OLIVE FRUIT GLYCOSIDASES - FACTORS AFFECTING THEIR EXTRACTION

The enzymes alpha- and beta-galactosidase, alpha-mannosidase, and alpha-arabinosidase have been detected in olives during the process of development and ripening. The extraction of enzymes can be achieved at low ionic strength of the medium, which shows that these are not associated with the cell wall. High concentrations of salt strongly inhibited all the enzymes. Consistent determination of activity can be done using the p-nitrophenyl method without appreciable interference below a control absorbance of 0.8 units. However, significant interference was found above this value. The apparent optimum pH for the four enzymes was between 4.3 and 5.3 units. The optimum temperature for a incubation time of 15 min was 50 and 60-degrees-C for alpha- and beta-galactosidase, and 40 and 50-degrees-C for alpha-mannosidase and alpha-arabinosidase. The respective activation energies were estimated. All the enzymes possess a relativelyl high thermal stability, alpha-mannosidase and beta-galactosidase being slightly more stable than alpha-galactosidase and alpha-arabinosidase.