lj@ewj01.UUCP (Leonard Jacobs) (08/14/85)
From net.cooks come the following: > Not going out and picking one's own saffron is excellant advice. May I > suggest the book, Poisonous Plants of the United States by W. C. Muenscher, > Macmillan Publishing? You'll be interested to find that certain delicacies > have inedible parts or seasons. Also, that beet and turnip greens store > toxic levels of potassium nitrate if grown in soils too rich in it. Warning: > the book's main subject is livestock rather than primate poisoning. > > Sukie Crandall The question re potassium nitrate is an interesting one. Does anyone have any factual information on permissible levels of nitrates in foods? I understand that there are Federal guidelines for permisible levels of nitrates in drinking water--something like 40 ppm--but that similar levels do not apply to foods. According to some farmers/gardeners, nitrate levels in green vegetables exceed 40 ppm in many vegetables, organic and not, due to the immaturity of the plants when picked. This is a result of the nitrates necessary for growth not being completely utilized by the plants if they are picked early. Concentrations are apparently higher in vegetables which come from another region since they must be picked prematurely in order to avoid early wilting. The levels are also highest in the white parts of the vegetables, e.g., the center of iceberg lettuce, since photosynthesis changes the nitrates. Is there a possible danger in consuming high levels of nitrates, and what are permissible levels in our foods? In some cases nitrates do convert to nitrites. What determines this? If anyone has any information on this please either post or respond. Thanks -- Len Jacobs East West Journal harvard!bbnccv!ewj01!lj