Dynamics of hydrolytic enzymes activity and associated carbohydrates transformation in custard apple fruits as influenced by fruit surface coating and storage conditions

Investigations on dynamics of hydrolytic enzymes viz., amylase and polygalactouranase (PG) and the corresponding conversion of carbohydrates into sugars as influenced by fruit surface coating material and storage under zero energy cool chamber (ZECC) was undertaken. The twin effects of surface coating application with sago (10% concentration) and ZECC storage was noticed on amylolytic activity and corresponding conversion of starch into sugars during the storage. The fruits treated with a solution of sago (10%) and stored under ZECC registered delayed and slow amylase activity and the concomitant degradation of starch and accumulation of sugars. Similarly, the polygalactouranase (PG) activity and the corresponding softening of fruits was also postponed in treated fruits. The peak amylase activity in fruit pulp and polygalactouranase activity in fruit skin was recorded on seventh day of storage in treated fruits. While in untreated fruit, the activity of amylase and polygalactouranase peaked on third day of storage. The amylase activity was found to have correlation with transformation of starch to sugars and PG activity was associated with fruit softening and ripening.