As everyone knows, sprouted potatoes are inedible because they produce solanine when they sprout. But you may not know that eggplants also contain this substance, which is called solanine. Solanine has effects such as strengthening the heart, lowering blood pressure, inhibiting cancer cells, and inhibiting microorganisms, and it is one of the sources of eggplant's health benefits; however, high intake by the human body can also lead to poisoning.
Scientific research has found that the solanine content in unripe eggplants is higher than in ripe ones. The solanine content is high in eggplants harvested during the peak picking season, but low in those harvested when the plants are about to be pulled up. Measurements have also found that the depth of the eggplant's skin color is greatly related to its solanine content: purple eggplants have a high content, while green ones have a low content. In other words, the darker the color of the eggplant, the higher its solanine content.
However, solanine is not present in the skin of the eggplant, but mainly in the flesh. Therefore, trying to avoid ingesting the toxin by peeling the eggplant is ineffective. At the same time, solanine is basically insoluble in water, so methods like blanching or boiling cannot remove it. The only way is to control the intake. Fortunately, the solanine content in eggplants is low, with the highest varieties not exceeding 0.8 milligrams per gram of dry weight. Converted to fresh eggplant, you would need to eat about 450 grams of this high-solanine variety to reach an intake of 25 milligrams, which could cause discomfort such as nausea and vomiting. It would take 400 milligrams of solanine to be potentially fatal to an adult. Therefore, under normal circumstances, eating half a jin (250 grams) of eggplant in a meal will not cause any trouble.
The reason people hear that raw tomatoes are poisonous is also because of solanine. Eating one 80-100 gram pure green tomato can reach a solanine content that makes a person feel nauseous and unwell. However, green tomatoes are not as scary as they seem; as long as you stop eating them, the symptoms will gradually subside. There is a life-threatening risk only if you eat more than 1.15 kilograms.