Nitrates and nitrites can be naturally found in many foods, including milk. Due to their toxicity there is a maximum level allowed for these compounds in foods. In the present study, nitrate and nitrite levels were evaluated in raw milk samples produced in conventional and organic systems. Samples were collected from farms of the Depressão Central of Rio Grande do Sul, Brazil. The average levels of nitrate and nitrite in samples (n=45) were 6.65±0.84mg/L and 1.76±0.17mg/L, respectively. Milk produced in the organic system exhibited 7.08mg/L nitrate and 1.61mg/L nitrite, while milk produced in the conventional system exhibited 6.36 and 1.87mg/L, respectively. Nitrate and nitrite levels in raw milk were not affected by the production system, the period of collection, milking shift or the site of production (farm).
raw milk; conventional system of production; organic system of production; contaminants
