerol from other natural sources, although to a smaller extent, while synthetic glycerol shows a statistical 13 C-pattern. On the basis of these data an illegal addition of glycerol to wine should be detectable. In fermentations of glucose with yeast the extent of the depletion in position C-1 of glycerol proved to be reciprocal to its yield. Furthermore a total carbon and isotope balance showed that the depletion of glycerol is a compensation for small 13 C-enrichments in the corresponding positions of main products. An isotope effect on the aldolase reaction and a noncomplete equilibration of the triose phosphates are discussed as main reasons for these findings.

Olive Oil Traceability

“…It is nominally present in its ester form as glycerolipids in fats and oils (Kiritsakis and Christie, 1999). Glycerol is bio-synthesised relatively early in the lipidic metabolic pathway compared to fatty acids (Weber et al, 1997;Harwood and Sánchez, 1999).…”

Methods of Detecting Adulteration of Wines

“…Ponadto wpływa na zawartość ekstraktu bezcukrowego, który jest podstawą klasyfikacji jakościowej win w wielu krajach Europy. Glicerol jest dodawany do win w celu zamaskowania ich niskiej jakości [6,31].…”

Gas chromatography coupled to mass spectrometry for analyses of organic compounds and biomarkers as tracers for geological, environmental, and forensic research

“…Weber et al [30] suggested the depletion of 13 C in the C1 position in natural glycerol as a unique feature to test for illegal addition of synthetic glycerol to wines. GC -IRMS was also used to determine the authenticity of wine, fruit juices, and honey, and to prove fraudulent addition of sugars and even vitamin C from other sources [318].…”