April 22, 2010
I mentioned recently that I'd picked up a Borner V-Slicer mandoline at Goodwill for $2.99 to add to my growing collection of thrifted kitchenware, and used it to cut carrots for sushi. I actually enjoy cutting vegetables by hand, so I cut the rest of the sushi veggies with my santoku, putting the V- Slicer away for another day. That day arrived sooner than I thought it would, with a terrible urge to cut potatoes into shoestrings and fry them in a pan.
We always seem to buy potatoes and forget about them, so when I went for the bag, the poor taters were covered with big sprouting eyes. So are these things poisonous or not, and are the potatoes safe to eat if you cut off the sprouts? What about green spots? After much research, I found advice ranging from, "not poisonous at all" to "discard potatoes that are turning green or sprouting." Even Rachel Ray weighed in on the subject with a video assuring everyone that poisonous potato eyes and green spots are an urban legend. After reading everything I could find, I've come to the conclusion that neither sprouting potato eyes or green-tinged potatoes are good to eat. The green color, while not in itself toxic, is an indicator that the potato has increased its production of solanine and should be discarded. Special care should be taken if children will be eating the potatoes as they are more susceptible to toxins.
Wikipedia said this: "Potatoes contain toxic compounds known as glycoalkaloids, of which the most prevalent are solanine and chaconine. Solanine is also found in other plants in the family solanaceae, which includes such plants as the deadly nightshade (Atropa belladonna), henbane (Hyoscyamus niger) and tobacco (Nicotiana) as well as the potato, eggplant and tomato. This poison affects the nervous system causing weakness and confusion. These compounds, which protect the plant from its predators, are generally concentrated in its leaves, stems, sprouts, and fruits. Exposure to light, physical damage, and age increase glycoalkaloid content within the tuber; the highest concentrations occur just underneath the skin. Cooking at high temperatures (over 170 °C or 340 °F) partly destroys these."
"Glycoalkaloids may cause headaches, diarrhea, cramps and in severe cases coma and death; however, poisoning from potatoes occurs very rarely. Light exposure causes greening from chlorophyll synthesis, thus giving a visual clue as to areas of the tuber that may have become more toxic; however, this does not provide a definitive guide, as greening and glycoalkaloid accumulation can occur independently of each other. The U.S. National Toxicology Program suggests that the average American consumes at most 12.5 mg/day of solanine from potatoes (the toxic dose is actually several times this, depending on body weight). Dr. Douglas L. Holt, the State Extension Specialist for Food Safety at the University of Missouri, notes that no reported cases of potato-source solanine poisoning have occurred in the U.S. in the last 50 years, and most cases involved eating green potatoes or drinking potato-leaf tea."
I also found this: "Many plants contain small amounts of naturally occurring toxic chemicals. For example, two commonly eaten foods, the potato and the tomato, come from the nightshade family. The nightshade family is known to contain toxic compounds called alkaloids. The alkaloid in the potato is solanine. In the United States, healthy potatoes contain 1 to 5 milligrams of solanine per small potato. Under current FDA regulations, 20 milligrams of solanine per 100 grams (a small potato) can render it unfit to eat. Solanine is produced as the potato gets old or is exposed to light. So consumers should avoid potatoes that are old, sunburned (green under the skin) or spongy. Under these conditions, the solanine levels can increase sevenfold or more. Do not eat the potato eyes because they contain a high concentration of solanine. Toxic amounts of solanine can seriously affect the nervous system and have caused death." Source: Angela Fraser, Ph.D., Assistant Professor, Food Safety Specialist, North Carolina Cooperative Extension Service, North Carolina State University.
And I found similar advice on Snopes, my favorite myth-buster site, to discard potatoes with green eyes, sprouts or greenish skin.
But on Chow.com, an article by Roxanne Webber states what I always believed, that if you cut off the offending onion sprout or green part, you can eat the rest of the potato. "Potato sprouts are considered toxic due to their potentially high concentration of glycoalkaloids," says Dr. Nora Olsen, an associate extension professor and potato specialist at the University of Idaho.
