Measuring nitrate and nitrite concentrations in vegetables, fruits in Shiraz

Abstract

Nitrosamine is derived from nitrate and it seems as one of the factors and causes of gastrointestinal cancer in adults and Methemoglobinemia (blue baby syndrome). Eighty percent of nitrate enters to the body through vegetables and fruits, so in this study nitrate concentration in available vegetables and fruits at Shiraz was determined and compared with standard limit. At first, Shiraz city was divided to several regions in geographical terms, then samples were purchased; these samples were used by citizens more during spring and winter, then samples were extracted. Nitrate reading was done using a spectrophotometer Palin test (Photometer 7100) and accuracy was measured by a conventional spectrophotometers. SAS and Excel were used to draw diagrams and statistical calculations. Statistical comparisons showed value of nitrate and nitrite in leafy vegetables is more than fruits and cucurbits. Average concentration of nitrate is more in potato and is low in onion among cucurbits. Among fruit and vegetables, highest concentration of nitrate is allocated to eggplant and lowest concentration of nitrate is allocated to tomato. Among leafy vegetables, highest concentration is allocated to mint and lowest concentration is allocated to savory. Generally, concentration of nitrate in all samples was lower than WHO limit. © JASEM