ENZYMATIC BROWNING IN APPLE PULPS

Enzymatic browning in Golden Delicious apple pulp was studied as relat ed to degree of ripeness and temperature (3.5-31 degrees C). Green app le pulp showed the highest rate of browning. This was attributable to differences in ascorbic acid (AA) content and polyphenoloxidase activi ty in young fruits. The rate of browning determined by CIE L measurem ents followed complex temperature dependent kinetics, represented by a multiple linear effects with log time. Equal changes in L parameter yielded straight lines in a log temperature vs log time plot. Inhibiti on with AA caused an initial slow rate of browning and a well defined break point associated with exhaustion of antioxidant properties of th e AA. The greater the AA concentration the longer the initial period.