“Potato alkaloids exert their toxic effects on the nervous system by interfering with the body’s ability to regulate acetylcholine, a chemical responsible for conducting nerve impulses,” notes UC Davis vegetable specialist Marita Cantwell in the Perishables Handling Newsletter, Issue No. 87. She explains that the main types of glycoalkaloids found in potato sprouts are a-solanine and a-chaconine. “[S]ymptoms of solanine toxicity include headache, nausea, fatigue, vomiting, abdominal pain, and diarrhea,” she writes. Cooking is not believed to reduce levels of the compounds, but you can cut the sprouts off and still safely eat the potato."
It matters whether the potatoes were stored in the light. “Sprouts exposed to light can have two to four times more glycoalkaloids than nonexposed sprouts,” Olsen explains.
As with the sprouts, Olsen explains, you can cut the green part off and eat the rest of the potato."
I cooked my elderly potatoes before reading any of the articles, and now I'm wondering if that was such a good idea. But, there doesn't seem to be absolute agreement on whether it's safe to eat potatoes after removing sprouts and green areas. My potatoes had sprouts, but not green skin or flesh, and they had been stored away from light. I carefully removed all traces of the sprouts, and put the potatoes through the small julienne attachment of the slicer. I also shredded half a large onion with the mandoline. If I were still at our house in Wisconsin and had access to my big old cast iron pan, I probably would have used that to fry the potatoes, but I ended up cooking my potatoes in the wok, which has become my all-purpose pan.
The wok was heated, and a couple of tablespoons of canola oil were added and swirled around to coat the cooking surface. Kalonji (black onion seeds) were sprinkled on the wok and the potato-onion mix was arranged in a thin layer on the bottom and sides of the wok. The potatoes were sprinkled with ground cumin and turmeric and left to cook. When the bottom was brown, the potatoes were flipped over for the second side to cook. When the potatoes were tender but crisp, they were finished with fresh ground pepper and a mild hickory-smoked salt.
I recommend making this with fresh, firm, sprout-free, not-green potatoes! I'm composting the rest of my bag because they're old and soft as well as sprouted, and after reading all this information, I've decided to be more cautious with my spuds. Do you use potatoes that have sprouted? Turned green?
Now that we're in Seattle, headquarters of REI, squandering our REI dividend is more fun than ever. It's true I have to check my ego at the door when entering REI alongside the young, hip and fabulously fit crowd, but hey, I've been a member since memberships cost $5. I'm entitled. My husband wanted a new jacket so we spent a LOT of time in the men's department picking one out. It was a lot less expensive than we thought it would be, plus we had a 20% off coupon for each of us, so we had a bunch of dividend dollars left. We headed to the shoe department to look around because I'm always interested in seeking out vegan shoes. I immediately found two pairs of really cute vegan shoes to try. I have to mention that every woman in the shoe department — and there were a lot — was trying on hiking boots, except me. I was trying on CUTE SHOES. Even the sales clerk said, "Hmmm. These are awfully CUTE SHOES for REI." I looked her straight in the eye, and told her all my other shoes were hiking boots, and I needed something different.
This is not far from the truth, but I had to ignore the serious-hiking-boot-action around me to get the CUTE shoes on my feet. I liked them both, and unable to make a choice, I bought both pairs thinking I'd try them at home, and then decide. What should I do??? They are both comfortable. (And yes, I already do have hiking boots.)
There is some confusion about whether or not the Jambu "Pilot" shoes are vegan so I called Jambu to see what's what. The woman I spoke to said three of the four Pilot colors are vegan; black, raspberry and pistachio are vegan but the brown color is leather. This is because the designer couldn't find an acceptable brown vegan material. The box doesn't say "vegan" but the shoes definitely are, according to Jambu customer service. Various Web sites are listing the shoes as nubuck but Jambu told me this isn't the case. That's all I know.