A while ago I read that "all the green parts in tomatoes" actually contain a not so healthy "active ingredient" which would be better not to eat.
What I knew was that we couldn't digest those parts well, but nothing more.
Now I am asking myself if the same can be said for onions, potatoes, paprikas and so on.

What I normally do is:

  • Cut the center (green part) of the tomatoes away
  • Cut the center of the onion away (even if not sprouting)
  • Cut all the little sprout of potatoes away
  • Cut the white parts inside paprikas away

Since I don't feel good about trashing food, I would like to know if I am just being too cautious, or am actually doing fine.

  • By "pepperonis" do you mean bell peppers? To me, pepperoni is a salami used on pizzas. Jun 29, 2015 at 14:10
  • @DavidRicherby this is a distinctly American meaning. In Italian, the main meaning is "pepper", and many European countries have adopted it for other Italian products made with peppers, for example in Germany it is long thin peppers conserved in brine. As an European, I struggle to find a word for "pepper" which Americans will understand: "pepper" itself can be confused with black pepper and sometimes doesn't encompass hot pepper/chili, "bell pepper" excludes the standard long pepper, and so on.
    – rumtscho
    Jun 29, 2015 at 15:15
  • 4
    @rumtscho No, it's the English-language meaning. Sure, it's confusing that Italian and German use the same word to mean something different but, as far as I'm aware, in English, "pepperoni" only means the salami. That's not restricted to American English: I'm British. The vegetables are "peppers". Using the plural means it's very unlikely to be misunderstood as referring to the powder; the unground spice is referred to as "peppercorns". Jun 29, 2015 at 15:40
  • @DavidRicherby OK, I wasn't aware that it is extended to other English speaking countries, as I think it started with Italian-American cuisine. But yes, it's a false friend in many languages. I think in this question, we can assume it to mean a raw vegetable from the Piper genus, and luckily it isn't important for the answers to find out which one.
    – rumtscho
    Jun 29, 2015 at 15:43
  • @rumtscho : I personally like 'capsicum' to talk about peppers, as there's no ambiguity. Unfortunately, most Americans who aren't foodies or familiar with botany might not know what you're taking about. You could always use 'capsicums (peppers)' to clarify, but then it just starts getting fairly long. See cooking.stackexchange.com/q/784/67 ... there's a section of ~5 bullets talking about pepper vs. peppers under the first heading (vegetables).
    – Joe
    Jun 29, 2015 at 16:11

2 Answers 2


Unless you're planning to consume a few kilo of each of them in one sitting, I would say you're being too cautious. Tomato, bell peppers, chilis and potatoes are all part of the nightshades family, and are toxic to some degree. But the poison is in the dose. The amount contained with in the vegetables would mean you'll have to consume an inordinate amount of it for them to take effect.

I cut the sprouts of a potato, I have to peel them anyway. I usually cut away the "crown" of the tomato, mostly because it's tough and I don't want it in the dish. Most of the time, I don't even bother with the white parts of a paprika if I cook them, only in salads for cosmetic purposes I take them out. Onions just get peeled and used. So far, to no ill effect.


As mentioned by Popup, be wary of green potatoes: Small sprouts or eyes on a potato aren't a problem; Cut them away as you find them. But do cut away green areas of a potato. As the article in the link tells, it's not that the green parts are solanine (the toxic), but rather an indication of areas where solanine build up takes place:

"What is the green? Actually it’s chlorophyll. Not bad for you at all. But the chlorophyll indicates that the potato has been exposed to sunlight. And where the potato has been exposed to light is where a natural toxin in the potato (solanine) becomes concentrated at harmful levels"

No need to discard the entire potato, just get rid of the offensive parts, and when it makes sesnse, i.e.: If you need a microscope to spot it, or if it's the size a pins' head, so to speak, don't worry about it.

  • Apparently tomatoes contain solanine too: en.wikipedia.org/wiki/Solanine (looks like not in harful quantities though) Jul 1, 2015 at 6:08
  • Indeed. All the nightshades, which a tomato is, contain solanine. But usually not in significant amounts. Jul 1, 2015 at 8:12

In general I agree with the excellent answer by Willem, but when it comes to potatoes it does make sense to cut off any green parts. There have been quite a few stories about people eating green potatoes, and it's not pleasant.

When it comes to tomatoes, though, it looks like the green bits are safe to eat. Harold McGee pronounces the tomato leaves safe to eat!


In general many (most?) greens are 'poisonous' to some extent. After all, being poisonous is the only defence that a plant has against animals eating it. - Most plants want their fruits/berries to be eaten, but not necessarily their leaves, which they need for survival.

We have, however, developed resistance to (and preference for!) some of these poisons. As Harold McGee points out in the article linked to above, some of the compounds found in basil have been shown to cause cancer in animal experiments. And let's not forget alkaloids like theobromine, caffeine and nicotine, that are poisonous in high doses, but can be beneficial in moderate amounts.

Remember sola dosis facit venenum. - The dose makes the poison.

  • Good point about the potatoes, I'll update my answer to include it. Jun 29, 2015 at 15:09

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.