Spectrophotometric Determination of Protein and Fat in Milk Simultaneously

Abstract

A completely clear solution was obtained by adding 5 ml of 97% acetic acid to 0.05 ml of whole milk. The protein was calculated from the absorbance at 280 m~. Turbidity depending on fat content was developed thereafter by adding 2.5 ml of a solution containing 20% urea and 0.2% imidazole. The fat was determined from absorbance at 400 m~ with a round cuvette. This method does not require prehomogenization of milk for turbidity measurement, because of a dispersing effect by the combination of reagents. Application of this method to other food products is suggested.