By SUSAN CALLAHAN, Associate Editor and Featured Columnist
Recently, a friend served up a dinner of yuca and baked chicken which I was so delicious that I found myself asking "Why don't I cook more yuca?" Yuca tastes a lot like sweet potatoes to me and it can fill the same role as potatoes in any meal. But while sweet potatoes have taken off in the US market as a great, lower carb alternative to white potatoes, yuca ...not so much.
Yuca root is a traditional starch staple in Caribbean and African cooking, especially in Nigeria and Mozambique.
Yuca, technically cassava, is a tuber (root) of a plant grown in most of the tropical regions of the world. After rice and corn (maize), yuca is the third most popular starch consumed in Third World countries.
Yuca Can Contain High Levels of Cyanide
Yuca varieties are either bitter or sweet. Many people believe, wrongly, that only the bitter varieties can contain large amounts of cyanide. Actually, both varieties contain cyanide compounds and you should not rely on bitterness as a gauge for whether the yuca is toxic, according to the Food and Agricultural Organization of the United Nations (FAO).
Yuca's toxicity comes from a compound called "linamarin". Linamarin is usually stable and harmless and remains so even when you boil it. Usually, you eat it, it stays intact, and passes out your stool.
But, and here's the rub, sometimes once linamarin is eaten and reaches your gut, the linamarin compound can become unstable. When it does, linamarin can release cyanide into your blood stream.
How much cyanide? The cyanide content of yuca ranges from 15 and 400 mg HCN/kg. Is this level toxic? Some scientists put the level of toxicity at 20 mg while others put it at 50 to 60 mg per day.
Symptoms of yuca poisoning include vomiting or thyroid or goiter problems, caused because the cyanide in yuca interferes with the body's ability to absorb iodine.
Eating protein mitigates the interference with idodine. This explains why Amazon tribes in Brazil, who may eat a whole kilogram (1000 grams) of yuca daily do not experience goiter/thyroid problems. These tribes people also eat lots of protein from fish with the yuca.
You can lower the yuca content to non-toxic levels by leaching them first in cold water, the FAO advises. After leaching the yuca in cold water, boiling them for 30 minutes reduces the initial cyanide content by 92%.
Do Potatoes Contain Cyanide?
Potatoes do not typically contain detectable levels of cyanide but that doesn't mean that they don't contain toxins.
When potatoes show "greening" or have sprouts, they may contain levels of toxins called " solanine and chaconine", according to the Canadian Food Inspection Agency.
These two toxins are glycoalkaloids which produce a bitter or burning taste in your mouth. Most of the toxins are found in the peel or just below the potato peel.
Unfortunately, once a potato has started to green or sprout, boiling, soaking or even frying won't get the toxins out.
Does Yuca Have More Carbohydrates Than Potatoes?
The short answer is "yes". Yuca contains 78 grams of carbohydrates per cup. White potatoes contain an average of 10 grams per cup. Sweet potatoes contain an average of 16 grams of carbohydrates per cup.
So, yuca contains 5 times more carbs than sweet potatoes and almost 8 times the carbs of white potatoes.
Is Yuca a Low Glycemic Index Food?
Yuca has a glycemic index value of 46. Sweet potatoes have a glycemic index value of 50. And white potatoes (whether baked, grilled or fried) have a glycemic index value of 95. So, yes, yuca certainly has a lower glycemic index value than potatoes.
Foods having a glycemic index value over 55 are generally considered "high glycemic" index foods. Corn syrup has a glycemic index value of 115 for example and white sandwich bread has a glycemic index value of 85.