Exploring the Effect of Ultrafiltration/Diafiltration Processing Conditions on the Lactoferrin and Immunoglobulin G Content of Feta Whey Protein Concentrates

In this paper, the production of powder enriched in lactoferrin (Lf) and immunoglobulin G (IgG) from untreated feta cheese whey is studied. More specifically, the influence of transmembrane pressure (Δp) and temperature on flux and separation ability during ultrafiltration combined with continuous diafiltration is investigated. Two different types of membranes were used, a spiral polyvinylidene fluoride (PVDF) (molecular weight cut-off [MWCO 75 kDa) and a set of 18 cylindrical PVDF membranes (MWCO 100 kDa). For the production of the whey powder, two drying methods were compared: spray and freeze drying. All combinations lead to powder with high total protein content and with a notable content in these two bioactive proteins. However, cylindrical membranes (at a temperature of 20C and a transmembrane pressure of 4 bar) in combination with freeze drying resulted in the highest yield from whey into Lf and IgG and excellent sensory characteristics. Practical Applications Whey powder enriched in the multifunctional proteins lactoferrin and immunoglobulin G have very large potential both as nutrition additives and for pharmaceutical purposes. The systematic study of the parameters affecting all unit operations involved leads to the most efficient and cheapest production. In order to achieve this, the methodology was kept as simple and low cost as possible. This way, a strong tool could be created for the utilization of the cheese-making by-product whey, which still causes large environmental problems.