Dairy-Derived Aroma Release Modulated by Oral Mucin: In Vitro Study Insights from Multispectral, Computational Modeling, and Machine Learning

Salivary mucin plays a pivotal role in modulating aroma perception during dairy consumption. This study investigated the impact of mucin on the release of ten key milk fat-derived aroma compounds (including 3 aldehydes, 3 ketones, and 4 lactones) using headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). The results demonstrated that mucin significantly inhibited the release of most compounds, including 2-heptanone, 2-nonanone, 2-pentadecanone, heptanal, δ-hexalactone, δ-octalactone, and δ-decalactone, with a maximum binding percentage of 34.79 ± 9.63%. Sensory analysis confirmed perceptible differences. Thermodynamic and spectroscopic data revealed that the binding was spontaneous and primarily driven by hydrophobic interactions and hydrogen bonds involving phenylalanine and tyrosine residues, which induced significant conformational changes in the mucin secondary structure. Shapley additive explanations analysis based on the support vector regression model identified the number of H-bond acceptors as the most critical molecular feature. These findings provide insights for modulating aroma perception in dairy products.