An in vitro gastric digestion of heat-induced aggregates of β-lactoglobulin (β-lg) in simulated
gastric fluid was investigated using sodium dodecyl sulfate-PAGE under nonreducing and
reducing conditions, native-PAGE, 2-dimensional electrophoresis, and size exclusion
chromatography. Heating at 90ºC significantly increased the digestibility of β-lg, with a high
initial digestion rate followed by a relatively constant rate of digestion at a high
enzyme:substrate (E:S) ratio of 3:1. At a low E:S ratio (1:6), the rate of digestion of β-lg was
slower, and intermediate and low molecular weight species could be seen. The high
molecular weight nonnative aggregates (pentamers, tetramers, trimers, etc.) were digested
relatively rapidly, whereas some of the nonnative dimers were resistant to digestion and
others were digested rapidly. The intermediate molecular weight species (21 to 23 kDa) were
digested slowly. These results indicated that the digestibility of nonnative β-lg aggregates
varied significantly depending on the E:S ratio and the types of aggregate. Further
investigation is necessary to identify and characterize slowly digested dimers and
intermediate molecular weight species.
Peram, M. R., Loveday, S. M., Ye, A., & Singh, H. (2012). In vitro gastric digestion of heatinduced aggregates of β-lactoglobulin. Journal of Dairy Science, 96, 63-74.
NOTICE: this is the author’s version of a work that was accepted for publication in the Journal of Dairy Science. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version is published in Journal of Dairy Science [96,1 (2013) http://dx.doi.org/10.3168/jds.2012-5896 ]