Regulation of milk protein solubility by a whey-derived proline-rich peptide product


The effects of a bovine whey peptide product enriched in proline (wPRP) on the solubility of milk proteins were tested under ambient conditions or following heat treatment at 75 and 100Â °C, for 1 and 15Â min, followed by post-incubation storage at either ambient temperature or 4Â °C for up to 7Â d. wPRP promoted solubilisation of milk proteins in a concentration-dependent manner without heat treatment and also after heat treatment at 75 and 100Â °C, and the effect was enhanced after storage under either ambient or refrigerated storage conditions. Interactions of wPRP and milk proteins were monitored by particle size analysis and tryptic digestion and specifically linked with solubilisation of αS1 casein (αS1-Cn), which supported observed changes in milk protein solubility. The results suggested that wPRP preferably prevented or reversed physical versus covalent protein aggregation, with the relaxation of hydrophobic interactions at 4Â °C providing an additive effect. This application of wPRP represents a novel approach to stabilisation of dairy proteins following thermal processing with industrial usefulness yet to be explored. Copyright © Proprietors of Journal of Dairy Research 2013Â.

Publication Title

Journal of Dairy Research