Stimulation of saliva affects the release of aroma in wine; a study of microbiota, biochemistry and participant origin

Saliva influences the release of aroma in the oral cavity. The composition of human saliva varies depending on stimulation and hosts origin; however, the compositional differences of saliva and their influences on aroma release have not been fully evaluated. In this study, we recruited 30 healthy adults (15 Australians and 15 Chinese) and collected saliva samples at three stages: before, during, and after stimulation. Salivary samples were characterised by flow rate, total protein concentration, esterase activity, microbiome composition by full-length 16S rRNA gene sequencing, and the ability to release aroma from wine by headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS). Differences in salivary composition and specific wine volatiles were found between Australian and Chinese participants, and amongst the three stimulation stages. Significant correlations between the relative abundance of 3 bacterial species and 10 wine volatiles were observed. Our results confirm the influence of participants geographic origin and stimulation on salivary composition, highlighting the role of salivary components, especially salivary bacteria, on the release of aroma from wine.