Two simple tests with water and iodine can reveal excess nitrates in watermelon. However, these methods are not always 100% accurate. The most reliable way is to use a nitrate tester.
Russian agricultural scientist Nina Myasishcheva explained home testing methods in an interview with Gazeta.ru.
Water test: Drop a piece of watermelon flesh into a glass of water. Cloudy water is normal. If the water turns pink or red, it indicates excess substances. Avoid such watermelon.
Iodine test: Put a drop of iodine on a slice of watermelon. If the iodine turns blue, it may indicate the presence of nitrates.
The scientist notes that the safe nitrate level in watermelon is up to 60 mg per kilogram. Exceeding this limit can cause poisoning. Symptoms include weakness, dizziness, nausea, vomiting, abdominal pain, diarrhea, loss of appetite, and drowsiness.
She also advises to check the appearance: the inside should not be unnaturally bright red; fibers should be white. The cut surface should be velvety and granular. Buy watermelon only from specialized stores, avoid roadside sellers as they absorb harmful substances.
