Influence of the tannin structure on the disruption effect of carbohydrates on protein–tannin aggregates

The disrupting effect of three different ionic carbohydrates (xanthan, pectin and gum arabic) on the formation of tannin–protein insoluble aggregates was assessed by nephelometry using bovine serum albumin (BSA) and several procyanidin fractions previously extracted from grape seeds. The presence in solution of any of the carbohydrates studied was found to restrain the formation of insoluble protein–tannin aggregates for every procyanidin fraction used. Xanthan was the most effective carbohydrate, whereas gum arabic was the least effective. The present work has revealed that the disrupting effect of carbohydrates is quite different depending on the procyanidin structure complexity. In general, the three carbohydrates studied revealed a similar trend in that their disrupting effect on tannin–BSA aggregate formation decreased with increase of the procyanidin degree of polymerization.