Context : During a meal, the flavor molecules of a food are released in the mouth by various mechanisms, then transported by saliva or air to stimulate chemoreceptors present in the mouth or nasal cavity. Studies have shown that the oral microbiota has an important role in flavor perception.Enzymes in the oral microbiota have the ability to generate volatile aroma molecules with different sensory properties than their non-volatile precursors. Interestingly, thesereactions also occur during certain fermentation processes (Schwartz et al., 2021).Microbial enzymes called Carbon-Sulfur Lyases (CSLs) metabolize cysteine ​​conjugates, leading to the formation of molecules bearing a free thiol function with odorous properties and low retronasal perception thresholds. It has been shown that the enzymatic release of sulfur volatiles in the mouth is correlated with an aversion to certain foods (Frank et al, 2021). Thus, it is important to better understand these enzymatic mechanisms influencing our perception of aromas when consuming a meal in order to propose new strategies to improve the flavor of foods containing aromatic precursors.