Purple Sweet Potato vs Sweet Potato: What’s The Difference?

The traditional sweet potato and the purple sweet potato are two of the most common. Having many similarities between the two, many people wonder about their differences. Let’s answer, what is the difference between sweet potatoes and purple sweet potatoes?

Sweet potatoes have a bronze outer skin with an orange flesh inside. Purple sweet potatoes have a beige outer skin with a purple flesh inside. Sweet potatoes are a little sweeter than purple which have a milder flavor. Purple ones are denser requiring longer cooking times.

Other differences between sweet potatoes and purple sweet potatoes:

  • Purple sweet cost more.
  • Sweet potatoes are easier to find in supermarkets.
  • Purple sweet contain more of the antioxidant anthocyanin.
  • Sweet potatoes contain more beta-carotene than purple sweet potatoes.

This article will compare in complete detail including their nutrients, tastes, costs and whether one can substitute for the other in recipes. In addition, I’ll examine their benefits and if one is easier to store than the other.

As a Certified Health Coach many of my clients ask about sweet potatoes. In addition to coaching clients about them, I’ve purchased, researched and consumed both prior to, during and after writing this article.

Purple sweet potatoes on the left and sweet potatoes on the right
Purple sweet potatoes on the left and sweet potatoes on the right

Purple Sweet Potatoes and Sweet Potatoes: Differences

What Is a Sweet Potato?

Most people may think they are a member of the potato family 1. However, it is not related to the potato plant Solanum tuberosum as their composition of simple sugars and complex starches is pretty different.

Sweet potatoes are root vegetables that have the scientific name Ipomoea batatas and are part of the morning glory family, Convolvulaceae. They are native to Polynesia and the Central and South America region, domesticated more than 5,000 years ago, and grown worldwide today. 

Interestingly, they can come in various varieties, each having different flavors, sizes, shapes, textures, and firmness. You can purchase them all year round, and the most common types in the U.S. are the:

  • Beauregard
  • Jewel
  • Garnet

These three are the most common and usually have orange, rose, or reddish-colored skin.

Are They Yams?

Many people confuse sweet potatoes with yams. A true yam has a bark-like skin with hairs. Its flesh is a light color and is dry and starchy. Many sweet potatoes are marketed as yams. Those have both names on the label but are not yams.

Although they are sometimes mistaken for yams, they are more firm on the inside and have a slightly sweet taste.

What Are Purple Sweet Potatoes?

Like other sweet potatoes, purple sweet potatoes are root vegetables and are members of the Ipomoea genus. 

The purple color is not manufactured but an entirely natural process. It comes from an antioxidant called anthocyanin, which is colored water-soluble pigments that can give plants, fruits, and other vegetables their rich coloring. 

There are two main common variations of purple sweet potato. These include:

Okinawa Purple

  • Okinawa sweet originated in Central and South America but are locally grown in Hawaii. They have white skin with deep purple flesh. Although they have a bluish-purple color, their texture is dry and starchy with a mildly sweet and bitter aftertaste.
Stokes purple sweet potatoes
Stokes purple sweet potatoes

Stokes Purple

  • Stokes from North Carolina originally but is grown commercially in Central California. Stokes purple has a moist and starchy texture and a mildly sweet floral taste. Available year-round, they have purple-tinted skin with a deep purple flesh that intensifies when cooked.

All purples can be easily made and still retain their rich purple color even when cooked.

Nutrition Differences: Purple Sweet vs Orange Sweet

All sweet potatoes have similar vitamin and mineral content making them great allies in supporting your overall health. The following are the amounts and nutrients per one cup:

Nutrient Sweet Potato (1 Cup, raw)
Calories 114
Fat 0.1g
Protein 2.1g
Carbohydrates 26.8g
Fiber 4.0g
Sugar 5.6g
Vitamin A 18,866 IU
Vitamin C 3.2mg
Vitamin B6 0.3mg
Magnesium 33.2mg
Potassium 448mg
Copper 0.2mg
Manganese 0.3mg
Iron 0.8mg
Vitamin E 0.3mg
Calcium 39.9mg

Nutrition source 2 3

They include a high level of:

  • Vitamin A
  • Vitamin C
  • Magnesium
  • Potassium
  • Calcium
  • Fiber

Let’s now talk about a couple of nutrient differences between an orange sweet potato and a purple sweet potato.

Orange Sweet Potato Phytonutrient Profile

Phytonutrients protect plants from germs, fungi, bugs, and other threats and can also help prevent disease and keep your body working correctly.

Sweet potatoes with orange flesh are high in beta-carotene, which gives that yellow, orange, and red coloring to fruits, plants and vegetables. Beta Carotene also helps promote vitamin A in the body as well as promotes eye health.

Purple Sweet Potato Phytonutrient Profile

On the other hand, purple potatoes are richer in anthocyanins. As mentioned earlier, anthocyanins are the pigments that give red, purple, and blue fruits, plants and vegetables their rich coloring and provide anti-inflammatory benefits.

