Survey of Nitrate and Nitrite Levels of Fresh Vegetables in Turkey

摘要

In this study, the nitrate and nitrite contents of a total 258 samples of 7 different vegetables (tomato, carrot, head lettuce, leaf lettuce, iceberg, parsley and spinach) sold in Ankara markets in Turkey were determined during the period of 6 months. These vegetables are supposed to provide the major contribution to the intake of nitrate from the diet. Nitrite was estimated spectrophotometrically and nitrate after reduction to nitrite with cadmium column. The highest content of nitrate was found in parsley (1513.36 mg kg 1) followed by spinach (1456.04 mg kg 1), crisphead lettuce (1042.81 mg kg 1), butterhead lettuce (914.22 mg kg 1), iceberg (623.38 mg kg 1), carrot (190.03 mg kg 1) and tomato (11.06 mg kg 1). The mean nitrite values of spinach, parsley, crisphead lettuce, iceberg, butterhead lettuce, carrot and tomato were determined as 2.31, 1.78, 0.98, 0.92, 0.84, 0.65 and 0.36 mg kg 1 in fresh weight, respectively.