Green tomatoes contain the alkaloid toxin called solanine, which is why they are poisonous.
How does this piece of information relate to Jon Avnet’s 1991 film “Fried Green Tomatoes” in which fried green tomatoes are presented as a specialty in the Whistle Stop Café, or the fact that in some areas of Europe, pickled green tomatoes and jams are produced from green tomatoes? Are they poisonous or not?
It is everything about the amount of poison contained in green tomatoes and what the effects are of eating them.
How Poisonous Are Green Tomatoes Really?
Only the green parts of the tomato contain the alkaloid, so there is only a risk of poisoning from unripe green tomatoes.
Symptoms of poisoning include drowsiness, heavy breathing, stomach problems, and diarrhea. This poisoning will only occur in adults who consume about 200 milligrams of solanine. If large amounts are consumed, it may also cause damage to the central nervous system, cramps, and paralysis. A dose of around 400 milligrams is considered lethal.
Green tomatoes contain around 9 to 32 milligrams per 100 grams, hence, at those levels, one would need to eat over 600 grams of unripe raw tomatoes to experience the first signs of poisoning. It seems very unlikely that someone would do this, especially since solanine tastes very bitter and unpleasant.
Green tomatoes, or unripe tomatoes, only contain 2 milligrams of solanine per 100 grams of tomatoes. At this concentration, it would take 10 kilograms of unripe tomatoes to make it dangerous.
One important note of caution is that solanine is resistant to breakdown from heat so cooked or pickled products made from green tomatoes still contain around 90% of the solanine they contained in their raw form.
Once tomatoes have reached full ripeness, they only contain a maximum of 0.7 milligrams per 100 grams of solanine, which would mean that around 29 kilos of raw tomatoes would have to be consumed in order to get into the area of noticeable poisoning.
Overall, due to the bitter flavor and the relatively low concentration in semi-ripe tomatoes, it is unlikely you will accidentally poison yourself with solanine. Green tomatoes are pickled and fermented in some regions and jams are made from them. These products should be used in moderation since solanine is heat-resistant and the bitter taste is covered by sugar, vinegar, and spices.
What Is Solanine
Solanine is one of the alkaloids. This chemical group also contains several thousand active substances that are contained in plants as a defense mechanism. They include, for example, the colchicine of the autumn timeless, which can be lethal in small doses, and the strychnine of the walnut. But these alkaloids also consist of capsaicin, which is responsible for the spicy effect of chili and hot peppers, or the morphine of the sleep monkey, which is used for pain therapy. Substances from several of these elements are used in medicine in small doses of a few milligrams. It usually becomes harmful if the parts of the plant containing the substances are consumed or otherwise consumed in large quantities.
Solanine Is A Protection Mechanism Of Immature Fruit Plants
To protect themselves from plant predators in the animal kingdom, fruit-bearing plants, in particular, take special precautions. When it comes to the tomato, it’s camouflage and a chemical cocktail. The unripe fruits are green, so they are more difficult to see among the leaves of the plant. Only when the fruit has ripened in the sun far enough so that they are able to propagate the plants do they turn red or yellow, depending on the variety. For example, a toxic alkaloid called solanine is present in green immature tomato fruit as a bitter taste that deters animals from eating these fruits before they are ripe.