Okinawan Purple Sweet Potato - just came across these, interesting ...
OR even better the USA version: Stokes Purple Sweet Potato:
The Stokes Purple sweet potato plant is in the same family as the morning glory. It produces a large sweet tasting tuberous root classified as a root vegetable. This potato has a purple skin as well as purple flesh which maintains its rich color when cooked. Years of development have produced a plant that yields high quality purple sweet potatoes that are unusually healthy and nutritious.
Since the Stokes Purple is locally grown in the USA, it is NOT irradiated before it reaches the consumer. Other varieties of purple sweet potatoes that are imported from overseas must be irradiated when they enter the USA. Also, Stokes Purples have not been genetically modified in any way and are classified as Non-GMO sweet potatoes.
Purple sweet potatoes contain antioxidants that help to prevent diseases, such as cardiovascular disease and cancer. They boost immunity, are anti-inflammatory, and keep bones and skin healthy. The most powerful antioxidants are phytochemicals.
Purple sweet potatoes obtain their rich purple color from the phytochemical, anthocyanin.
Anthocyanin content is retained after cooking or freezing Stokes Purples. (Steed, 2008)
Anthocyanin content in the Stokes Purple is 4 times greater than in Okinawan sweet potatoes.(Truong, 2009)
Moderate consumption of anthocyanin products has been shown in epidemiological studies to reduce cardiovascular disease and improve visual functions. (Hou,2003)
Purple sweet potatoes are high in anthocyanins and show strong radical scavenging activity thus reducing your risk of developing chronic diseases. (Kano, 2005)
Anthocyanins in purple sweet potatoes exhibited memory enhancing effects, which may be associated with its antioxidant properties. (Cho, 2003)
Stokes Purples were found to have nutraceutical components in competitive levels with other food commodities known to be good sources of antioxidants. (Steed, 2008)
Purple sweet potatoes are also diabetic friendly. The Glycemic index is lower in sweet potatoes than in white potatoes. The carbohydrate in foods with a low Glycemic index breaks down slowly, releasing glucose gradually into the blood stream.
The best source of phytochemicals is in whole foods and NOT in expensive dietary supplements. (Liu, 2004)
Purple sweet potatoes rank high in nutritional value along with other purple foods.
Purple sweet potatoes are a high source of:
Antioxidants from anthocyanins and polyphenolic compounds
They are also a good source of:
Purple sweet potatoes are also very low in: Fat, Sodium
People in Japan have used the Okinawan sweet potato to treat diabetes due to its low ranking on the glycemic index scale, used to measure how fast a food is likely to raise your blood sugar. Its beta carotene, or vitamin A, can help improve your immune system, preserve eyesight and fight infections. The antioxidants the potato contains have been linked to a reduction in your risk factor for cardiovascular disease and cancer. The Okinawan sweet potato has 150 percent more antioxidants than blueberries.
They are white skinned with a deep, brilliant purple interior that becomes velvety smooth and incredibly sweet when baked. Even better, the purple pigment is due to the vast numbers of anthocyanins – the very same beneficial antioxidant pigments that provide blueberries their brilliant color and health benefits. According to this entirely unbiased source, Okinawan sweet potatoes contain 150% more anthocyanins than the same amount of blueberries. That sounds reasonable, and a good general rule is the purpler the potato (or bluer the berry), the greater the anthocyanin content.
Several studies show potential benefits to purple sweet potato anthocyanins: suppression of mouse brain inflammation; alleviation of brain aging; reduction in cognitive deficits, inflammation, and oxidative damage in aging mouse brains; potential suppression of neurodegenerative cell death, as in Alzheimer’s; protection against acetaminophen-induced liver damage in mice. In human males with borderline hepatitis, a beverage infused with purple sweet potato anthocyanins “significantly decreased the serum levels of hepatic biomarkers”. Plus, the long-lived, fairly healthy Okinawans have traditionally used Okinawan purple sweet potatoes as a staple food. All the evidence seems to support their status as a healthy, delicious tuber.
There’s another variety that looks extremely similar but has a lightly violet interior streaked with white. It’s starchier and far drier than the Okinawans, and it doesn’t taste nearly as good. If you go looking for Okinawan potatoes in Asian supermarkets (which is the only place I’ve been able to find them consistently), inspect them carefully before buying. I once saw an old Chinese woman at one of these places snap the end of each potato off with her fingernail to check the color inside; this method works well, is relatively inconspicuous, and it’s a good way to make sure you’re getting the true Okinawan sweet potato. Just look for the deep purple flesh.