Nitrate Contents of Some Highly Consumed Products on Sale in Wholesale Fruit and Vegetable Markets in Spring and Winter in District 4, Tehran, Iran

Background and Aim: Healthy food and nutrition have always been a serious concern of human beings. In this regard, food safety is extremely important. As an example, nitrates in foods may affect their safety. The purpose of this study was to investigate the nitrate contents of highly consumed food products (potatoes, tomatoes and onions) on sale in wholesale fruit and vegetable markets (Heravi, Mellat and Lavizan) in District 4 of Tehran, Iran. Materials and Methods: Samples of the foods were collected in winter and spring, and their nitrate content was measured spectrophotometrically. The SPSS-20 software was used for data analysis. Results: The results showed that there was a statistically significant difference between the vegetables nitrate contents in winter and spring. The nitrate content of onions in the spring in the Heravi market and that of potatoes in the winter in the Lavizan market were higher than the respective standard, while that of tomatoes was less than the standard in both seasons. Conclusion: The nitrate content in the samples was in most cases below the respective standard, indicating that the vegetables on sale in the wholesale markets in Tehran were acceptable as regards nitrate content (at least in spring and winter).