Use of Electro-Activated Whey as Ingredient in Fermented Milk Production: Proof of the Concept of the Technological Feasibility

Abstract

Alkaline electro-activation of whey was previously reported to convert 25–45% of lactose into lactulose. Neutralization after electro-activation did not cause the loss of the lactulose yield. Lactulose is an established prebiotic and is used as an additive in fermented dairy products. The aim of this work was to study the behavior of electro-activated whey used as an ingredient in a fermented milk. To carry out this study, prior to fermentation, milk (0, 1, 2, and 3% fat) was supplemented with 3, 6, and 9% electro-activated whey. Different analyses were performed such as acidification kinetic, textural, rheological, syneresis, organic acids production, sensorial, and microbiological parameters were assessed. Furthermore, the effect of electro-activated whey on the fermented milk microstructure was analyzed by scanning electron microscopy. The obtained results showed that the addition of electro-activated whey prolonged the time of fermentation. Samples with electro-activated whey had more homogeneous and less porous microstructure and were characterized by a significantly reduced syneresis compared to milk or whey supplemented milk. The presence of electro-activated whey did not hinder bacterial growth and triggered the superior production of organic acids such as lactic, acetic, citric, propionic, and butyric acids. The analysis of residual lactulose during refrigerated storage showed that approximately 50% of lactulose remained in the fermented milk, suggesting that the consumption of such product will provide a sufficient amount of lactulose reaching the host colon. Finally, this study clearly demonstrated the feasibility of using electro-activated whey as a lactulose-containing ingredient in fermented milk manufacturing.

Impact of electro-activated whey on growth, acid and bile resistance of Lacticaseibacillus rhamnosus GG and Lactobacillus acidophilus ATCC 4356

“…The electro-activated whey was prepared as follows: a 10% whey solution (w/w) was electro-activated in the cathodic side of an electro-activation reactor containing three compartments: anodic, cathodic, and central. The used electro-activation rector is made of a Plexiglas material and the central compartment is separated from the anodic and cathodic sides by anion and cation exchange membranes, respectively [ 7 ]. The central compartment was separated from the anodic and cathodic sides by anion and cation exchange membrane, respectively.…”

“…The whey solution was introduced in the cathodic compartment where reducing alkaline conditions were created while the other two compartments were filled with 0.1 M and 0.25 M K 2 SO 4 solutions to serve as electrolytes, respectively . After 60 min of electro-activation under a direct electric field of 800 mA, the electro-activated whey solution was kept for relaxation during 48 h at 22 ± 1 °C and then its pH was adjusted to 7 and freeze dried for further use [ 7 ]. Prior to use for bacterial growth, all the selected aqueous solutions of the growth media were filtered through sterile 0.45 μm and 0.2 μm filters.…”

“…Indeed, electro-activation of whey for lactose isomerisation into lactulose in carried out in the cathodic compartment of the electro-activation reactor where highly reducing conditions are created, leading to enhanced antioxidant capacity of the generated electro-activated whey [ 5 , 6 ]. Moreover, the technological feasibility of using electro-activated whey as an ingredient and source of lactulose in technological process of different fermented dairy beverages such as fermented milk, kefir and Ryazhenka production was demonstrated [ 7 , 8 ].…”

Whey Kefir: A Sustainable Solution to Reduce Waste and Improve Health

“…Various authors have used the different forms of whey to improve the overall processing and product characteristics of whey-based kefir. 17,82,84,85 Magalhaẽs et al used both cheese whey and deproteinized cheese whey as a base material and reported no significant difference between the end acetic acid, ethanol, and lactic acid content of the whey-based kefirs compared to milk based. 10,17 However, there were slight alterations in some volatile components like 2methyl-1-butanol, 1-propanol, but they all were under the threshold values.…”

“…92,93 Aidarbekova et al reported up to 40% conversion of lactose to lactulose using this method. 85 Lactulose is a prebiotic with high solubility and interesting technofunctionality. 92 Fermented dairy products supplemented with lactulose are beneficial in the treatment of constipation.…”