03/20/2024
Bulbs contain 8-14% sugars (fructose, sucrose, maltose, polysaccharide inulin), proteins (1.5-2%), vitamins (ascorbic acid), flavonoid quercetin, enzymes, saponins, mineral salts of potassium, phosphorus, iron, etc. ., phytoncides.
Yellow, purple and white onions
Green onion leaves contain sugars, proteins, and ascorbic acid. The bulbs and leaves contain essential oil, which gives them a specific smell and pungent taste, sulfur-containing compounds, iodine, organic acids (malic and citric), mucus, pectin substances, and glycosides.
Onions stimulate the secretion of digestive juices, have a diuretic and some calming effect. Onion phytoncides determine the bactericidal and anthelmintic properties of the plant.
Pain in the eyes and lacrimation when cutting onions occur due to the presence in the cells of the onion of 1-propenyl-l-cysteine sulfoxide (PRENCSO, a cysteine derivative) and the enzymes alliinase [en] (alliin lyase) and LFS (lachrymatory-factor synthase, factor synthase lacrimation). When the integrity of cells and their vacuoles is disrupted, PRENCSO is converted by alliinase into 1-propenesulfonic acid, which in turn, with the help of LFS, is converted into a volatile lacrimation factor - 1-sulfinylpropane[en]. Getting on the mucous membrane of the eyes, it excites nociceptors, which causes lacrimation.