The HPLC method described by Fernandez‐Garcia and McGregor (1994) was carried out for the analysis of organic acids with some following modifications. Yogurt samples (5 g) were weighed into 30 ml Teflon centrifuge tubes and diluted to 25 ml by 0.01 N H2SO4. The tubes were mixed for 1 min on a vortex mixer. Resulting mixtures were centrifuged at 7000 g for 7 min at 5°C in a refrigerated centrifuge (Sigma 3K30, Germany). Supernatant fractions were filtered through 0.45‐μm nylon filter (Supelco Iso‐Disc™, N‐25‐4 Nylon, 25 mm) into an HPLC vial.