Maillard induced saccharide degradation and its effects on protein glycation and aggregation

Abstract

Saccharides are known to influence the maximum Maillard degree of glycation (DGmax) and protein aggregation reached. This research focused on the link between the fate of saccharide content, saccharide degradation and Maillard glycation and aggregation. Heat-treatment of α-lactalbumin with surplus glucose, maltotriose and galacturonic acid resulted in a DGmax lower than 100% (88, 21 and 57% for AG, AMtt and AGalA). Saccharide content still decreased after DG had plateaued and after 48 h enough saccharide was still present to further increase the DG of all samples, to 100% in AG/AMtt or to 85% in AGalA. Up to 17, 12 and 24% of the saccharide carbon in AG, AMtt and AGalA degraded to organic acids (e.g. acetic, formic, lactic, glycolic and succinic acid). Acetic and formic acid were the most abundant organic acids in all samples. Lactic acid was only identified in samples containing Maillard aggregation (AG and AGalA), and likely derives from the degradation of excess methylglyoxal, a protein cross-linking agent formed during the Maillard reaction.

Keywords

• α-lactalbumin
• Maillard
• Aggregation
• Degradation
• Saccharides
• Organic acids