A bunch of different kinds of potatoes including sweet potato and purple sweet potato
Different sweet potatoes and potatoes

Which is Healthier?

When comparing both potatoes, it’s difficult to say if one is healthier than the other. They both provide a wide variety of vitamins, minerals and phytonutrient profile.

For this reason many people ask, which sweet potato is healthier?

Purple sweet potatoes are healthier due to their highest overall level of phenolics, antioxidants and soluble dietary fiber. They provide a higher level of anthocyanin antioxidants than orange or white flesh sweet potatoes.

Find out how purple yams compared in my article here.

Taste and Texture

Due to their different color flesh, one would think they taste different. Let’s examine the different taste and texture of each sweet potato.

Purple sweet potatoes have a rich taste, almost wine-like flavor with a creamy texture. Sweet potatoes are sweeter and moister than the drier purple. Purple are starchier than the orange.

Sweet potatoes hold their sweetness consistently. There’s a subtle starchy undertone with rich sweet flavor. They have a stringy, soft, crumbly texture. For a delicious meal, pick these potatoes sweet in flavor.

Purple sweet have a rich taste with a wine-like flavor. The texture is dry but slightly creamy.

To conduct some original research, I polled readers, clients and members of food groups. I asked them which one do they prefer the taste of.

  • 49% said they preferred orange sweet.
  • 41% said they preferred the taste of purple sweet.
  • 10% said they never tried purple before and couldn’t answer.

Find out how white sweet potatoes compared in my comparison article.

How to juice purple sweet potatoes.

How to Cook and Substitutions

Purple sweet potatoes and sweet potatoes can substitute for each other in recipes for almost any dish. They can both be baked, roasted, mashed or grilled. Purple ones are drier, therefore, they will need longer cooking times than orange ones.

There are a few things you should consider before substituting these vegetables in recipes.

  • Increased cooking times is recommended for purple. This is due to their drier and denser flesh. The longer cooking time will make it moister. They need to be baked for approximately 90 to 120 minutes at 350 degrees.
  • If you’re substituting regular sweet for purple in a recipe, remember to shorten the cooking time.
  • The quantity needed in recipes doesn’t change when substituting one potato for the other.
  • Purple potato may be more difficult to find in traditional supermarkets. Don’t confuse them for an Ube which is actually a yam.
  • It may be harder to find recipes including purple.

If you are making pie, the purple sweet may lack the sweetness needed. Therefore, you may be changing the recipe slightly to make the dish a bit sweeter.

For fries, purple potatoes have the advantage. They are versatile, and you have more control of the resulting flavor because their overall taste is subtle compared to an orange one.

The following video explains how to bake a sweet potato.

Cost of Potatoes

With the rising prices of just about everything lately, the cost of something certainly matters to most people. The price may sway your decision about one to use. Therefore, let’s take a close loom at the prices of each potato.

Purple sweet potatoes cost $2 more per pound than sweet potatoes. The average price for sweet potatoes is $0.99 per pound. The average price for purple sweet potatoes is $2.99 per pound.

To conduct original research, I decided to visit a few local supermarkets and compare the prices of each one.

I first visited the Shoprite supermarket and these are the prices I found:

  • Sweet
    • $0.99 per pound
  • Purple sweet
    • $2.99 per pound

I also checked Walmart and only found the regular:

  • Sweet
    • $0.98 per pound

I then checked a specialty store (Friedas) and found the following prices:

  • Purple sweet
    • $4.00 per pound
A picture of sweet potatoes taken by Kevin Garce in his local supermarket while checking prices
A picture of sweet potatoes taken in my local supermarket while checking prices

Where to Buy and Availability

Sweet potatoes are generally available year-round, but purple sweet potatoes like the Okinawans are usually available between late summer through late spring. In contrast, the Stokes variety is open from September through June.

Depending on where you live, it may be difficult to find purple sweet in the local stores. You’ll have better luck in specialty type markets selling international products. They are easier to find online.

Find out how Russet compared to Yukon Gold Potatoes in my latest article, Yukon Gold Potato vs Russet Potato: What’s The Difference?

How To Store Potatoes

Purple and regular sweet potatoes are both stored in a cool, dry, ventilated container. They should be kept out of the refrigerator in a dark place away from heat. A humid basement or root cellar is the best area.

Keeping them in the refrigerator produces a hard center and an unpleasant taste. They can store for about two weeks in the proper conditions 4.

When looking at either one at the market, always choose large ones which feel firm. If you have a local farm or roadside stand close by, buy them there.

The ones in the supermarket probably have been stored for months, while farm-fresh potatoes may only be a week old.

How long do purple sweet potatoes last? Purple sweet potatoes store bought can last for about two weeks if properly stored. Keeping them in a dark, cool place away from heat will make them last longer. Store them anywhere from 55°F to 60°F and keep them out of the refrigerator.

