Why its sweet when we drink water after eating goose berry

when we drink water after eating gooseberry we can get a sweet taste...
why?.whats the chemistry behind it
Vitamin C is present in goose berry.It oxidises quickly ...but tanin is also present in goose berry which prevents this oxidation.....when you drink water a reaction takes place....tanin reacts with water to form gallic acid,ellagic acid,glucose etc........this glucose is responsibile for the sweet taste!!!!!!!