Table 1.
Distribution and levels of nitrate (mg kg−1) in the different types of vegetables in this research.
| Sample | No. of Samples | Mean ± SD (mg kg−1) | Median (mg kg−1) | Concentration Range (mg kg−1) | Maximum Levels (mg kg−1) (Regulation 1258/2011) | |
|---|---|---|---|---|---|---|
| Harvested 1.10.–30.3. | Harvested 1.04.–30.9. | |||||
| Lettuce | 21 | 1035.3 ± 732.6 | 1020.1 | 169.7–3184.2 | 5000 (UC) 4000 (OA) | 4000 (UC) 3000 (OA) |
| Swiss chard | 17 | 1913.6 ± 1126.6 | 2055.4 | 233.4–3558.4 | - | |
| Rucola | 10 | 3041.4 ± 974.7 | 3073.2 | 1674.8–4526.3 | 7000 | 6000 |
| Mixed salad | 11 | 548.0 ± 269.1 | 199.2 | 54.6–952.6 | - | |
| Lamb’s lettuce | 7 | 1086.5 ± 703.5 | 1273.8 | 36.1–2175.5 | - | |
| Spinach | 8 | 1056.5 ± 742.0 | 976.8 | 168.5–2350.9 | 3500 | |
| Root vegetables | 15 | 178.8 ± 396.4 | 32.2 | <LOQ–1534.8 | - | |
| Cabbage | 7 | 533.6 ± 406.0 | 484.1 | 13.5–1040.1 | - | |
| Total | 96 | |||||
SD, standard deviation; UC, grown under cover; OA, grown in the open air; LOQ, limit of quantitation = 1 mg kg−1.