Glycosides are derivatives of sugars. Breakdown products of natural glycosides next sugars (mostly glucose) are: hydroquinone, purines, methyl ester of salicylic acid, hydrogen cyanide. Glycosides are generally colorless and bitter in taste, soluble in water and alcohol. Some of the glycosides exert a strong effect on the human body. The most dangerous are glycosides that contain cyanide, which blocks the respiratory chain at the cell level. Such glycosides are in oilseed cake, some feeds, seeds of bitter almonds, plums, apricots, peaches.
Saponins are amorphous substances soluble in water and strongly decrease the surface tension. Increase foaming and stabilizing fats, because sometimes they are used for the manufacture of soft drinks and halvah. Their use in many countries is prohibited because they cause blood hemolysis, inflammation of the ileum. They are also in legumes (antinutritious substances).
Tannins are polyphenols combination with glucose. Found in coffee and tea, in small quantities in mushrooms. Tannin forms insoluble compounds with heavy metal salts - so it can reduce the absorption of iron, copper, etc. The protein forms insoluble complexes by causing inhibition of digestion in the stomach.
For the organic acids include: malic acid, citric acid, lactic acid, succinic acid. In its structure does not contain nitrogen, and their physical-chemical features are similar to carbohydrates. Give characteristic taste and smell, may also be a source of energy. Some organic acids produced during fermentation products (souring cucumbers, cabbage, milk). During combustion, these acids often a base, which is involved in maintaining acid-base balance.