Effects of exopolysaccharide-producing starter cultures on physicochemical, rheological and sensory properties of fermented camel’s milk

The aim of this study was to examine the influence of using exopolysaccharide (EPS) producing starter cultures on physicochemical, rheological and sensory properties of fermented camel milk. Four starter cultures of the strains of non-EPS and EPS-producing were combined and distribution in four treatments portions to made yoghurt from camel’s milk. Results showed that the maximum acetaldehyde and diacetyl contents were found in control treatment during 7 days storage period. The EPS concentration was detected between 41.3 to 269.3 mg/kg in the yoghurt made with non-EPS and EPS-producing starter cultures. The highest EPS concentration was observed in treatment C (1.5% EPS-producing Streptococcus thermophilus plus 1.5% non EPS-producing Lb. delbrueckii ssp. bulgaricus) during 14 days storage period, then reduced at the end of the storage period. Yoghurt made with any EPS-producing strains had significantly (P 0.05) lower firmness, syneresis and higher viscosity values than control yoghurt. Overall acceptability scores of the sensory evaluation revealed that the yoghurt made with EPS-producing starter cultures in treatment C was the most accepted, while the control treatment was the least. According to the results, exopolysaccharide enhance viscosity, texture and mouthfeel and to avoid syneresis in yoghurt. The results of this study suggest that the use of EPS-producing cultures could provide better textures for camel milk yoghurt than those imparted by additives.