Survival of Bifidobacterium bifidum in cow- and camel-milk yogurts enriched with Cinnamomum verum and Allium sativum

Abstract

The effects of Allium sativum and Cinnamomum verum water extracts on the survival of Bifidobacterium bifidum during 21 days of refrigerated storage and after simulated gastrointestinal digestion (SGD) were investigated. Two types of yogurt (cow- and camel-milk yogurts) were prepared in the presence of A. sativum or C. verum. The viable cell counts (VCC) of B. bifidum in fresh A. sativum- or C. verum-cow milk yogurt (1 day) were higher (8.1 · 109 cfu/ml and 6.6 · 109 cfu/ml, respectively; p < 0.05) than plain-yogurt (1.9 · 109 cfu/ml). In contrast, B. bifidum VCC in fresh plain-camel milk yogurt was 1.99 · 109 cfu/ml whereas the presence of A. sativum or C. verum in yogurt increased (p < 0.05) VCC to 19.61 · 109 cfu/ml and 25.55 · 109 cfu/ml, respectively. The VCC of B. bifidum in both herbal-yogurts decreased (p < 0.05) during refrigerated storage for both types of yogurt. The VCC of B. bifidum was 1.3 · 109 cfu/ml in all fresh cow milk yogurts after 1 h gastric digestion. Intestinal digestion (1 h) increased VCC of B. bifidum in all fresh yogurts but not in 7 day old yogurts (plain- and A. sativum-yogurts). However, prolonged digestion to another 1 h in intestine reduced (p < 0.05) VCC of B. bifidum in all fresh and storage yogurts. In contrast, all fresh camel milk yogurts showed VCC of B. bifidum 61 · 109 cfu/ml after SGD. Seven day old A. sativum – camel milk yogurt showed the lowest survival of B. bifidum after gastric digestion compared to plain- and C. verum-yogurt. The VCC reduced (p < 0.05) in all camel milk-yogurts after 2 h intestinal digestion.