Impact of the Drying Agents Maltodextrin and Gelatin Used in Whey Powders on the Quality Characteristics of Yogurt

Abstract

Drying agents used in the process of spray drying whey enhance the quality of whey powders and may consequently improve the properties of yogurts to which these powders are added. This study examined the quality characteristics of yogurts enriched with whey powders using maltodextrin or gelatin as drying agents. The following yogurt variants were produced: a control (C) without whey powder; W with whey powder but without a drying agent; M with whey powder containing maltodextrin; and G with gelatin as a drying agent. Whey powders were added at a concentration of 1.5% (w/w). The samples were tested after 3, 6, 10 and 14 days of refrigerated storage (4 ± 1 °C), and analyses were performed in 3–6 repetitions. Enrichment of milk with powdered whey had a noticeable impact on the quality characteristics of yogurts. Fortified yogurts exhibited a significantly higher total solids content (11.43–12.22% in the control; 12.45–13.33% in W, G and M) and higher acetaldehyde concentration (0.31–1.11 ppm in the control; 0.44–1.82 ppm in W, G and M) than the control. Titratable acidity and pH varied among samples. However, the syneresis index was lower in the control yogurt (39.09–46.74%) than in yogurts with powdered whey (53.71–58.48%). Significant differences were observed in color parameters (L, a*, b*, WI, YI). The texture properties (firmness, consistency, cohesiveness, index of viscosity) of samples with whey powders had higher values than the control. In sensory evaluation, yogurts with whey powders obtained high scores. The study demonstrated that the use of maltodextrin or gelatin not only supports the process of spray drying whey but also alters the characteristics of the resulting yogurts. The impact of the study comes from the fact that it bridges the gap between whey processing (spray drying) and the formulation of the final product.