Toxicants Occurring Naturally in Food, National Academy of Sciences, Washington, D.C. 1973:558-572
Photosensitizers in foods are reviewed. Foods which cause a phototoxic reaction in animals are also examined. The main photosensitizers occurring in human food, namely furocoumarin compounds, and psoralens are discussed. The plants which can produce the photosensitizing toxins include Hypericum-perforatum (St. John's wort), Fagopyrum-esculentum (buckwheat), Sclerotinia- sclerotiorum mold on celery handled by workers, and Tribulus. The toxins produced by these plants act chiefly through exposure to sunlight. Animals or humans placed in the dark are not nearly as affected by the toxins. In some of the plants, there is a second toxin which produces liver effects, such as constriction of the bile duct, which causes the primary toxin to build up. The structure of the toxins, the toxic dose, and the test system used to to identify the nature of the phototoxic effect are reviewed. Chemical structures of phototoxic compounds are illustrated. The authors suggest that because coumarins are volatilized near the boiling point of water, boiling foods may greatly reduce the amount of toxic materials ingested, preventing humans from ingesting toxic doses.
Toxicants Occurring Naturally in Food, National Academy of Sciences, Washington, D.C.