Improvement of physicochemical and rheological properties of kombucha fermented milk products by addition of transglutaminase and whey protein concentrate

The objective of this work was to investigate the effect of addition of transglutaminase (TG-0.02%, w/w) and whey protein concentrate (WPC-0.03%, w/w), on quality of kombucha fermented milk product. Samples were prepared from pasteurized semi-skim milk (0.9%, w/w fat) and kombucha inoculum (10%, v/v). The pH values were measured during the fermentation of milk (lasted until reached 4.5). Syneresis, water holding capacity and the product texture (firmness and consistency,) were assessed after production. Rheological properties of kombucha fermented milk samples were measured during ten days of storage. The sample containing TG had the lowest syneresis (21 ml), the highest water holding capacity (62%) and the highest textural characteristics (firmness - 23.99g, consistency - 626.54gs) after production. The addition of WPC to milk improved the rheological properties, while the addition of TG improved it even to a significantly greater extent after the production and during 10 days of the storage. [Projekat Ministarstva nauke Republike Srbije, br. 46009