Caffè espresso, moka, napoletano e americano. Parte 2: simulazione dell’aroma retronasale. Indagine sull’influenza della saliva e del volume del sorso.

The influence of human saliva and sip volume on retronasal aroma release in coffee brew was studied. 24 aroma compounds of coffee brew were monitored and quantified in four different coffee brews (espresso, moka, Neapolitan and American). The four coffee brews showed a different partition of aroma compounds when coffee brew comes into contact with saliva, probably due to their different chemical composition. A significant influence of coffee sip volume on aroma headspace was also observed in espresso coffee. Particularly, an increase was obtained for some aldehydes assuming 25 mL coffee in one sip, while when smaller sips (10 mL) were considered, the aldehyde release decreased and the levels of b-damascenone and 4-vinylguaiacol increased. The different aroma release could not be attributed to direct action of salivary constituents, but rather to the modification of volatile partition into the different phases of coffee brew caused by the presence of saliva.