METHOD FOR BLEACHING FRUIT JUICES AND ACTIVATING THE BLEACHING ADSORPTION RESINS BY ORGANIC ACIDS BEING IN FRUIT JUICE

摘要

Clarified and polished fruit juices are decolourised by passing them through columns of adsorbent resins. Decolourising is continued until the absorption value of the colour of the fruit juice remains within 40% of its initial level, thus satisfying predetermd. requirements. When this value is exceeded, the flow of fruit juices is stopped and having displaced juices remaining in the column by water, the column is regenerated. For this purpose the column is eluted by an alkaline soln. followed by a water rinse, until the effluent pH falls below 11. Organic acids present in the fruit juices are used for reactivation of the resin. For this, fruit juices of pH below 4 are passed through the column until the pH of the effluent falls below 5, and the initial absorption value is re-established. - Decolourising and regeneration is subsequently repeated when reqd. Decolourised fruit juice batches are pref. collected in the same holding vessel.