The Optimization of Sheep,s Yogurt Drink(Doogh) Containing Transglutaminase Enzyme and Ziziphora Essence

Yoghurt drink (doogh) is a nutritions fermented dairy product. The aim of this study was to determine the effect of transglutaminase (0, 0.025, 0.050, 0.075 and 0.1%) and ziziphora essence (0.001 and 0.01%) on physicochemical (pH, acidity (Dornic), dry matter%, fat%, viscosity (CP), serum seperation%) and sensory properties including (taste, flavor, aroma, color, appearance, texture and overall acceptability) of yoghurt drink (doogh). The results showed that as the amounts of transglutaminase and ziziphora increased, pH from 4.05 to 4.50, dry matter% from 5.40 to 5.85 and viscosity (CP) from 12.32 to 12.70 CP increased and acidity (Dornic) from 46 to 42.67 and serum seperation% from 0.87 to 0.5 decreased. Fat content of all treatments were 1.20%. the results for sensory evaluation showed T4 containing (0.075 % of transglutaminase enzyme + 0.001 % ziziphora essence) and T5 containing (0.1% of transglutaminase enzyme + 0.001 % ziziphora essence) had the highest sensory evaluation scores. Due to the lowest amount of serum seperation, high viscosity and the highest scores of sensory evaluations, T5 containing 0.1% transglutaminase enzyme and 0.001% ziziphora essence was selected as the best among others.