NITRATE ACCUMULATION IN AUTOCHTHONOUS VARIETIES OF VEGETABLES

摘要

The purpose of the current paper was to estimate intake of nitrates and nitrites by 4 species of vegetables and to study the relation between the growing methods using different levels of fertiliser for vegetables and the degree of nitrate accumulation. Nitrates occur naturally in vegetables and plants. 80 vegetable samples provided by S.C.D.L. Buzau during months May and June 2008 were analysed for nitrite and nitrate concentration using an UV rapid enzymatic method where the nitrate is reduced in nitrite by NADPH in the presence of the nitrate reductase. In the growing methods we used 5 fertiliser treatments where the doses varied as follows: V1=0 kg N /ha, V2=25 kg N /ha, V3=50 kg N /ha, V4=75 kg N /ha, V5=100 kg N /ha. The levels of nitrate and nitrite in the leafy vegetables samples were the highest among all the samples studied. Cucumbers and tomatoes had accumulated very low amounts of nitrate during the treatment, but significant differences among the treatments could be observed. The highest contribution of the nitrate in human body is attributed to the consumption of salad and spinach.