Capturing whey proteins from milk whey using an ionic liquid-based magnetic adsorbent

Whey proteins are important source of bioactive peptides, which can present antioxidant, anti-hypertensive, and antimicrobial activities among other effects. Indeed, whey proteins have valuable nutritional importance, including potential immunological and antiviral related effects. However, to design protein formulations for a target application its extraction and purification is essential. In this context, the ionic liquid (IL) technology combined with the magnetic nanotechnology may constitute an interesting sustainable alternative. In this work, a magnetic IL-based adsorbent (MNPs-IL-Ni²⁺) was produced and its ability for capturing whey proteins was investigated. The impact of pH, temperature, and NaCl concentration on protein adsorption was systematically evaluated using bovine serum albumin (BSA) as a model protein and the magnetic IL-based adsorbent (MNPs-IL-Ni2+) through a design of experiments (DoE) approach. Then, whey proteins were recovered from milk whey under fixed process conditions. A second order model was adjusted with coefficient of determination of 94.51 %. Increasing of temperature and NaCl concentration affected positively protein adsorption. Otherwise, pH values lower than 5 were more favorable to the protein adsorption. Interestingly, alpha-lactalbumin (α-LA), beta-lactoglobulin (β-LG), immunoglobulin (IgG), BSA and lactoferrin (LF) were recovered from milk whey by using IL-based adsorbent, which was evidenced by SDS-PAGE analysis. Therefore, the IL-based adsorbent is a promising tool for whey protein extraction and has high potential application in the agri-food industry.