Impact of prebiotics on the rheological characteristics and volatile compounds of Greek yogurt

The objective of this study was to evaluate the effect of the addition of prebiotics (xylooligosaccharide, galactooligosaccharide, polydextrose, fructooligosaccharide, or inulin) on the quality parameters of Greek yogurt. Composition, rheological parameters, and the volatile compounds profile were evaluated. The effect of prebiotic addition was dependent on the type of the component used. The addition of galactooligosaccharide, polydextrose, and inulin resulted in more consistent (increase in k and decrease in n), elastic (increase in G'), viscous (decrease in tan delta) and firm products (increase in G* and z). In addition, the volatile compounds profile was diverse, with the appearance of isobutyric acid, 5-hydroxy-2,7-dimethyl-4-octanone, 2 (5H) -furanone and/or 2-hydroxy-3-pentanone, which contributes to the sweet aroma, sweet taste, and buttery flavor of the products. The addition of fructooligosaccharides had a negative impact on the rheological parameters, resulting in less consistent, elastic, viscous, and firm products. The addition of xylooligosaccharide resulted in products with intermediate characteristics. Therefore, galactooligosaccharide, polydextrose, and inulin proved to be technological and interesting alternatives for the manufacture of prebiotic Greek yogurts.