Worth knowing about natural plant toxins
Plants are tied to their location and have no means of escape. Nevertheless, they are not defenceless against attack.
On the one hand, plants have ‘mechanical’ defence systems such as spines, glandular hairs or thorns to defend themselves against ‘predators’. On the other hand, they have poisons to expel pests.
Many plants are generally safe and nutritious for consumption. However, you should be careful when you prepare and collect them. It is also essential to know which toxins plants may contain. Thorough washing, trimming, and attention during preparation are imperative.
Toxins in vegetables or berries
The glycoalkaloid content, a collective term for plant toxins in potatoes, tomatoes, and aubergines, varies according to ripeness and variety. As do flowers, stems, and leaves, green, unripe vegetables contain such toxins in high concentrations.
The spectrum of nightshade plants is extensive, from ornamental plants to tobacco, tomatoes, and potatoes. These plants contain natural poisons that protect against pests and pathogens—for example, solanine in potatoes and tomatine in tomatoes.
How dangerous are toxins in nightshade plants?
Green indicates toxicity. Only ripe vegetables should be consumed. Severe cases of poisoning are sporadic. Symptoms include a scratchy throat and digestive problems. However, an intake of approximately one milligram of glykoalkaloid per kilogram of body weight can lead to drowsiness, restlessness or rapid breathing.
Potatoes contain the alkaloids solanine and chaconine, particularly in the skin. Solanine is mainly found in green spots, germ buds and the skin. Green spots or tiny germ buds should be removed (do not use potatoes with many sprouts), as solanine is not destroyed by cooking or in the digestive system.
Solanine is a toxin and a slightly bitter-tasting substance that is not readily soluble. For example, this substance is a natural protective agent for the potato plant against predators. Exposure to light in the field or during storage promotes green spots on potatoes. Germination is also encouraged by exposure to light and excessively warm storage temperatures. Potatoes should, therefore, always be stored in a cool, dry and dark place. Solanine is formed primarily under the influence of light. Potatoes should also be peeled. The cooking water should not be reused, either. Solanine is water-soluble and heat-resistant.
However, potatoes are ordinarily harmless. Sweet potatoes are not actual ‘potatoes’ nor nightshade plants.
Tomatoes contain the natural plant protection substance tomatine, especially in their stems and leaves. This glycoalkaloid, found in the shoots, leaves, flowers, and green, unripe fruits of the nightshade plant, is toxic to insects and fungi.
Are green tomatoes harmful? The quantities of tomatine in unripe tomatoes are harmless to humans, so small amounts can be consumed. Nevertheless, allowing green tomatoes to ripen for a few days and removing the stalk is better. Tomatin is rarely found in ripe tomatoes. However, unusual tomato varieties, such as the ‘Green Zebra, ’ ‘Evergreen, ’ and ‘Green Grape, ’ remain green or greenish when ripe.
Another example is the aubergine, which also contains solanine, the so-called poison of the nightshade family. The vegetable is not suitable for raw consumption. Aubergines still hard and not quite ripe should ripen a little first to reduce the solanine content. Please don't overcook them, and heat them gently. There is a wide range of healthy aubergine recipes. After washing and before preparing them, it is advisable to salt aubergine slices (sea salt), leave them to steep well and then pat them dry. This removes water and bitter substances, and the aubergine absorbs less fat when fried. In addition to solanine, nightshade vegetables contain lectins and, depending on their vulnerability, can be replaced by other vegetables.
Black elderberry. The berries contain magnesium and potassium, B vitamins and vitamin C. Together with other valuable ingredients such as flavonoids, they support essential bodily functions. Balancing minerals strengthens the immune system. However, raw elderberries also contain the toxin sambunigrin, which can lead to digestive disorders. Therefore, elderberries should be briefly heated at eighty degrees. This toxin is particularly abundant in unripe fruits. Harvesting the elderberries only when the berries are fully ripe is crucial. No more green spots should be present. Well-ripened berries contain less sambunigrin but should still not be eaten raw.
Over thousands of years, plants have developed individual defence mechanisms against pests. Therefore, when eating them, please exercise caution. In general, avoid unripe vegetables and berries.
Note: However, other aspects of plant toxins must be considered. Do potatoes and tomatoes even help fight cancer? (You might have a search or AI chat)