SELECTIVE REMOVAL OF IRON FROM GRAPE JUICE USING AN IRON(III) CHELATING RESIN

This work reports the results of iron removal from grape juice with an iron(III) chelating resin in both batch separation and column separat ion processes. The separation experiments indicated that the iron(III) chelating resin removed iron selectively and effectively from grape j uice. The iron content in grape juice was reduced from 1000 ppb to 2 p pb with a batch separation at a ratio of 1 g of the resin to 100 ml of grape juice. By using a sequential multi-batch separation process or a column separation process, the iron level in grape juice could be re duced to 1 ppb with the iron(III) chelating resin. It was found that s elective removal of iron was completed within 3 h. The chelating resin did not remove other metals such as Co, Mg, Ca, Zn, Mn, K and Na in t he grape juice. Mo and Cu, however, were partially removed. Preliminar y microbial tests indicated that the growth of the wine yeast (Sacchar omyces cerevisiae) was partially inhibited in the iron-deficient grape juice. (C) 1997 Elsevier Science B.V.