Evaluation of textural and organoleptic properties of yogurts produced using lactic acid bacteria isolated from ewe’s yogurts from Mashhad, Hamedan and Dezful

Eve’ yogurt is one of the nutritive dairy products in Iran. The aim of this study was molecular identification of lactic acid bacteria isolated of ewe yogurts from 3 different regions of Iran (Mashhad, Dezful, and Hamedan) and assessment of their technological properties. A total of 47 isolates were molecularly identified by PCR of 16S rDNA gene and sequencing. Isolates were evaluated for technological properties including Lactic acid and diacetyl production, lipolytic, urease, and proteolytic activities. The statistical analysis of data using SPSS software indicated that diacetyl production and pH changes by bacterial isolates for 24 hours were significantly (P<0.05) different among yogurts from Dezful, Hamedan and Mashhad. The technological properties of isolates demonstrated that Streptococcus salivarius subsp. thermophilus (H1, H2) and Lactobacillus delbrueckii subsp. bulgaricus (H1, H2, H3, H7, H9, H10) of ewe’s yogurt from Hamedan have high technological properties. Also, based on the analysis results of the organoleptic properties and texture stiffness of yogurts produced by selected isolates, S. salivarius (H2) and L. delbrueckii (H3) suggested as a suitable starter culture.