DETERMINATION OF THE SOLID FAT-CONTENT IN MILK-FAT BY GAS-CHROMATOGRAPHIC TRIGLYCERIDE ANALYSIS

Milk fat from 440 butter samples obtained from more than 20 Northern G erman milk collection areas was extracted and the solid fat content (S FC) determined at 7 temperatures between 0 and 30-degrees-C using nucl ear magnetic resonance spectrometry. Further, all milk fats were analy zed gas chromatographically for their triglyceride composition. Using a multiple regression analysis triglyceride formulae have been compute d which enable the SFC-values to be theoretically calculated at all 7 measuring temperatures. The standard deviations between experimental a nd theoretical SFC-values at temperatures between 0, 5 . . ., 30-degre es-C ranged between 0.88 and 0.38% (r = 0.99990 and 0.99682). Also bet ween the fatty acids C18:1 (oleic acid with isomers), C16 (palmitic ac id) resp. C16/C18:1 and the SFC-values measured at 0-degrees-C relatio nships have been established (r = -0.95, 0.93 and 0.93, respectively). Since the expenditure in time necessary for gas chromatographic trigl yceride analysis by using simultaneously 2 columns can be reduced to 4 - 5 min and, in addition, extrelut columns allow a very fast isolatio n of fat from milk for gas chromatographic analyses, rapid characteriz ation of milk fat regarding solid fat contents or also milk fat hardne ss is feasible by means of triglyceride analysis. Besides the SFC-valu es a number of other milk fat parameters, such as iodine number, melti ng point, refraction index etc. can be determined using the same trigl yceride analysis.