Influence of the addition of grape seed procyanidins to Port wines in the resulting reactivity with human salivary proteins

The tannin specific activity of several Port wines was evaluated through the reaction with bovine serum albumin (BSA) and two groups of previously extracted human salivary proteins: α-amylase and proline-rich proteins. The wine reactivity towards BSA and salivary proteins was studied by nephelometry. The tannin specific activity of the wine increased progressively with incremental addition of grape seed procyanidins. α-Amylase was shown to be the best protein to distinguish wines containing different amounts of procyanidins regarding their polyphenol reactivity.