Determination of the Major Free Fatty Acids of Cheddar Cheese

Abstract

The major individual free fatty-acids (FFA) (acetic through linolenic) were determined in 14 samples of Cheddar cheese by column chromatography plus gas-liquid chromatography. Formic-and propionic-acids did not occur in any of the cheeses. Acetic-acid showed the greatest variability in concentration and was usually the most abundant. Among the FFA which can arise through the hydrolysis of milk fat, free butyric-acid always occurred in about twice the percentage reported for estertfied butyric-acid. The individual FFA from caproic through linolenic, were present in nearly the same ratio as the same ester-ified acids in milk fat. Excluding 2 rancid samples, the average concentrations (expressed as mg of FFA/kg of cheese) were as follows: 2:0, 865; 4:0, 115: 6:0, 38; 8:0, 41: 10:0, ,49; 12:0, 81; 14:0, 218; 16:0, 503; 18:0, 172; 18:1, 467; 18:2, 69; 18:3, 40. In the rancid samples, the concentrations of acetic-acid fell within the range found in the 12 other samples. Each of the individual FFA from butyric through linolenic, however, was present in the rancid samples in about 10 times the average concentration found in the 12 other samples.