1. Yellow (inner) skin is a sign of high concentration of nitrates
Nitrogen is an important element in plant growth and development. Nevertheless, watermelon growers tend to exceed the norm, with the goal of gaining 25 pounds more within just 3 weeks. So the buyer ends up being poisoned. So when you wait for the fruit in question you should not have any yellow skin or white stripes in the interior.
See if the watermelon has holes
Some people believe that these holes are nothing but traces of insects and not nitrate, but you, for your own good, stay away.
Even if in the foreground the watermelon looks good, with the passage of hours a significant part will be lost due to the presence of the hole.
3. Do not eat watermelon that has a large but hollow heart
If the heart is empty or, as we say, "dropped" it indicates that the fruit is too mature or contains growth hormones. If a very mature watermelon can be just a bit bitter and so, a watermelon that has hormones can cause poisoning. That is why not consume fruit if it is in such a state.
4. Insert a part of the heart into the water just before you consume the fruit
With a small trolley you can easily check the percentage of nitrate in watermelons. Take a container and fill it with water at room temperature. Leave it for a while, and if the water has a light pink color, flush the watermelon without thinking twice.
