Spray-dried potato juice, a raw material with pro-health properties that have already been described in recent literature, was used to substitute a part of wheat flour in bread. Bread was chosen based on its popularity. This paper is a report on the results of this substitution. Three levels of flour replacement were chosen - 2.5, 5.0 and 7.5% (with respect to the mass of flour). The influence of potato juice addition on some of the most important characteristics of wheat bread was determined. Mixes of wheat flour and spray-dried potato juice were analyzed for fermentative and pasting properties. Baked bread samples were analyzed for their texture, color, consumer acceptance and antioxidant activity. The substitution influenced the volume of the loaf as gasses were not retained by the underdeveloped gluten network. Spray-dried potato juice was also found to influence the pasting properties. The viscosity values (peak viscosity, trough and final viscosity) determined with the RVA device were increased in pastes obtained from raw material mixtures with spray-dried potato juice. These crumb also showed increased firmness and chewiness as well as decreased springiness in the performed texture profile analyses. Spray-dried potato juice was also found to impact the color of bread crumb to an extent noticeable to the human eye. The bread that contained spray-dried potato juice was darker than bread produced with sole wheat bread. The color components (CIE L*a*b*) were shifted toward red and yellow. The bread containing spray-dried potato juice was also significantly richer in antioxidant compounds than the control wheat bread. From the perspective of consumer acceptance, the introduction of larger amounts of spray-dried potato juice resulted in deterioration of the sensory quality. Nonetheless, the acceptance of bread with 2.5% of flour substituted with spray-dried potato juice did not differ significantly from the control.
Keywords: Functional food; consumer acceptance; fermentation properties; food enrichment; texture.