Studies on the Elimination of β-lactoglobulin from Whey Using Carboxymethyl Cellulose Cation Exchanger

Effects of pH and Desalting of Whey on the Fractionation of β-lactoglobulin

Abstract

The effects of pH and desalting on the elimination of β-lactoglobulin (β-LG) from bovine whey by using carboxymethyl cellulose (CMC) cation exchanger were investigated. Desalting of whey enhanced the amount of adsorbed β-LG on CMC cation exchanger. However, excess desalting, i. e. more than 90% as conductivity, reduced the selective adsorption of β-LG to CMC cation exchanger. Selective adsorption of β-LG on CMC cation exchanger conld be performed at pH 4.6 in the case of using the whey which was dialysed for 48h. If the pH of whey was lower than 4.0, not only β-LG but also other proteins, for example, α-lactalbumin (a-LA), bovine serum albumin (BSA) and immunoglobulin (lgs), were adsorbed on CMC cation exchanger. On the other hand, if the pH was higher than 5.0, major whey proteins containing β-LG could not be adsorbed on CMC cation exchanger. We could obtain two types of freeze-dried whey protein fractions. One is β-LG eliminated whey powder which showed good solubility and heat stability, and the other is β-LG rich whey protein isolate.β-LG accounted for less than 20% of major proteins in the β-LG eliminated fraction, while more than 90% of major proteins in the β-LG rich fraction.