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Purple sweet potato

January 15, 2021
Health benefits of purple sweet potato

If you’ve ever seen purple sweet potato on the inside, you’ve probably wondered where that vibrant color comes from, or if this tuber can be eaten the same way we eat regular sweet potatoes. In this article we not only answer these questions, but we also explain its properties , healthy benefits and forms of consumption , among other information of interest.

What is purple sweet potato?

The purple sweet potato ( Ipomoea batatas Lam ) is a type of sweet potato whose flesh has a very distinctive purplish color. Some claim that the origin of this tuber is located in Central America, specifically in Mexico, while others assure that it is native to Colombia, in South America. The truth is that today, the purple sweet potato has spread throughout the world, including regions of Africa and Asia. Its production has gained strength in several African countries, China and Japan, with the Japanese island of Okinawa being the producer of the striking varieties with white skin and pale mottled flesh. It is also widely grown in Hawaii, from where it is exported to the continental United States (a popular product with Asian and Latino communities).

There is no doubt that the color is one of the main characteristics of the purple sweet potato, a trait that is due to the high content of anthocyanins found in this root1 . Anthocyanins are the same compounds that provide pigment to blackberries, blueberries,purple carrots, among other fruits and vegetables.

Nutritional properties

Like all sweet potatoes, purple sweet potatoes are rich in carbohydrates, vitamins (C, B6, A), minerals (potassium), dietary fiber, and antioxidant compounds. Specifically, anthocyanins, unique to purple fruits and vegetables, are not only responsible for their striking color, but also for some important health benefits.

To see more details about the nutritional profile of this tuber, see Nutritional Properties of Sweet Potato

Health benefits of purple sweet potato

Researchers have found that the anthocyanins present in the root and the derivatives of caffeoylquinic acid present in the leaves of the plant, are the two most important active components of the purple sweet potato.

Anthocyanins have been shown to help:

  • Reduce uric acid levels in the blood and the risk of developing gout by inhibiting an enzyme called xanthine oxidase, which produces uric acid from purines in the body.2  In addition, it helps reduce the reabsorption of uric acid in the kidneys from the urine3.
  • Control blood sugar levels , increasing insulin sensitivity, decreasing inflammatory molecules and increasing the production of glucose transporters in muscle tissue4.
  • Protect liver health by reducing inflammation5  and stimulate the production of antioxidant enzymes to combat the action of free radicals6.

Derivatives of caffeoylquinic acid in sweet potatoes help to:

  • Eliminate excess sugar in the blood by increasing the secretion of GLP-1, a substance that stimulates the secretion of insulin, while reducing the production of glucose in the liver7.
  • Reduce oxidative stress and pro-inflammatory cytokine secretion after exercise8.

In general, it is said that thanks to these properties and the presence of other bio-active compounds (alkaloids, triterpenes, coumarins, carotenes), the purple sweet potato can be beneficial for :

  • Control hypertension 9
  • Treat gout disease
  • Reduce oxidative stress, inflammation, and prevent the development of chronic conditions, such as cancer and heart disease
  • Improve liver function
  • Control diabetes
  • Stop premature aging

In addition to this, the purple sweet potato also serves to:

  • Lose weight . In addition to its lowering effect on blood sugar and insulin levels ( spikes in glucose and insulin lead to weight gain ), sweet potatoes are rich in fiber. Dietary fiber provides a greater feeling of satiety, prevents us from snacking between meals, overeating, and also favors the proper functioning of the digestive system.10  Including this type of food in the diet, on a regular basis, is a basic step when you want to lose weight and maintain a healthy lifestyle.
  • Fight infections. In one study, purple sweet potato extract was found to have antibacterial activity against some of the more common pathogens, eg E. coli, Salmonella, Proteus, and Vibrio parahaemolyticus.11

Fun fact: The purple sweet potato is a frequent food in the diet of the inhabitants of Okinawa, a region known worldwide for the longevity and good health of its people.

How to consume purple sweet potato

The purple sweet potato can be consumed in the same way that we usually do with the common sweet potato or the potato ; This can be boiled , steamed or baked . Many people use to combine the purple sweet potato, the orange sweet potato and the potato in the same recipe, so that the end result is a colorful, delicious and very healthy dish. Likewise, it can be eaten in the form of puree, chips and sweets.

