The present work deals with selected aspects of protein modification by α-dicarbonyl compounds. These reactions belong to the field of non-enzymatic browning and play an important role in production and processing of foods and in the development of diseases under physiological conditions. The underlying mechanistic pathways are essential for the comprehensive assessment of these reactions. Because of that, the aim of this work was the mechanistic investigation of the modification of amino acid side chains by highly reactive α-dicarbonyls. Furthermore, protein modifications were used to characterize the process of food production. The targeted reaction of α-dicarbonyls with proteins for improved functional properties was an additional part of this dissertation.