MEMBRANE FOULING AND MOLECULAR-WEIGHT CUTOFF EFFECTS ON THE PARTITIONING OF PECTINESTERASE

The effects of membrane fouling and molecular weight cutoff (MWCO) on the partitioning of pectinesterase (PE) isolated from Marsh grapefruit were evaluated. Statistically higher fouling rates were observed for Marsh grapefruit extracts on 30K and 100K poly(sulfone) UF membranes t han on a similar membrane with a MWCO of 10K. A simple logarithmic exp ression adequately described the fouling phenomena for all three UF me mbranes. The permeability of PE was also determined by using the same membranes and found to decrease 30-60% during processing regardless of the MWCO of the membrane. Permeability was found to decrease in a fas hion similar to permeate flux. A separate logarithmic expression was d eveloped to evaluate the rate of change of permeability on each of the membranes. About 40-50% of the total activity in the permeate of the 30K UF membrane was thermostable PE.