Watermelon

Peak Season: May to August

Perfect Pick: Dense, symmetrical melons that are free of cuts and sunken areas. The rind should appear dull, not shiny, with a rounded, creamy-yellow underside that shows where ground ripening took place. A slap should produce a hollow thump.

Handle with Care: Store whole in the fridge for up to 1 week. The cold prevents the flesh from drying out and turning fibrous.

The Payoff: Citrulline, an amino acid that’s converted to arginine, which relaxes blood vessels, thus improving blood flow.