Study on the Extent of the Maillard Reaction in Chocolate

During chocolate production, thermal processes such as roasting and conching promote nonenzymatic browning reactions such as the Maillard reaction and caramelization. In the present work, the MRPs furosine, 3-deoxyglucosone (3-DG), 3-deoxygalactosone (3-DGal), 5-hydroxymethylfurfural (HMF), <i>N</i>-ε-fructosyllysine, <i>N</i>-ε-lactulosyllysine, <i>N</i>-ε-carboxymethyllysine (CML), <i>N</i>-ε-carboxyethyllysine (CEL), pyrraline, methylglyoxal-derived hydroimidazolone 1 (MG-H1), formyline, maltosine, and rhamnolysine were quantitated in 4 filled, 12 dark, 11 milk, and 4 white chocolate samples. The predominant MRP in filled chocolates was <i>N</i>-ε-fructosyllysine (up to 2662 mg/kg of chocolate), whereas in milk chocolates, it was <i>N</i>-ε-lactulosyllysine (up to 883 mg/kg of chocolate). Filled and milk chocolates contain higher levels of furosine and CML. Dark and white chocolates exhibit lower levels of MRPs such as furosine, CML, CEL, and formyline. The consumption of milk chocolates and filled chocolates can contribute significantly to the dietary intake of pyrraline, <i>N</i>-ε-fructosyllysine, <i>N</i>-ε-lactulosyllysine, and CML.