Store the fruit slices in a ziploc bag.
After soaking my fruit slices, I drain off the liquid and store them in a ziploc bag in the fridge. Squeeze as much air out of the bag as possible before sealing it. Amazing how long the apples stay fresh and and crispy this way. Their storage life can vary depending on the type and freshness of the apples. If you're using apples that are in season and fairly freshly picked, they will stay fresh longer than those that have been picked and stored for a long time. I've had them keep for up to a week.