Heat Denaturation of Bovine β-Lactoglobulins and Relevance of Disulfide Aggregation

Abstract

The primary and secondary stages of the heat denaturation of bovine β-lactoglobulin A have been examined using starch gel electrophoresis and sedimentation velocity techniques. The primary reaction results in the formation of a series of molecular aggregates through the establishment of intermolecular disulfide bonds. A much heavier component is formed during the secondary reaction, but disulfide bonds are not involved in its formation. The results of turbidity experiments indicated that the susceptibility of the genetic variants of β-lactoglobulin to heat denaturation is in the order β—C>β—B>β—A. The relative importance of the formation of disulfide bonds during the aggregation of each variant is discussed. A mechanism describing the behavior during heat treatment is presented. © 1968, American Dairy Science Association. All rights reserved.