Foam fractionation technology for enrichment and recovery of cheese whey proteins

Foam fractionation technology works on the adsorptive bubble separation principle. This technique involves adsorption of the surface-active substances on to a gas-liquid interface and separation of these components from the liquid along with bubbles as foam. The foam separation technology has been successfully utilized in the recovery of proteins from solutions containing either a single protein or binary mixtures. To develop a foam fractionation technology for selective enrichment and recovery of whey proteins, it is essential to investigate the effect of different feed and process variables that affect the foam fractionation process. The aim of the current study was to investigate the effect of two important feed variables, such as pH and initial protein concentration on recovery and enrichment of total whey proteins as well as α-lactalbumin and β-lactoglobulin.

All the experiments were conducted in Agriculture and biosystems engineering lab and Alfred Dairy Science lab at South Dakota State University, Brookings, South Dakota during 2011-2013. The experiments used four levels of initial protein concentration and five levels of feed pH. Yield and enrichment ratios were determined for total whey proteins, α-Lactalbumin (α-La) and α-Lactoglobulin (β-Lg).

Whey protein yields ranged from 51.58 to 90.92%, while the enrichment ratios were between 1.2 to 5. The yield of α-La varied from 59 to 94% and the highest enrichment ratio of 8.45 was obtained with the treatment combination of initial protein concentration of 109 mg/L and pH of 5.1. Selective enrichment of α-La over β-Lg was observed at a pH of 4.65 with α-La to β-Lg ratio of 0.49. These findings will be helpful in selective enrichment and recovery of valuable proteins from Cheddar cheese whey using the foam fractionation process.