Purple Sweet Potatoes: A Japanese Superfood

by Jillian Giandurco

Purple Sweet Potatoes: A Japanese Superfood

Purple sweet potatoes are a popular ingredient in many dishes in Japan. Rich with many nutritional benefits, Bokksu will explain how this delicious vegetable came to be and where you can find them!

What is a Purple Sweet Potato?

Before you can start incorporating purple sweet potatoes into your meals, you need to know more about them first. As the name implies, purple sweet potatoes are brightly colored root vegetables that are available in two varieties: Okinawa and Stokes. Okinawan sweet potatoes have a white exterior and a purple interior, while Stokes’ are purple on the inside and the outside. These eye-catching vegetables get their color from anthocyanin pigments, which are the same pigments that give cherries, strawberries, and purple yams their colors. As for what they taste like, purple sweet potatoes typically have a mildly sweet, wine-like flavor to them.

 A basket of purple and white sweet potatoes.

Despite their popularity in Asian countries like Japan, purple sweet potatoes actually have origins in Colombia and Central America. The sweet potatoes were then brought to Asia after Christopher Columbus’s exploration of the Americas, and the white variation of the vegetable was eventually created in Okinawa, Japan. Then, In 1978, a family known as the Decoite family began harvesting the vegetable in Moloka’i, Hawaii, which is where the purple sweet potatoes are mainly exported from today.

Nutritional Benefits of Purple Sweet Potato

Don’t let their sweet coloring fool you – purple sweet potatoes are packed with nutritional benefits, and it’s all thanks to the anthocyanins. If you didn’t know, anthocyanins are similar to antioxidants in that they help reduce inflammation and boost immune support. To give you a better idea of their nutritional value, purple sweet potatoes have about three times more anthocyanins than blueberries.

Three purple sweet potatoes.

Plus, purple sweet potatoes are packed with Vitamin C and potassium, too. And if you’re looking for even more health benefits, you can also eat the skin of your purple sweet potatoes to help increase your fiber intake.

How to Cook a Purple Sweet Potato

The only thing better than a baked sweet potato is a baked purple sweet potato. Don’t believe me? Try this recipe out for yourself: 

  • Preheat the oven to 400 degrees
  • Rub the purple sweet potato(es) in olive oil and salt, then place on a baking sheet.
  • When ready, place sweet potato(es) in the oven for 60 minutes.
  • Test the consistency with a fork; if it needs more time, place it back in the oven and check on it frequently for the next 30 minutes or until baked.

You can also boil your sweet potatoes on the stove for 30-40 minutes, or roast them in the oven or in an air fryer.

Purple Sweet Potatoes vs. Ube

People often confuse purple sweet potatoes for purple yams, or ube, and though the two vegetables have a similar look, they are not the same due to the fact that yams are grown on trees, while sweet potatoes are a root vegetable. Still, ube can be easily substituted for purple sweet potatoes in most recipes, and vice versa – the purple veggies not only have the same sweet yet earthy taste and texture, but they share a lot of the same nutritional benefits as well.

Tips for Purple Sweet Potatoes

Just like all sweet potatoes, you shouldn’t store your purple sweet potatoes in an extra-cold place like the refrigerator. Instead, try storing your purple delights in a cool, well-ventilated container like a basket, or take your storage to the next level and let them sit in a basement or a root cellar. Keep in mind, though, that purple sweet potatoes have a shorter shelf life than regular sweet potatoes, and that they should be used within a week.

Though they might not be as easily accessible as regular sweet potatoes, purple sweet potatoes can be found at most major health food retailers, like Whole Foods and Sprouts.