Evaluation of nitrate and nitrite contents of some alliums

Abstract

In this study, the nitrate and the nitrite contents of some alliums which are widespread consumed were determined. Totally, 80 samples of vegetables were analyzed. These samples were onions (white, yellow, red and green), garlic and leek collected from 10 different locations in Samsun cities of Turkey. The nitrate was spectrophotometrically assayed with the formation of diazo compound through the reduction of nitrate to nitrite with cadmium acetate solution and zinc powder and then treatment with Griess reagent. Nitrite values of the samples were determined by no addition of zinc powder. Both leaves and white parts of green alliums were studied. The highest nitrate content was found in the white parts of green onions (1711.50 +/- 1067.89 mg kg(-1)), and it was followed by green parts of green onions (1354.49 +/- 1233.62 mg kg(-1)), white parts of leek (963.93 +/- 352.82 mg kg(-1)), green parts of leek (803.70 325.62 mg kg(-1)), garlic (68.77 +/- 83. mg kg(-1)), yellow onions (26.99 +/- 21.29 mg kg(-1)), red onions (13.38 +/- 14.47 mg kg(-1)) and white onions (10.68 +/- 6.22 mg kg(-1)), respectively. The highest nitrite content was white parts of green onions (14.58 +/- 4.32 mg kg(-1)), and it was followed by green parts of green onions (9.47 +/- 3.35 mg kg(-1)), garlic (7.85 +/- 1.82 mg kg(-1)), white parts of leek (6.58 +/- 1.83 mg kg(-1)), green parts of leek (4.75 +/- 1.40 mg kg(-1)), red onions (2.12 +/- 0.53 mg kg(-1)), yellow onions (1.58 +/- 0.54 mg kg(-1)) and white onions (1.12 +/- 0.59 mg kg(-1)), respectively. As a result of this study, the highest nitrate and nitrite concentrations were found in leafy alliums.