Lactobacillus acidophilus counts were enumerated as described by Dave and Shah (1996) with some modifications. Sterilized and tempered (45°C) MRS agar (90 mL) was supplemented with filter-sterilized D-sorbitol solution (10 mL), prepared by dissolving 10 g D-sorbitol (Fisher Scientific) in 100 mL of distilled-deionized water, just before plating. Yogurt samples were serially diluted using sterilized 0.1% peptone water, pour plated using supplemented MRS agar, and incubated anaerobically using anaerobe gas packs at 37°C for 72 h. Lactobacillus acidophilus colonies were confirmed using Gram staining and the API 20 A system (bioM erieux, Inc.).