ALPHA-LACTALBUMIN ENHANCES THE GELATION PROPERTIES OF BOVINE SERUM-ALBUMIN

The effects of addition of alpha-lactalbumin (alpha-La) to bovine serum albumin (BSA) on gelling properties were investigated. A BSA concentration of 4% (w/v) was required for formation of a self-supporting gel following heating at 80-degrees-C for 30 min in 100 mM sodium phosphate buffer (pH 6.8). Solutions of alpha-La, even up to a protein concentration of 8% (w/v), did not gel under the same conditions. The addition of 3% alpha-La to 6% BSA caused a significant increase in gel hardness, and the gels thus obtained were transparent. BSA and alpha-La interacted to form soluble aggregates through thiol-disulfide interchange reaction during gel formation. The soluble aggregates formed during heating of the mixture of BSA and alpha-La had lower molecular weights than those formed from BSA alone. The enhancing effect of alpha-La on gel hardness of BSA was ascribed to the formation of a finer, more uniform gel matrix.