Direct Gas-Chromatographic Measurement of Acetic, Propionic, and Butyric Acids in Milk Serum and Aqueous Extracts of Cheese

Aeetic, propionic, and butyric acids in milk and ripened cheeses were separated quantitatively by a gas-chromatographic technique, using uncoated porous polyaromarie polymer beads as the column packing. Milk sera and aqueous extracts of ripened cheeses were injected directly on to the column and the eluted fatty acids estimated by a hydrogen flame detector. Quantitative recoveries of acetic, propionic, and butyric acids added to milk were obtained. The sensitivity of the method is sufficient for cheese-ripening studies.