About Watermelon Seeds

Watermelon seeds are edible.

A juicy slice of red watermelon is a relief on a hot day. The high water content and crisp flesh provide a cool, nutritious treat. In the United States, people eat mostly the watermelon flesh and occasionally the rind in pickled form, using the seeds for no more than spitting contests. Those seeds, though, are edible.

Horticultural Information

Watermelon (Citrullus lanatus) is related to pumpkins, cucumbers and squash, all a part of the Cucurbitaceae family. Despite the image and use of watermelon as a fruit, it is a vegetable. Watermelons grow well in warm climates, with ideal temperatures in the low 80s F, although they can grow in most parts of the country, notes the University of Illinois Extension. Rows of black seeds run through the interior flesh. Seedless watermelons can still have soft, immature, white seeds.

Seedless Germination

Seedless watermelons still grow from seed. The seedless melons are sterile--obviously, as they have no seeds--so a seeded melon and a genetically related but modified melon are crossed to produce another seeded melon whose seeds will grow into seedless watermelons. The modified parent melon is diploid, meaning it has double the usual number of chromosomes. The child melon is triploid, or it has three times the chromosomes. As Purdue University points out, the sets of chromosomes divide in half first, and then combine with chromosomes from the other parent melon. Three doesn't divide cleanly in half. This renders the seeds from the child melon unable to produce melons with more seeds, because it can't pass along chromosomes.

As Food

Roast or toast dried watermelon seeds for a snack. OChef says some varieties of watermelon in Nigeria produce seeds suitable for soup. Watermelon seeds provide substantial amounts of zinc and iron, but also make for a caloric and fatty snack. They are low in sodium, and they are a source of protein.

Considerations

The black portion of the watermelon seed is actually the husk, covering the nutritious part of the seed. OChef notes that just swallowing the seeds won't provide you with any benefit as the seed will pass through you. You must chew them or somehow get the center out of the husk.

Warning

Ensure that any watermelon seeds you buy to eat are prepared safely, especially when traveling. The Saigon Giai Phong newspaper reported in December 2009 that the Vietnamese government had begun looking into companies that produced watermelon seeds for food, after an investigation in central Vietnam found seeds soaked in rhodamine, a carcinogen. In January 2010, the paper noted that a company in Ho Chi Minh City had used rhodamine and colored the seeds with a prohibited dye.

References

• University of Illinois Extension: Watermelon
• Purdue University: Seed Germination and Health for Triploid (Seedless) Watermelons
• OChef: Nutritional Merits of Watermelon Seeds
• Saigon Giai Phong: National Investigation Launched Into Toxic Watermelon Seeds
• Saigon Giai Phong: Watermelon Seeds Test Positive for Toxins

Resources

• Planet Green: 5 Reuses for Watermelon
• Nutrition Data: Seeds, Watermelon Seed Kernels, Dried