Effect of transglutaminase and whey protein concentrate on textural characteristics of low fat probiotic yoghurt

Abstract

The objective of this work was to study the effect of addition of transglutaminase (TG - 0.01 % and 0.02% [w/w]), whey protein concentrate (WPC - 0.3%, 0.4% and 0.5% [w/w]), and a combination of 0.01 % [w/w] TG and 0.3% [w/w] WPC, on the quality of stirred yoghurt. Yoghurt samples were prepared from two batches of pasteurized skim milk (0.1 %w/w fat) and probiotic starter culture. Syneresis and water-holding capacity were determined as relevant physico-chemical characteristics, while the product texture was assessed through firmness, consistency, cohesiveness and index of viscosity. Addition of TG to milk improved the product quality, while the addition of WPC improved it even to a significantly greater extent. However, a combination of TG and WPC decreased the yoghurt's textural properties.