Use of highly methoxyl-esterified cross-linked alcohol insoluble substance to remove pectinesterase for the reduction of methanol in sweet orange wine

Commercial pectic enzymes (CPE) are used in the winemaking process to improvetheextraction of aromatic substancesandcolor and for the clarification of juices. These enzymes containpectinesterase(PE), which reacts with pectin in the process and catalyzesthe de-esterification ofpectin by the removal of the C-6 methoxygroupsof D-galacturonic acid to release methanol.In this study, cross-linked alcohol insoluble substance (CL-AIS) columns derived from pea pod 50% and 80% degree of esterification (DE) pectin were used to separate PE from other pectinases.Results showed that by using the 80 DE column, PE (PE: 100 unit/mg; polygalacturonase (PG): 6.5 unit/mg; pectinlyase (PL): 82.4 unit/mg; purification fold: 4.8; recovery: 68%) is effectively separated from PL (PL: 445 unit/mg; PG: 8.3 unit/mg; purification fold: 6.7; recovery: 84.3%).Theenzymes were subsequently used to make orange wine to evaluate the effect of different enzymatic treatments on the release of methanol. Lower methanol concentrations throughout fermentation were observed in the enzymatic treatment without PE.