The research of whey permeate mineral profile at different stages of membrane filtration

Abstract

Whey permeate powder is widely used in technologies of various line groups of food products, but the main limiting factor of its application is its high ash content. This research aimed to establish the efficiency of ash reduction and change of mineral profile at various stages of production for obtaining demineralized whey permeate powder suitable for further usage in technologies of lactose. The experiments were carried out following the referee method and the common methods used in research practice. The objects of research were cheese whey and its concentrate and permeate obtained in the process of ultrafiltration (UF), nanofiltration (NF), electrodialysis (ED), vacuum-evaporating and spray drying. UF made it possible to remove partially Ca2+, total phosphorus, and Mg2+ from cheese whey, NF was effective in removing part of K+, Ca2+, Fe2+, Mg2+, Cu2+, Cl- and total phosphorus from UF-permeate. Using polymer membranes made it possible to obtain the NF-concentrate containing mainly lactose and increase the efficiency of ED due to their high permeability relative to water, as well as their ability to eliminate proteins and partially some ions of mineral salts. The mass fraction of ash in the finished product decreased by 93.0% compared with cheese whey, as well as Na+ and K+ by 89-94%, and Ca2+ and Mg2+ by 60-75%; the total phosphorus – by 78%; chlorides – by 70%. The obtained results allow to justify the technological operation sequence to produce a product suitable for further usage as a raw material for highly purified lactose.