A suggestion for @André Toulon who can certainly disallow it...
As long as your can show an actual picture of the item you have in your cabinet or refrigeration, providing a nutritional value from other sources, including screenshots, could be acceptable. It's worth noting that most produce and even most fruit has naturally occurring salts, so this may still require significant amount of creativity to work.
The point of the competition isn't what labels you have in your cabinet, it's to show the actual item.