Compositional variability in commercial tannin and mannoprotein products

Abstract

Enotannin and mannoprotein additives are applied to achieve protein, cold, or color stability in wine, or to modify wine sensory properties. In most cases, the manufacturer only provides basic compositional information and a proposed effect in wine. In this study, 14 grape-based enotannins and eight mannoproteins were sourced from the Australian market, and their composition and molecular size distribution were determined. Diverse product composition was observed for both categories, suggesting that a range of effects could potentially be achieved by applying different products. Moreover, some products showed good agreement between product composition and their designated material of origin, while others showed significant differences.