PHYSICO-CHEMICAL PROPERTIES OF PROBIOTIC YOGHURT PRODUCED WITH TRANSGLUTAMINASE

The effect of different concentration of transglutaminase- TG (0.02%, 0.06 % and 0.12%) on physico-chemical properties of probiotic yoghurt was investigated. Two series of yoghurt were manufactured on a laboratory scale from pasteurised skim milk (0.1 % w/w fat). Series I was produced with TGase activation during a period of 2 h at 40°C, while series II was produced without enzyme activation. Then, the adequate quantities of TGase and probiotic starter culture ABT-4 (Chr. Hansen A/S Denmark) were added. Chemical composition, physico-chemical properties (water holding capacity and whey separation) and sensory characteristics of yoghurt samples were determined after pro-duction and during 5 days of storage. Addition of TGase to milk (direct or after activa-tion) for probiotic yoghurt manufacture improved its overall characteristics. Activation of TG in yoghurt production increases water holding capacity as well as decreases syneresis during the storage