The excessive presence of nitrate in foodstuff can be potentially toxic and carcinogenic to humans. This is because about 80% of the nitrate that enters the human body comes from vegetables. Therefore, the present study determined the nitrate content in agricultural products commonly consumed by Iranians. A total of 222 samples of 19 different varieties of these products, including vegetables (171 samples), cereals (42 samples), and legumes (9 samples), were randomly collected from major grocery stores in different cities in Iran between September 22 and December 15, 2020. The methods of HPLC-UV were used to evaluate the nitrate content. The detection limits (L.O.D.) and limit of quantification (L.O.Q.) were 0.071 and 0.22 mg kg-1, respectively. As a result, the mean nitrate levels in the different samples varied from 1042.50 mg kg-1 in lettuce to 49.90 mg kg-1 in wheat. Potato also had a higher mean nitrate concentration than the standard level. In addition, products such as tomatoes, eggplant, spinach, herbs, and lettuce had significantly lower average nitrate concentrations than the typical values. Moreover, the average nitrate concentration was highest in the central region (492.7 mg kg-1). In contrast, the lowest average nitrate concentration was in the northern region (121.7 mg kg-1) (P < 0.05). Moreover, the highest average nitrate concentration (468.52 mg kg-1) was found in the vegetable group and the lowest in the cereal group (50.40 mg kg-1) (P < 0.05). Taken together, this information could allow the establishment of a database for the quantification of nitrate exposure and its risk-benefit determination in the Iranian population. Manuscript profile

Nowadays, due to the increased consumption of meat products, investigation of their additives such as nitrite seems necessary. Nitrate in combination with salt has a synergistic characteristic against pathogenic microorganisms. Nitrite combines with protein, fats, and volatile and non-volatile compounds in meat and plays an important role in flavoring meat products. Excessive use of this substance leads to a more dangerous compound called nitrosamine. The present study aimed to investigate the nitrate content of meat products with different levels of meat. Health risk assessment toward nitrite was also calculated. A total of 108 samples of meat products in various commercial brands were collected and analyzed from retail markets of Tehran to detect the amount of nitrite in them. Meat products in terms of their meat percentage were divided into three categories under 50%, 50% to 70%, and more than 70%. Estimated daily intake (EDI), based on per capita consumption rate and hazard quotient (HQ) for adults and children were also estimated. The mean concentration of nitrite in meat products with >70% meat, 50-70%, and <50% were 28.04, 30.07, and 27.02 mg kg-1, respectively that did not resemble any significant difference (p>0.05). The results indicated that the levels of nitrite were lower than permissible levels. The calculated HQ was less than 1 for meat products. However, this value was more for children. So is necessary to take precautions any over-consumption of this type of product in children. Manuscript profile