Abstract:

Astringency is a complex sensation mainly caused by the precipitation of salivary proteins with polyphenols. In
wine, astringency can be enhanced or reduced depending on the compositions of the medium. Reduced proportion of human
saliva protein after reaction with model wine was evaluated by sodium dodecyl sulfate polyacrylamide gel (SDS-PAGE),
and expressed as astringency intensity. Furthermore, the effects of three parameters including ethanol, total acid, pH, and
drinking temperature on astringency intensity were studied by quadratic orthogonal rotation combination analysis. The
results showed that pH had the greatest influence on astringency, followed by total acid and temperature, while ethanol had
little impact on astringency. The effect of interaction between pH and total acid was significant.

Key words: model wine, sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), astringency intensity, saliva precipitation index