The Effect of Different Salt Concentrations on the Physicochemical and SensoryProperties of Probiotic White Cheese Prepared by Ultrafiltration Method

Reducing of salt content in cheese production is an important challenge for the dairy industry. Based on consumer demand for functional and healthy food, in this study, the feasibility of salt reduction in ultrafiltered white probiotic cheese was studied.For this purpose, white probiotic cheese was prepared with different levels of salt (2, 3 and 4%) with two probiotic strains (Lactobacillus acidophilus and Bifidobacteriumlactis) using response surface methodology and central composite design, and evaluated during 60 days storage time. Fitted models showed a high correlation coefficient to predictselected response variables including chemical and sensory characteristics, survival of probiotic bacteria and textural propertiesin UF-cheese. ANOVA results showed that change in salt concentration had a significant effect on physicochemical characteristics, texture parameters and overall acceptance (P<0.05), while the survival of probiotic bacteria was unaffected.According to the obtained results, by increasing the salt concentration in cheese the syneresis and dry matter, as well as the hardness of the samples increased, while the acidity and cohesiveness were decreased.Viability of probiotic bacteria was affected by storage time, so that the number of Lactobacillus acidophilus in low salt probiotic cheese and atthe end of storage period was more than Bifidobacteriumlactis.Lowering the salt content of probiotic cheese led to a lower sensory acceptability.Optimum conditionsto producelow salt probiotic cheese throughBifidobacteriumlactisand Lactobacillus acidophiluswereobtained 2.61% salt ( 18 days storage) and 2.49% salt (60 days storage), respectively.