When choosing watermelon, consider its source, the condition of its rind, and how it has been stored. The season, stem, and appearance do not reliably indicate nitrate levels; reliable measurement requires laboratory analysis. Putting a slice in water and watching its color is not a safety test.
What if symptoms develop? Nausea or diarrhea after eating watermelon does not by itself establish nitrate poisoning. Seek medical care for frequent vomiting, severe or persistent diarrhea, or signs of dehydration. Call 112 immediately for shortness of breath or bluish lips or skin. The time symptoms begin varies with the cause.
How should you choose watermelon? Avoid cracked or rotten fruit. If buying precut watermelon, choose refrigerated products; avoid slices left exposed without refrigeration. Buying from a reputable seller makes it easier to assess handling and storage.
How should it be stored? Before cutting, wash the rind under running water, scrub with a clean brush, and dry with a clean cloth. Use a clean knife and board. Store cut watermelon in a covered container at 4 °C / 40 °F or below; refrigerate within 2 hours of cutting, or within 1 hour if the temperature is above 32 °C / 90 °F. Discard it if it shows spoilage; a normal appearance alone does not establish safety.
This content is for informational purposes only and is not medical advice. Consult a physician before making decisions about your health.