The Effect of Inulin and Lactulose on survival of Lactobacillus casei and physicochemical and sensory characteristics of probiotic Ultrafiltrated Feta Cheese

Introduction: The consumption of synbiotic products (simultaneous presence of probiotic and prebiotic) has beneficial effects on human. The aim of this study was to evaluate the effect of inulin and lactutose on the characteristics of probiotic ultrfiltrated feta cheese. Materials and Methods: In this study, prebiotic compounds consisting of inulin and lactulose (solely or in combination together) and Lactobacillus casei were used to produce probiotic ultrafiltrated Feta cheese. The survival of Lactobacillus casei and physicochemical and sensory properties of probiotic ultrafiltrated (UF) cheese concerned with different storage days (1, 15, 30, 45 and 60 days) were evaluated. Results: pH values for all the cheese samples were decreased significantly (P<0.05) during storage. In other word, the amounts of acidity for all of the samples increased significantly during storage (P<0.05). Moisture variation and contents were in a decreasing trend until the end of the storage period (P<0.05). Sample containing inulin (I), sample containing lactulose (L) and sample containing inulin and lactutose (IL) had the best sensory quality in comparison to the control sample (C). At the end of the storage, the number of Lactobacillus casei was higher in samples I, L and IL as compared to the control. Conclusion: In this research work, the final synbiotic cheese containing more than 107 CFU/g viable Lactobacillus casei at the end of storage might be regarded as a probiotic product. The prebiotic compound has improved sensory and physicochemical properties as well as viability of Lactobacillus casei in probiotic ultrafiltrated Feta cheese as compared to the control.