New approach to continuous vinegar decolourisation with exchange resins

A decolourisation process using ion-exchange resins (Lewatit S-5328-A) was applied to wine vinegar on a pilot scale. In the fixed experimental conditions, the decolourisation efficiency (DE) was 75.5% and the total phenolic compounds removed (DPTI) was 60%. Additional analysis of the adsorption selectivity of the ion exchange showed that the phenolic fraction involved in browning decreased. The resin had a greater affinity for the hydroxycinnamic acids (99% removed), (+) catechin and gallic acid (both 85% removed). Vinegar colour enhancement was also conducted. The colour of a browned vinegar improved to normal values after the adsorption process.