Optimization of enzymatic preparation for passion fruit juice liquefactionby fractionation of fungal enzymes through metal chelate affinity chromatography

Immobilized metal ion affinity chromatography (IMAC) enables the fractionat ion of commercial fungal enzyme preparations. Pectin-lyase showed no affini ty with the chromatographic matrix at pH 7. Endo-glucanase and cellobiohydr olase were both eluted in almost all fractions but predominantly in three f ractions when pH decreased. This suggests that IMAC can discriminate betwee n different forms of cellulase isoenzymes. Polygalacturonase and pectineste rase were released with last fraction, showing their strongest affinity for the matrix. Following an experimental design, IMAC fractions containing se parately pectin-lyase and cellulase have been used to formulate an optimal enzymatic preparation for liquefaction of passion fruit pulp, It has been f ound that for every liter of passion fruit juice, at least 85 units of pect in-lyase, 100 units of cellobiohydrolases and 700 units of endo-glucanases are required for convenient liquefaction after 1 hour of incubation at 30 d egrees C.