BACKGROUND: The major whey protein β-lactoglobulin (BLG) has been widely studied for its functional properties. The aim of this study was to develop an efficient, inexpensive and rapid one-step method for the isolation and purification of BLG while preserving its native structure.
RESULTS: BLG was purified from defatted whey obtained from raw cow's milk by anion exchange chromatography. Protein purity and identity were determined using reverse phase high-performance liquid chromatography and mass spectrometry. Total BLG yield was 80% with protein purity from 97 to 99%. BLG isoforms A and B were separated into fractions of 91 and 99% purity respectively. The structure and native conformation of the isolated BLG were compared with those of standard commercial BLG by circular dichroism spectrometry, susceptibility to various crosslinking enzymes and enzyme-linked immunosorbent assay inhibition.
CONCLUSION: The proposed method is very useful for the rapid preparation of BLG suitable for studying antigenic and molecular characteristics of this protein, as well as the effect of food processing on these properties. The procedure requires only 1 day for the purification of about 300 mg of BLG from a single run using a small column (2.5 cm × 20 cm) of diethylaminoethyl Sephadex and has potential for scaling up. Copyright © 2011 Society of Chemical Industry