Nitrate and nitrite content in organically cultivated vegetables

Abstract

The nitrate and nitrite content of leaf vegetables (Swiss chard, sea beet, spinach and cabbage), "inflorescence" vegetables (cauliflower) and fruit vegetables (eggplant and vegetable marrow) grown with organic fertilizers have been determined by a modified cadmium–Griess method. Samples were purchased from organic food stores as well as collected directly from an organic farm in Madrid (Spain). Nitrate levels were much higher in the leaf vegetables (especially Swiss chard species; average over the different samples and species of 2778.6 ± 1474.7 mg kg(-1)) than in inflorescence or fruit products (mean values between 50.2 ± 52.6 and 183.9 ± 233.6 mg kg(-1)). Following Swiss chard species, spinach (1349.8 ± 1045.5 mg kg(-1)) showed the highest nitrate content, and nitrite was found above the limit of detection in some samples only (spinach, 4.6 ± 1.0 mg kg(-1); sea beet, 4.2 ± 0.7 mg kg(-1) and Swiss chard, 1.2 ± 0.4 mg kg(-1)). Some vegetables (spinach, cabbage and eggplant) had lower nitrate content in the samples harvested in summer, showing the influence of climatic conditions on the nitrate levels in a plant. The samples taken directly from the organic farm, with the exception of eggplant, had higher or slightly higher average nitrate values than samples purchased in the organic food stores, ranging from 117 to 1077%.

Biochar, Vermicompost, and Compost as Soil Organic Amendments: Influence on Growth Parameters, Nitrate and Chlorophyll Content of Swiss Chard (Beta vulgaris L. var. cycla)

“…The authors reported a lower nitrate content in organic (from 546 to 1274 mg kg −1 Fw) than mineral fertilized (from 780 to 2113 mg kg −1 Fw) Swiss chard. Matallana González et al [73] in samples of Swiss chard collected directly from an organic farm in Spain found values of nitrate content (2630.4 mg kg −1 Fw) near or higher than the ones purchased from organic food stores (2595 mg kg −1 Fw).…”

Nutritionally Optimized, Culturally Acceptable, Cost-Minimized Diets for Low Income Ghanaian Families Using Linear Programming

“…Alternatively, under the USD 1.9 constraint, a nutritionally adequate solution in rural areas demands the inclusion of wild foods ( Table 4 ). However, their use is limited due to: seasonality, local availability, considerable time consumption for harvest and their content of potentially toxic substances such as nitrates [ 43 ].…”

Organic Carrot (Daucus carota L.) Production Has an Advantage over Conventional in Quantity as Well as in Quality

“…However, we found lower nitrate content in ORG at equal N fertilization levels in both systems. Mineral fertilizer used in CON treatments directly provides nitrate, while compost is slowly decomposable and nitrogen releases gradually [55]. In general, carrot is classified as a vegetable with a low nitrate content, with the average being 200-500 mg kg −1 [56].…”