Sensory evaluation of low-fat yoghurt produced with microbial transglutaminase and comparison with physicochemical evaluation.

ABSTRACT

BACKGROUND: Low-fat or non-fat yoghurts are popular nowadays. However, their texture is not good and they show considerable syneresis with time. The aim of this research was to evaluate the effect of the application of transglutaminase (TG) to low-fat yoghurt to determine if similar sensory properties to those of full-fat yoghurt can be obtained. Methods of adding TG (prior or simultaneous with fermentation), dose, and TG origin were evaluated. Correlations between sensory and physicochemical parameters were assessed. RESULTS: The results showed no significant differences between TG addition methods in terms of the quantitative and qualitative sensory attributes studied. Simultaneous addition of TG was preferred to speed up the process. A dose of 1 U g-1 was selected as optimal. Few differences were detected due to the origin of the TG. They were not significant although some differences were observed in terms of density, bitterness, and syneresis compared with low and full-fat yoghurts. CONCLUSION: The results showed that sensory parameters cannot be associated with only one physicochemical parameter in yoghurt evaluation. Transglutaminase can be used as a substitute for stabilizers in the production of low-fat yoghurt, maintaining good sensory properties and avoiding initial syneresis. © 2018 Society of Chemical Industry.