Influence of prebiotic fibers on yogurt properties

The study evaluated the influence of prebiotic fibers Fibregum, Equacia, Floracia and Raftilose on colour characteristics, physical, chemical, syneretic, and rheological properties of yogurt and the changes in these properties while the product is stored at 6 degrees C for 14 days. Fibers (3%) were added to the yogurt and were dissolved by stirring. The fibers significantly changed the yogurt colour characteristics - evaluated samples with fiber were darker than the control samples. Raftilose did not have any influence on coordinate b(star); other supplements resulted in a yellowish colour. Equacia and Raftilose had the most significant influence on coordinate a(star). During the storage period, the colour characteristics of the yogurt did not change. All fibers improved the syneretic stability of the yogurt - Equacia had the most significant effect. According to flow curves within the evaluated shear rate range (0-500 s(-1)), the strongest structure was observed in the yogurt sample with Equacia. Other fibers had a lower influence on the measured rheological properties of yogurt compared to the control sample. None of the fibers influenced the acidity of the fresh or stored yogurt.