I’ve read, occasionally, that olives right off the tree are inedible; they need to be pickled in brine before they’re fit to eat. The Wikipedia article on olives – http://en.wikipedia.org/wiki/Olive_(fruit) – makes no mention of this. Is it true?
What about cereals? In a Soviet WWII movie, Fate of a Man, I once saw the hero, a soldier hiding out from the Germans, strip some grains of wheat from the stalk with his bare hands, roll away the chaff, and eat the raw grains. Well, I’ve eaten tabouli with what appeared to be raw bulghur (cracked wheat) in it, so I guess that’s possible. But what about rice? I would not think of trying to eat raw the rice one buys from a supermarket – but it occurs to me that just-harvested rice, not yet dried for storage, might (or might not) be edible raw. After all, you can’t eat dried pasta, but you could probably eat raw fresh-made pasta (unless it’s made with eggs – raw eggs might give you salmonella poisining). Does anyone know?
What other vegetables, fruits, nuts, grains, etc., require some kind of cooking or other treatment before they’re safe/fit to eat?
Actually, according to Jared Diamond in “Guns, Germs, and Steel”, most acorns were just plain inedible, due to high tannin content. It was the occasional mutant tree that produced 'corns without tannins, which made them palatable.
Cashew nuts are pretty cool. Technically, you can eat them right of the tree, but only if you shell them cleanly. If not, toxin from the shell gets on it.
Y’know, this idea that undercooked eggs are gonna kill you is just completely overblown. Raw eggs are no big deal. Yeah, a few people out of 250 million might get a tummyache every year from eating raw eggs, but they’re certainly not poisonous, especially if you’re a healthy adult.
Pokeweed, an edible green common in the South, is OK when you eat the green, new shoots. But once the plant ages and the shoots turn red, the plant becomes poisonous. So it’s kinda iffy. But it is a great green, grows wild all over the place and has kept a lot of Southern bellies full in lean times (should those lean times occur in March, April and May, when the plant is young).
Plantains. They won’t do you any particular harm raw, but as my grandfather found out when he mistook them for bannanas, they taste like starchy wood. I can’t think of any instance where plantains are (intentionally) eaten straight from the tree.
You can’t eat bananas right off the tree? I wish someone had told me because I’ve done it numerous times with absolutely no ill effects.
As your link says, bananas ripened on the tree become starchy and bland. That doesn’t make them in any way inedible. In parts of SE Asia sweet bananas are considered a defect and a sign that the fruit isn’t fresh because it was picked unripe and left to ripen off the tree.
So bananas definitely don’t qualify.
Fresh olives are intolerably bitter. AFAIK they aren’t poisonous, but given the taste I doubt anyone has ever eaten enough to find out.