Impact of Variety and Agronomic Factors on Crude Protein and Total Lysine in Chicory; N ε‑Carboxymethyl-lysine-Forming Potential during Drying and Roasting

During the heat treatment of coffee and its substitutes some compounds potentially deleterious to health are synthesized by the Maillard reaction. Among these, N ε-carboxymethyl-lysine (CML) was detected at high levels in coffee substitutes. The objective of this study was to evaluate the impact of changes in agricultural practice on the lysine content present in chicory roots and try to limit CML formation during roasting. Of the 24 varieties analyzed, small variations in lysine content were observed, 213 ± 8 mg/100 g dry matter (DM). The formation of lysine tested in five commercial varieties was affected by the nitrogen treatment with mean levels of 176 ± 2 mg/100 g DM when no fertilizer was added and 217 ± 7 mg/100 g DM with a nitrogen supply of 120 kg/ha. The lysine content of fresh roots was significantly correlated to the concentration of CML formed in roasted roots (r = 0.51; p < 0.0001; n = 76).