Maillard reaction products in plant-based dairy alternatives and their release during simulated gastrointestinal digestion

Plant-based food products are becoming increasingly popular among consumers. The chemical composition and the processing of plant-based products presumably fuel the Maillard reaction, but the abundance of Maillard reaction products in plant-based food products is rarely investigated. In this study, the concentration of N-ε-carboxymethyllysine (CML), N-ε-carboxyethyllysine (CEL) and methylglyoxal-hydroimidazolone (MG-H1) was analyzed with UPLC-MS/MS in six plant-based dairy alternatives. Total amounts of free and protein-bound glycation compounds ranged from 0.03 to 0.31 mg/100 g food for CML, 0.04–1.28 mg/100 g food for CEL and 0.69–2.84 mg/100 g food for MG-H1. Free glycation compounds were abundant in yogurt and cheese, but not milk alternatives. During simulated gastrointestinal digestion, CML and MG-H1 were released either as modified amino acid or in peptide-bound form, respectively. CEL was released to a significantly lesser extent in peptide-bound form. For CML, de novo formation of up to 400 % during digestion was observed. The results showed that Maillard reaction products are quantitatively important process-induced compounds in plant-based food products which are available after digestion.