Cocoa protein crosslinking using Maillard chemistry

Protein crosslinking via the Maillard reaction has been shown to alter the functional properties of several food proteins, but the potential to use this chemistry to alter the functional performance of cocoa proteins has yet to be fully explored. This study investigated the potential of employing cocoa protein crosslinking during processing. Cocoa protein solutions were extracted from dried cocoa beans and the resulting cocoa protein solutions were treated with 2–300 mM glutaraldehyde and methylglyoxal, which established model compounds for Maillard crosslinking chemistry. SDS–PAGE analysis showed remarkably few crosslinks of the cocoa protein solutions, although lysine and particularly arginine availability were both reduced during the incubations. These results suggest that cocoa proteins are not greatly susceptible to intermolecular cross-linking via Maillard chemistry, perhaps due to non-cross-linking modifications to the arginine residues, and/or to interference from high levels of polyphenols in the cocoa bean.