The
interaction between phenolic compounds and salivary proteins
is considered the basis of the poorly understood phenomenon of astringency.
Furthermore, this interaction is an important factor in relation to
their bioavailability. In this work, interactions between anthocyanin
and human salivary protein fraction were studied by mass spectrometry
(MALDI-TOF-MS and FIA-ESI-MS) and saturation-transfer difference (STD)
NMR spectroscopy. Anthocyanins were able to interact with saliva proteins.
The dissociation constant (<i>K</i><sub>D</sub>) between
malvidin 3-glucoside and salivary proline-rich proteins was 1.92 mM
for the hemiketal form (pH 3.4) and 1.83 mM for the flavylium cation
(pH 1.0). New soluble complexes between these salivary proteins and
malvidin 3-glucoside were identified for the first time