Isolation, Quantification, and Biosynthetic Origin of Orotic Acid in Milk

The most frequently used methods for estimating orotic acid in milk have been variations of a colorimetric procedure. Assay here involves the isolation of orotic acid by dialysis and anion exchange and silicic acid chromatography. This is fob lowed by the silylation of the purified orotic acid and its quantification by gas-liquid chromatography. This technique was compared with a colorimetric method on various milk samples and the results by the two methods were similar. Both confirmed the high orotic acid content of bovine milk. Orotic acid was less in commercial cultured buttermilk and goat milk and not detectable in human milk.