In-Depth Exploration of 2,5-Dimethylpyrazine in Traditional Charcoal-Grilled Lamb: A Study Using Food and Model Reaction Systems and Density Functional Theory

Abstract

Charcoal-grilled lamb is prized for its rich roasted and nutty aromas, primarily driven by 2,5-dimethylpyrazine (2,5-DMP). This study explored the formation and reactivity of 2,5-DMP in the grilled lamb using food and model reaction systems integrated with density functional theory (DFT). A total of 36 aroma compounds were identified during grilling. The 2,5-DMP concentration peaked at 25 min, strongly correlating with significant reductions in glucose and glycine levels. The model reaction systems confirmed glycine and glucose as primary precursors, producing 339.51 ng of 2,5-DMP. The DFT analysis identified glucose’s C5-OH group and glycine’s -NH2 group as key reactive sites, facilitating the nucleophilic and electrophilic interactions. It revealed low activation energy and high reactivity, elucidating the reaction pathway involving nucleophilic substitution, dehydration, and condensation. This study provides novel insights into 2,5-DMP formation mechanisms and offers a foundation for optimizing grilling processes to enhance the aroma and sensory quality of meat products.

Keywords: grilled lamb, 2, 5-dimethylpyrazine, roasty aroma, model reaction system, Maillard reaction, density functional theory