L-cysteine modulates the Maillard reaction: Impacts on PhIP and pyrazine formation

L-Cysteine (L-Cys) serves as both an inhibitor of the carcinogen 1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and an enhancer of food flavor, supporting efforts to improve food safety and quality. Using a glucose/phenylalanine/creatinine model system, this study assessed the effects of varying L-Cys concentrations on PhIP inhibition and pyrazine flavor enhancement through UPLC–MS/MS and GC–MS analyses. The optimal PhIP reduction (82.8 %–83.1 %) was achieved with 20 mg and 100 mg of L-Cys, whereas the pyrazine enhancement peaked with 200 mg and 100 mg of L-Cys (50.54 %–99.16 % and 37.83 %–98.82 %, respectively). A partial least squares regression (PLS) model demonstrated strong predictive accuracy (R2c and R2p > 0.73), providing a robust framework for regulating PhIP and pyrazine levels. This study offers a theoretical basis for advancing food safety and flavor quality, contributing to the development of safer and more enjoyable food products while addressing health and sustainability considerations.