2.6. pH and microbiology of yogurt
Yogurt pH was measured using a pH meter (Seven Easy portable,
Mettler-Toledo GmbH, Switzerland) by directly inserting the pH probe
into the yogurt samples. Streptococcus thermophilus and Lactobacillus
delbrueckii subsp. bulgaricus counts were determined in yogurt using
the pour plate techniquewithM17 agar (supplementedwith sterile lactose
solution (10% w/v)) (Oxoid Ltd.) and MRSA (de Man, Rogosa and
Sharpe agar), respectively. The MRSA plates were placed in heatsealed
bags in the presence of Anaerocult® A (Merck Millipore,
Germany). The MRSA and M17 plates were incubated at 37 °C for
4 days. Results were expressed as log10CFU (colony forming units)/g
yogurt.