Continuous production of pectic oligosaccharides in an enzyme membrane reactor

The use of high methylated (60% to 66% methylation) and low methylated (8% methylation) pectin for the continuous production of pectic-oligosaccharide s in an ultrafiltration dead-end membrane reactor was investigated. Substra te concentration (1% to 5% w/v), enzyme concentration (90 to 2700 U l(-1)), and residence time (40 to 120 min) were the factors studied. Response surf ace methodology was used to model the processes. Two responses were determi ned: conversion of pectin(s) into product, and product dextrose equivalent values (DE). Mathematical models were fitted for each response. Conversions to product ranged from 67% to 99.7%. Product DE values increased with incr easing residence time from 27 to 70. The average molecular-weight distribut ion of the products obtained was 3.5 kDa when high methylated pectin was us ed as substrate and 3.8 kDa for low methylated pectin.