Physicochemical and Sensorial Properties of Probiotic Yogurt as Affected by Additions of Different Types of Hydrocolloid

The main attributes of yogurt that affect consumer satisfaction are taste, consistency, and a firm texture. This study evaluate sthe influence of xanthan gum, barley beta-glucan, and guar gum in concentrations of 0.05%, 0.1%, 0.2%, and 0.3% on pro-biotic yogurt. The set-type yogurt samples were prepared by using raw cow's milk. The statistical analysis showed that noneof these gum additions had any marked effect on pH, titratable acidity, total solids content, and probiotic bacteria counts ofyogurt samples. Evaluations for syneresis and water-holding capacity (WHC) in the yogurt samples were affected by the typeand concentration of the stabilizer. Yogurts treated with 0.1% xanthan gum and 0.3% beta-glucan recorded the highest WHCand the least syneresis. The largest amount of gel firmness was recorded in yogurt samples treated with 0.2% xanthan gumand 0.3% beta-glucan. Yogurt samples treated with 0.1% xanthan gum and 0.3% beta-glucan were considered acceptable bytrained panelists and gained the highest scores in sensory evaluations. The correlation coefficient between the amount of sy-neresis, WHC and stiffness of texture was significant compared to scores for sensory evaluation ( p<0.01). Results for effectsof guar gum on the tested parameters were contrary to the results expected from a gum. According to this study, the use ofxanthan gum and beta-glucan are highly recommended for low-fat yogurt production.Key words: hydrocolloid, probiotic yogurt, sensorial properties, syneresis