Nitrate and nitrite content in organically cultivated vegetables.

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 cadmium­Griess 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%.

Fatty acids and carotenes in some ber (Ziziphus jujuba Mill) varieties.

Several jujube varieties from the southeast of Spain were analyzed for fatty acid and carotene contents. Triglycerides having medium-chain fatty acids were most abundant in all samples. The main fatty acids were 12:0 (18.3 +/- 9.97), 10:0 (12.5 +/- 19.0), 18:2n6 (9.27 +/- 7.26), 16:1n7 (8.50 +/- 5.77), 16:0 (7.25 +/- 4.35), and 18:1n9 (5.34 +/- 2.52) on total saponifiable oil. The fruits yield 1.33 +/- 0.17 g/100 g saponifiable oil on a dry weight basis. Fatty acid profiles of fruits were found to be influenced by their developmental stage. Multivariable data analyses show that the samples could be grouped on the basis of their fatty acid content. Carotenes were found to be in good agreement with other fruits, varying from 4.12 to 5.98 mg/100 g on a dry weight basis. The contribution to vitamin value reach a mdium of 38 microg RE/100 g on a fresh weight basis.