A method to investigate on glycerides in cow's milk and dairy product fats

The official Italian legislation describes the milk fat analysis of triglycerides by assuming the result mathematically elaborated as characterizing parameter. This paper proposes an alternative HPLC method of qualitative and quantitative analysis, easier, faster and more suitable than the official Italian method. For this purpose, samples of raw and pasteurised milk and cheeses obtained from the same milk were analysed. According our method, the fat is dissolved at room temperature in the eluente used for HPLC. A gradient elution with evaporative light-scattering detector (ELSD) yields good results in short time. The proposed method performs qualitative and quantitative analysis. Diand tri- glycerine esters, cholesterol and cholesteryl derivates were determined. Limit of detection (LOD = 4 ppm) and limit of quantification (LOQ = 8 ppm) were also obtained. Chromatograms obtained for cheese qualitatively coincide with those of milk of provenience.