delta(13)C- and delta(18)O-values of glycerol of food fats.
The average values of carbon and oxygen isotopic contents (delta(13)C and delta(18)O) of 36 glycerol samples from fats have been determined. The examined samples arise from many fats of animal and plant origin, as well as from the three Italian hard cheeses Parmigiano-Reggiano, Grana Padano and Trentingrana. The total (13)C content allows one to distinguish between glycerol from plants with the C-4 carbon fixation pathway (maize, mean delta(13)C = -14.4 per thousand) and that from plants with the C-3 pathway (mean delta(13)C = -30.7 per thousand). The delta(13)C-values of glycerols of animal origin seem to depend on the diet of the animal, as suggested by the mean values -29.6, -29.0 and -25.1 per thousand, respectively, observed for Parmigiano-Reggiano, Trentingrana and Grana Padano. Additionally, the mean total (18)O content of glycerol samples of vegetable origin is approximately 23.8 per thousand, while that from animal fat is 15.1 per thousand. However, the delta(18)O mean values relative to Parmigiano-Reggiano, Grana Padano and Trentingrana are 11.8, 16.0 and 13.8 per thousand, respectively. The combination of the (13)C and (18)O measurements relative to the fat glycerol of the three cheeses might be considered a potential criterion of authentication.
Fronza
G
G
Dipartimento di Chimica del Politecnico, Centro CNR per la Chimica delle Sostanze Organiche Naturali, Via Mancinelli 7, 20133 Milano, Italy.
Fuganti
C
C
Grasselli
P
P
Serra
S
S
Reniero
F
F
Guillou
C
C
D000818:Animals; D002079:Butter / Q000032:analysis; D002247:Carbon Isotopes / Q000032:analysis*; D002417:Cattle; D004041:Dietary Fats / Q000032:analysis*; D005395:Fish Oils / Q000032:analysis; D005990:Glycerol / Q000737:chemistry*; D006115:Greece; D007558:Italy; D013058:Mass Spectrometry; D010103:Oxygen Isotopes / Q000032:analysis*; D010938:Plant Oils / Q000737:chemistry; D014416:Tunisia
D002247:Carbon Isotopes; D004041:Dietary Fats; D005395:Fish Oils; D010103:Oxygen Isotopes; D010938:Plant Oils; D002079:Butter; D005990:Glycerol