Effect of Selected Yogurt Cultures on the Concentration of Orotic Acid, Uric Acid and A Hydroxymethylglutaric‐Like Compound in Milk After Fermentation

摘要

ABSTRACTEight yogurts, each fermented by different strains ofLactobacillus bulgaricusandStreptococcus thermophilus, were produced, then analyzed using high‐performance liquid chromatography (HPLC) for the presence of orotic, uric and 3‐hydroxy‐3‐methylglutaric (HMG) acids. In all yogurts orotic acid decreased 15‐53 after fermentation while uric acid levels did not change. A compound was found in all yogurt extracts that co‐chromatographed with HMG on HPLC and had a similar UV spectrum to HMG after both were collected from a reverse phase HPLC column. However, the HMG co‐elutant did not correspond to HMG on thin‐layer or paper chromatography. These results suggest that HMG is not present in milk or yogurt. Fermentation of milk by yogurt strains reduced the concentration of the HMG co‐elutant in six of the yogurts, but increased