Determination of orotic acid in whey and modified whey products.

The concentration of orotic acid in dry whey ranged between 64 and 146 mg/100 g and appeared dependent on whey type. The orotic acid of modified whey products, prepared commercially by electrodialysis, ultrafiltration, gel filtration, or polyphosphate precipitation was between 7 and 124 mg/100 g, which was less than that of dry whey. It appears that whey processing methods do not concentrate orotic acid in whey fractions.