The impact of the Maillard reaction on the in vitro proteolytic breakdown of bovine lactoferrin in adults and infants

Abstract

The Maillard reaction has been proposed as a natural pathway to functionalize proteins and modulate their proteolysis. Nevertheless, gaps in understanding the digestive fate of Maillard reaction products (MRPs) still exist, especially regarding bioactive proteins such as lactoferrin (LF). UV absorbance and SDS-PAGE were used to monitor reaction progression under mild thermal processing (60 °C, 79% RH). Dynamic light scattering showed that MRPs had increased colloidal size and turbidity at 3 < pH < 10. FRAP analysis and in vitro digestion experiments demonstrated that MRPs possessed improved antioxidant capacity and higher susceptibility to proteolysis to varying extents under adult conditions compared to infant conditions. Proteomic analyses of MRP digesta revealed altered enzymatic cleavage patterns with no pronounced changes in the formation of known bioactive peptides. These also indicated that MRPs may breakdown in the gastro-intestinal tract to potentially form novel bioactive peptides. Overall, this work highlights that the Maillard reaction could be harnessed to modify the extent of proteolysis and bioactivity of proteins.