Fractions enriched with α-lactalbumin (α-la) and β-lactoglobulin
(β-lg) were produced by a process comprising the following successive steps:
clarification–defatting of whey protein concentrate, precipitation of α-lactalbumin,
separation of soluble β-lactoglobulin, washing the precipitate, solubilization of the
precipitate, concentration and purification of α-la. The present study evaluated the
performance of the process, firstly on a laboratory scale with acid whey and then on
a pilot scale with Gouda cheese whey. In both cases soluble β-lg was separated from
the precipitate using diafiltration or microfiltration and the
purities of α-la and β-lg were in the range 52–83 and 85–94%
respectively. The purity of the β-lg fraction was
higher using acid whey, which does not contain caseinomacropeptide, than using
sweet whey. With the pilot scale plant, the recoveries (6% for α-la; 51% for β-lg)
were disappointing, but ways of improving each step in the process are discussed.