Apple juice stabilization by combined enzyme-membrane filtration process

Abstract

Stabilization against discolouration and clouding is a major problem in fruit juice production. Effects of enzymatic oxidation of polyphenols, associated with ’active filtration ’ and membrane filtration were evaluated, in terms of juice characteristics and stability. Laccase oxidation produces a significant decrease in the phenolic content of juices, associated with a remarkable colour increase. Active filtration by polyvinylpolypyrrolidone and activated charcoal partially decolourates the oxidized juices and stabilizes these products, removing a high quantity of phenolic compounds. Membrane filtration demonstrates to be an effective technique in terms of stabilization only if performed using low molecular weight cut-off membranes. © 1993 Academic Press. All rights reserved.