Being a tuberous root rich in starches, its pulp is used in some regions to make purple sweet potato flour . This flour is then consumed in bread rolls and traditional drinks.

On the other hand, purple sweet potato extract is used industrially to add color in different recipes, for example sauces, dressings, desserts, ice cream, etc.

Although it is not the most common use, the vines and young leaves of the plant are also edible; they can be cooked / sautéed like spinach or any other vegetable.

What does this type of sweet potato taste like?

The purple sweet potato is sweet , tasty , some even say it tastes similar to wine, but its flavor is thicker and drier than that of the common sweet potato.

Traditional Hawaiian Purple Sweet Potato, Coconut Milk and Garlic Puree

In the original recipe 12 Okinawan purple sweet potato is commonly used, but feel free to substitute any variety of this sweet potato. The following ingredients will be needed:

  • 3-4 potatoes address
  • 4 garlic cloves finely minced
  • 1/3 cup coconut milk
  • 1/3 teaspoon sea salt, to taste
  • Pinch of freshly ground black pepper, to taste.

Instructions:

  1. Peel the sweet potatoes and boil them in water until they are completely soft inside. They may take longer to cook than regular sweet potatoes (about 45 minutes to boil and 90 minutes – 2 hours to bake at 350 F).
  2. Drain the cooking water, add the coconut milk and begin to grind the pulp to a puree consistency. If necessary, add more coconut milk to achieve the desired texture.
  3. Now add the garlic, sea salt and a touch of black pepper; mix very well so that all the flavors are integrated and serve immediately.

Contraindications and side effects

So far there are no known significant side effects of purple sweet potato. There are insufficient evaluations to establish the safety of long-term anthocyanin use, nor have any adverse drug interactions been documented.

Taking into account that it is a type of sweet potato, it is advisable to take into account the main contraindications of this tuber, especially if it is consumed on a regular basis. For example, excessive consumption of purple sweet potato could be equally contraindicated for:

  • People with kidney disease 13
  • People with a known allergy to sweet potato

See more details in: Contraindications of Sweet Potato

Does purple sweet potato make you fat?

Being a starch-rich tuber, relatively high in carbohydrates and calories (a 100 gram serving can provide about 100 calories), excessive consumption of purple sweet potato can lead to weight gain , in the same way as common sweet potato. However, when eaten in moderation as part of a balanced diet and active lifestyle, purple sweet potatoes are not only non-fattening, but can support weight loss.

How to select and store the purple sweet potato?

When buying purple sweet potatoes, select firm tubers that do not show cuts, spots, or dents on their skin. The best sweet potato is one with a medium size, tapered ends, and a rounded middle.

To store them, proceed in the same way as with sweet potatoes or potatoes; place them in a basket, in a cool, dry place . Their shelf life is typically shorter than other varieties, so consider using them within 1-2 weeks at most.

Are purple yams and purple yams the same?

No, they are definitely not the same. Although the purple color of their meat can cause confusion, these tubers are different species. The purple sweet potato is a climbing plant that belongs to the Convolvulaceae family, like the rest of the sweet potatoes. Meanwhile, purple yam, also known as ube, is a species in the Dioscorea family, together with the common yam , the wild yam and Chinese yam .

References:

  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1082894/
  2. https://www.ncbi.nlm.nih.gov/pubmed/26201407
  3. https://www.jci.org/articles/view/42344/figure/4
  4. https://www.ncbi.nlm.nih.gov/pubmed/24133614
  5. https://www.ncbi.nlm.nih.gov/pubmed/20934476
  6. https://www.ncbi.nlm.nih.gov/pubmed/21640154
  7. https://www.ncbi.nlm.nih.gov/pubmed/25066255
  8. https://www.ncbi.nlm.nih.gov/pubmed/20864555
  9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4965517/
  10. https://www.ncbi.nlm.nih.gov/pubmed/24629984
  11. https://doi.org/10.1016/j.indcrop.2012.02.042
  12. https://www.thespruceeats.com/okinawa-sweet-potatoes-recipe-3377372
  13. https://www.uptodate.com/contents/overview-of-the-management-of-chronic-kidney-disease-in-adults

My name is Louise Hammond, and I am the creator of this website, a place to find information about tubers, bulbs and medicinal roots. In Dreamsship.com I show the properties, benefits, characteristics, photos and images, ways of growing and how to make delicious meals from starchy vegetables.