GREEN VEGETABLES AS POTENTIAL SOURCE OF NITRATES AND NITRITES FOR THE HUMAN ORGANISMS

摘要

In the human body the nitrates affect the digestive tube but also the kidneys. By reduction they form the nitrites who determine methaemoglobinaemia and cancer. The nitrites toxicity is more dangerous for babies and small children. Nitrates and nitrites disturb the metabolically processes of B1, B6 and A vitamins and of the beta-carotene. They also have a toxic effect upon the hypophyses and thyroid. The highest quantities of nitrates in human body came from the vegetables ingestion and so also from water. Large amounts of nitrates in plants are funded in leafs, stems and the smallest in roots. Nitrites are accumulated in fresh vegetables in reduced amounts. The largest quantity of nitrites in human body is due to nitrates reduction. Nitrites content in vegetables are determined by spectrophotometric method, using Peter-Griess reagent at wave length 520 nm. The nitrates content from samples is determined by the same method, after the reduction to nitrites with cadmium powder. As in case of nitrates, in case of nitrites we observe the same trend: lowest amounts in summer season and higher amounts during the winter. The highest concentration of nitrites was determined in case of spinach in the summer and in the winter too and the lowest ones in case of lettuce.