Production and characterization of synbiotic Doogh, a yogurt-based Iranian drink by gum arabic, ginger extract and B. bifidum

The objective of this study was to determine the effects of using ginger extract and gum arabic as a prebiotic on the viability of Bifidobacterium bifidum and physico chemical properties of Doogh (yogurt drink) during storage at 4 degrees C for 30 days. The results showed that by increasing the amounts of gum arabic to 0.5%, B. bifidum count increased significantly (P < 0.05), but further increasing of the gum arabic, had no significant effect on B. bifidum count (P > 0.05). By increasing the amounts of gum arabic, the viscosity of the Doogh samples was increased and phase separation was reduced significantly (P < 0.05). The Doogh sample containing 0.25% gum arabic and 0.25% ginger extract had the highest number of probiotic population. Results showed that addition of B. bifidum increased acid development (degrees D) in Doogh samples during storage. In addition, phase separation in Doogh enriched by gum arabic was slower compared to control sample and the samples containing ginger extract. Doogh samples containing 0.25-1% gum arabic alone showed acceptable stability during storage time at 4 degrees C. In general, Doogh sample containing 0.25% ginger extract and 0.5% gum arabic gained the highest overall acceptability score in comparison with the other samples.