Preheat oven to 200 degrees F. Line a sheet pan with foil and lightly coat with cooking spray.

Toss the bananas in lemon juice.

Arrange the bananas in a single layer on prepared baking sheet.

Bake for 1 hour; check to see if they are starting to brown. Flip the slices with a spatula, and continue to bake for 45 minutes longer, or until desired crispness.

Cool completely and store in an airtight container.