Effects of Fermentation and Storage on the Concentration of Orotic Acid and Uric Acid in Skim Milk

Abstract

Skim milk (SM) and skim milk yogurt (SMY) were produced and analyzed using high performance liquid chromatography (HPLC) for the presence of two organic acids-erotic acid (OA) and uric acid (VA). The concentration of OA in SM and SMY at 0 days was 106.2 and 46.1 ppm, respectively. After fermentation OA concentration was 56% lower (P <0.05) in SMY than in nonfermented SM. UA content of SM and SMY at 0 days was 23.3 and 20.1 ppm, respectively. Unlike OA, the UA contents were not significantly altered after fermentation. No significant differences were detected in the concentrations of OA and UA when values of Sm and SMY of 0 days were compared with those after 3 days storage.

Effect of lactic starter cultures on the organic acid composition of milk and cheese during ripening—analysis by HPLC

“…The decrease of orotic acid, during the incubation period, could be due to the consumption of this acid as growth factor by LAB (Suzuki et al 1986). Similar observations were reported by other authors during yogurt fermentation (Saidi and Warthesen 1989;Navder et al 1990). On the other hand, citrate-fermenting strains present in the starter cultures are responsible for the great decrease of citric acid observed.…”