Can purple sweet potatoes and sweet potatoes be stored together? Purple sweet potatoes and sweet potatoes can be stored together in a cool, dark place at a temperature between 55°F and 60°F. Keep them in a ventilated container like a potato keeper or burlap bag.

Find out if Russet potatoes and Idaho potatoes are the same in my article, Idaho vs Russet Potatoes – Are They The Same? Let’s Compare

sweet potatoes being stored in a climate controlled warehouse
Potatoes stored in a climate controlled warehouse

Health Benefits

Glycemic Index

The glycemic index (GI) measures how various foods can increase or decrease your blood sugar level. When boiled, purple sweet potatoes have a lower GI than regular sweet potatoes.

So if you’re looking to keep your diet low in carbs, you might want to look for other alternatives lower on the glycemic index. Although the carbs in sweet potatoes are complex and raises blood sugar more slowly.

Sweet potatoes have a moderate glycemic index and is considered safe for most people.

If you’re interested about how pumpkin compared for health and nutrition, check out my article here.

Eye Health

There are two nutrients the body converts into vitamin A. Most notably, Beta Carotene, which is easily absorbed by the body. According to scientific studies, vitamin A helps the eyes when it comes to dim light vision and dry eyes 5.

Consuming one regular sweet potato provides 730% of the daily value for vitamin A. Their Anthocyanins have been found in studies to protect eye cells from damage improving overall eye health 6.

The Immune System

According to Harvard University, vitamin A is a great source to stimulate healthy white blood cells 7. These cells have the responsibility of keeping the immune system as healthy as possible to fight viruses and illnesses effectively.

Other nutrients like the antioxidant anthocyanin and vitamin C possess anti-inflammatory properties protecting against disease and illness.

https://www.youtube.com/watch?v=4f7b7_ND9eQ
Lee Health explains the health benefits of sweet potatoes.

Gut Health and Digestion

Both contain soluble and insoluble fiber. Fiber remains in the digestive tract and provides gut related health benefits. Fiber rich diets have been linked to regular bowel movements and a lower risk of colon cancer 8.

Find out how Russet potatoes compared to red potatoes in my article, Red Potatoes vs Russet Potatoes: The Differences.

Blood Pressure

All potato varieties provide a good amount of potassium. It helps the body get rid of excess sodium reducing fluid build-up. These help keep systolic and diastolic blood pressure lower 9.

According to Harvard Health, a number of studies have shown a connection between low potassium levels and high blood pressure 10.

The more potassium, the more sodium your body will lose. Consuming too much sodium or not enough potassium throws off the delicate balance the kidneys need to remove the excess water 11.

A raw sweet potato
A raw sweet potato

Is purple sweet potato high in sugar?

Purple sweet potato is not considered to be high in sugar. They contain 4 mg of sugar per one serving size of 110 grams.

Additional Resources 12 13 14

If you have any questions about this article don’t hesitate to email us. You can find an email on our contact page.

Read Next – More Food vs Food Articles!

Sweet Potato vs. Butternut Squash: A Comparison

Are Sweet Potatoes Healthier Than Regular Potatoes?

Sweet Potato vs. Russet Potato: What’s The Difference?

Red Potatoes vs Yukon Gold Potatoes: What’s The Difference?

Sweet Potato vs Yam Nutrition and Benefit Differences

Article Resources: Foods For Anti-Aging follows strict guidelines to ensure our content is the highest journalistic standard. It's our mission to provide the reader with accurate, honest and unbiased guidance. Our content relies on medical associations, research institutions, government agencies and study resources. Learn more by reading our editorial policy.
  1. Harvard T.H. Chan: Sweet Potatoes[]
  2. NutritionData: Sweet potato, raw[]
  3. USDA: Sweet potato, raw, unprepared[]
  4. North Carolina Sweet Potatoes: How To Store Sweetpotatoes[]
  5. National Center for Biotechnology Information: Nutrients for the aging eye[]
  6. National Center for Biotechnology Information: Review on nutritional composition of orange-fleshed sweet potato and its role in management of vitamin A deficiency[]
  7. Harvard Health: Vitamin A[]
  8. National Center for Biotechnology Information: Mechanisms linking dietary fiber, gut microbiota and colon cancer prevention[]
  9. American Heart Association: How Potassium Can Help Control High Blood Pressure[]
  10. Harvard Health: Potassium lowers blood pressure[]
  11. National Center for Biotechnology Information: The Effect of the Sodium to Potassium Ratio on Hypertension Prevalence: A Propensity Score Matching Approach[]
  12. National Center for Biotechnology Information: Research Advances of Purple Sweet Potato Anthocyanins: Extraction, Identification, Stability, Bioactivity, Application, and Biotransformation[]
  13. National Center for Biotechnology Information: Purple Sweet Potatoes from East Java of Indonesia Revealed the Macronutrient, Anthocyanin Compound and Antidepressant Activity Candidate[]
  14. USDA: Sweet Potatoes & Yams[]

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