ABSTRACT
Nitrates are widespread in the environment and occur naturally in plant-based foods as a part of the nitrogen cycle. In the case of animal-based food, these compounds may be present in the raw material mainly as a result of contaminated feed or water. Moreover, nitrates and nitrites are used as additives in meat and cheese processing to improve their quality and protect against microbial contamination and chemical changes. Among the foods of plant origin, vegetables are the main source of nitrates in the human diet. Some vegetables such as spinach, beet, radish, and lettuce are considered to contain high concentrations of nitrates. However, researchers show that nitrate concentrations of plant-based food vary, depending on many factors, including biological properties of plant culture, light intensity, type of soil, temperature, humidity, frequency of plants in the field, vegetation period, harvesting time, storage time, and fertilization. Therefore, data on the nitrate content of vegetables from different countries/regions can differ significantly. Due to the high consumption of vegetables, they are the main source of nitrates in the human diet. Processed meats and cheese are another sources of nitrates and nitrites in the human diet because the meat and milk industry uses nitrates/nitrites as antimicrobial agents against Clostridium tyrobutyricum, C. butyricum (milk processing), and C. botulinum (meat processing). Having more and more knowledge about the content of nitrates/nitrites in food from different countries, it is also possible to determine the consumer exposure to these food compounds. Knowledge about the content of nitrates in plant and animal-based food makes it possible to determine the consumer exposure to these food compounds, as nitrate intake with food is associated with some health risks for consumers.
