Rw. Chen et al., PECTINESTERASE AND PECTIN COMPLEXES INHIBIT ION-EXCHANGE MEMBRANE SEPARATION, Journal of agricultural and food chemistry, 46(5), 1998, pp. 1777-1782
Ion exchange membrane disks (FMC Co., Pine Brook, NJ) equilibrated at
pH 5.0, 6.0, 7.2, and 8.0 were tested for separation of pectinesterase
(PE) extracted from Marsh grapefruit (MGF) pulp. Anionic exchange dis
ks (QUAT, DEAE, and PEI) bound less PE and protein than cationic excha
nge disks (SP and CM). Less than 20% of PE was bound to SP membrane at
pH 6.0, 7.2, and 8.0. Law PE binding ability in the ion-exchange syst
em may be attributed to the presence of PE-pectin complexes, which act
as a competitor with the inorganic ions of the membranes. Water washi
ng the pulp prior to PE extraction lowered the pectin content by 86%,
but did not substantially improve PE binding to SP membrane.