Separation of monoglycosides from fruit juice by diafiltration

The process of separating sugars from anthocyanins in black currant juice has been investigated. Diafiltration on a laboratory scale flat sheet module (Labstk M20, Alfa Laval Nakskov A/S, Denmark) loaded with an ultrafiltration membrane (ETNA01-PP, MWCO = 1,000 Da, Alfa Laval Nakskov A/S, Denmark) with a total installed area of 0.25 squaremeters distributed on 14 sheets showed good retention of anthocyanins as compared to fructose and glucose. In order to investigate whether the different flow pattern in a commercial size module would affect separation experiments were conducted with the same membrane in a 4'' spiral wound module. As the retention were mainained for anthocyanins, fructose and glucose the process have been demonstrated to be viable for scale up.