Isolation, purification and characterization of neutral polysaccharides from extracted apple juices

Abstract

Using membrane processes, the pectic material of an extracted apple juice was isolated, decolorized and degraded with purified pectin esterase (EC 3.1.1.11) and endo-polygalacturonase (EC 3.2.1.15). Separation of the resulting polysaccharides by anion-exchange-chromatography yielded two neutral and one acidic fractions. Enzymic hydrolysis with purified arabinofuranosidase, endo-α-1,5-arabanase and partial acid hydrolysis in combination with methylation analysis revealed linear α- l-1,5-arabans, highly branched type II-arabinogalactans and rhamnogalacturonans with a high content of neutral sugars, which could not be further degraded by purified pectinases. The isolated polymers are involved in clarification and stabilization problems of apple juice or concentrate.