Production of rectified grape musts by ion exclusion chromatography

Traditionally, rectified grape musts were produced by passing the clarified juice over a series of cation and anion exchange resins to remove salts, organic acids and nitrogenous materials. This process has lower productivity and causes environmental issues due to the requirements of regenerating ion exchangers. In order to solve these problems, a new process for the production of rectified concentrated grape musts from grape juice was proposed. Instead of using conventional refining processes, e.g., ion exchange-based method, rectified grape musts could be simply produced in a single step of ion exclusion chromatography. The effect of flow rate and loaded volume of feed on the separation performance was investigated. Grape sugars were easily separated from inorganic salts as well as organic acids. High purity (more than 99.9%) of rectified must was obtained with high recovery yield (approximately 99.0%). Organic acids were not detected in the rectified must while total content of inorganic ions was lower than 0.70 g/kg of total sugars. The amount of total polyphenolic compounds varied from 47.1 to 104.7 mg/kg total sugar (as mg of gallic acid equivalent). However, the effect of cations other than potassium on the separation performance requires a long-time investigation.