Saltiness can be modulated by the aerosol generation behavior of salt solution

Odor-induced saltiness enhancement is an effective strategy in reducing salt usage of foods, making the aroma transfer a saltiness-related factor during food consumption; yet the contribution of aerosol-mediated retro-nasal delivery is underexplored. Aerosol droplets are well-recognized as carriers of aroma compounds, and their generation can be sensitively influenced by salt content. Therefore, this study aimed to quantitatively evaluate aerosol generation from salt solutions within their typical food applications, as well as the resulting release and perception of four representative aroma compounds known to enhance saltiness using both trained ( n  = 10) and untrained ( n  = 40) subjects. As main results, NaCl was approved to significantly increase aerosol numbers and mass contents than pure water at the in-vitro tests (up to ∼110 fold, p  < 0.05). Aroma compounds, congruent with saltiness, and with higher hydrophilicity (3-(methylthio) propanal and 2,5-dimethylpyrazine) or lower volatility (2-ethyl-3,5-dimethylpyrazine) were more prone to be transferred via aerosol. In contrast, the release of aroma compounds with hydrophobic and high volatility (dimethyl trisulfide), was primarily governed by molecular diffusion. Significant correlations were observed between the release content of aroma compounds and aerosol numbers ( p  < 0.05). The aerosol-induced olfaction was approved via the sensory tests (dual reminder A-not A test and 15-cm linear scale), and the resulted saltiness intensity was depended on the aroma concentration. This is the first study to demonstrate that both aroma release and odor-induced saltiness enhancement can be modulated by presence of aerosol droplets, which is also sensitively affected by the salt content.