Production of Ryazhenka, a traditional Ukrainian fermented baked milk, by using electro-activated whey as supplementing ingredient and source of lactulose

Abstract

In this work, electro-activated whey (EAW) was used as ingredient in the preparation of Ryazhenka, a fermented baked milk, at a supplementation level of 3 and 9%. Fermentation kinetics, viscosity, color, antioxidant capacity, and protein profiles of the final product were studied. Moreover, effect of electro-activation on β-lactoglobulin allergenicity was evaluated by a specific ELISA test. The results showed that addition of electro-activated whey as supplementing ingredient is technologically feasible in the process of Ryazhenka production. The fermentation kinetics showed that this process was in the technologically accepted interval even if the addition of EAW delayed the fermentation phase. The viscosity study showed that addition of EAW permitted to obtain a final product with good followability corresponding to good consistency of drinkable dairy beverages. Moreover, addition of EAW prevented syneresis during the refrigerated storage at 4 °C and enriched the product with lactulose which is a recognized prebiotic. The chromatic evaluation of the final product showed a compatibility of EAW with Ryazhenka which is known for its specific yellowish-brownish color. Addition or EAW significantly improved the antioxidant capacity of the Ryazhenka with values of IC50DPPH = 2.54 ± 0.02 and IC50PFRAP = 244.03 ± 28.83 for the Ryazhenka produced by adding 9% EAW to the milk after the baking process and prior to fermentation. Moreover, by using a β-lactoglobulin specific ELISA test, this study showed a significant decrease of whey and pure β-lactoglobulin allergenicity by 95%. This decrease was also observed in Ryazhenka supplemented with 9% EAW but at lower level. Thus, it can be concluded that electro-activated whey can be considered as a promising functional ingredient containing a prebiotic lactulose as functional ingredient in the dairy industry.