You can add any scanned item to your Favorites by simply tapping the favorite (star) icon on the upper right:

Once added you can remove items from your Favorites by either tapping the star icon again to unfavorite the item or by following these steps:

  1. Navigate to your Favorites tab under Add > Food > Favorites
  2. Tap to select the item you want to remove from your list
  3. Then simply tap the filled in star icon again to unfavorite