A RAPID METHOD FOR THE DETERMINATION OF FAT IN FOODSTUFFS BY INFRARED SPECTROMETRY

A rapid method for the determination of the fat content of foodstuffs by transmittance infrared spectrometry is described. Fat is extracted with a chloroform-methanol (2:1) solvent containing an apolar methylsilicone oil as an internal standard. After partitioning of both components into the chloroform layer, the areas of a strong absorption band at 5·72 μm representing carbonyl ester stretching of the fat and that of a strong band in the internal standard at 7·88 μm due to CH3Si stretching are recorded. Fat content is estimated from the band area ratio (fat/internal standard) using suitable calibration plots. The calibration strategy used is discussed in some detail. The method was tested on a diverse range of foodstuffs including dairy products, processed meats, biscuit and cakes, chocolate, salad dressings, etc., and the results obtained were generally in good agreement with those given by standard reference methods. © 1989.