Kiwifruit

Get nearly a day's worth of immune-boosting vitamin C in
every one of these juicy gems.
Choose plump fruits (they're considered berries) without
wrinkles or blemishes. For the most fiber and nutrients, try
eating them unpeeled.
Keep kiwis on the counter until they give slightly to gentle
pressure, and then store in the fridge for a week or two.
-Prevention Magazine, January 2013