Figure 1.

Schematic representation proposed to explain sources of the target analytes under study (acids, alcohols, esters, monoterpenic compounds, norisoprenoids, sesquiterpenic compounds, sulfur compounds, and volatile phenols), taking into account that they can be formed from raw materials and/or produced and biotransformed along brewing, also the main associated metabolic pathways were highlighted (magnifying glass) [3,4,5,6,7,8,9,10]. MEP pathway: methylerythritol 4-phosphate pathway; MVA pathway: mevalonate pathway.