عنوان مقاله [English]
Background and Objectives
Khuzestan Province is one of the most important areas that provide vegetables throughout winter and spring in Iran. The vegetables are mainly picked up in the afternoon, so it cannot be supplied to the market. In this time of the day, the minimum amount of nitrate is accumulated in leafy vegetables, with a gradual increase throughout the night. On the other hand, its highest level is in the early hours in the morning. The purpose of this study is to evaluate nitrate and nitrite accumulation in vegetables produced in different areas of Ahwaz during winter and spring.
Materials and Methods
This experiment was conducted in a randomized complete block design arranged in a split-split-plot design with three replications in the Department of Horticulture, College of Agriculture, Shahid Chamran University of Ahvaz. In the treatments viz. first to third harvest dates (1): February 6, 2016, (2):March 4, 2016 and (3): April 7, 2016 respectively were the main factors and nine vegetable species (including coriander, parsley, mint, fenugreek, chard, spinach, leeks, dill and watercress) kept in sub plot, three vegetable production areas in Ahvaz were arranged in sub plot in sub plots and three fields were selected in each of these areas. Before and after cultivation, all planting, harvesting and harvesting operations were carried out on the same field in the selected fields. The concentration of nitrate was measured by the method introduced by Cataldo et al. (1975) and the nitrite concentation was measured via the method of Abu-Dayeh (2009). The data were analyzed using SAS software and the mean comparison was calculated using Duncan's multiple range tests at a probability level of 5%.
Nitrate and nitrite contents of the produced vegetables were different depending on various regions, harvesting time and vegetable species. The highest nitrate content was observed in parsley fromthe first harvest in the southern region of Ahwaz (4.4 mg/kg-1 dry matter) and the lowest amount of nitrate was recorded in watercress from the third harvest in the northern region of Ahvaz (1.4 mg/kg-1 dry matter). Also, the highest nitrite content was observed at the first harvest in the westhern region of Ahwaz in mint and the lowest amount of nitrate was recorded in the second harvest in the northern region of Ahvaz in chard. In winter, the environmental conditions in Ahwaz are suitable for the growth and development of leafy vegetables (Boroujerdnia et al., 2007); however, soil conditions provide manganese uptake by plants. Moreover, high light intensity is another factor which can decrease nitrate in leafy vegetables. The number of cloudy days in Ahwaz is very low; therefore, the number of sunny days with high radiation intensity is high in winter. This phenomenon greatly reduces the content of nitrate in leafy vegetables.
The amounts of nitrate and nitrite content in various species of vegetables produced in three regions of Ahvaz during the cold season were much lower than the standard figures. Therefore, we can conclude that the quality of vegetables produced in Ahvaz is very high in terms of nitrite and nitrate contents.
Abu-Dayeh A. G. (2009). Determination of nitrate and nitrite content in several vegetables in tulkarm district. M.Sc thesis of Environmental Sciences, An-Najah National University, Palestinian.
Alexander RB, Smith RA, Schwarz GE, Boyer EW, Nolan JV, Brakebill JW (2008) Differences in phosphorus and nitrogen delivery to the Gulf of Mexico from the Mississippi River Basin. Environment Science Technology Journal, 42(2):822–830
Amr, A. and Hadidi, N. (2001). Effect of cultivar and harvest date on nitrate (NO3) and nitrite (NO2) content of selected vegetables grown under open field and greenhouse conditions in Jordan. Journal of Food Composition and Analysis, 14(1), 59-67.
Boroujerdnia, M. and Alemzadeh Ansari, N. (2007). Effect of different levels of nitrogen fertilizer and cultivars on growth, yield and yield components of romaine lettuce (Lactuca sativa L.). Middle Eastern and Russian Journal of Plant Science and Biotechnology, 1(2), 47-53.
Cataldo, D. A., Maroon, M., Schrader, L. E. and Youngs, V. L. (1975). Rapid colorimetric determination of nitrate in plant tissue by nitration of salicylic acid. Communications in Soil Science and Plant Analysis, 6(1), 71-80.
Colla, G., Kim, H. J., Kyriacou, M. C. and Rouphael, Y. (2018). Nitrate in fruits and vegetables. Scientia Horticulturae, 237, 221-238.
Correia, M., Barroso, A., Barroso, M. F., Soares, D., Oliveira, M. B. P. P. and Delerue-Matos, C. (2010). Contribution of different vegetable types to exogenous nitrate and nitrite exposure. Food Chemistry, 120(4), 960-966.
EU Scientiﬁc Committee for Food. (1995). Opinion on nitrate and nitrite expressed on 22 september 1995. Annex 4 to document III/56/95, CS/CNTM/NO3/20-FINAL. Brussels: European Commission DG III.
European Food Safety Authority (EFSA). (2008). Nitrate in vegetables‐scientific opinion of the panel on contaminants in the food chain. EFSA Journal, 6(6), 689-768.
Hsu, J., Arcot, J. and Lee N. A. (2009). Nitrate and nitrite quantification from cured meat and vegetables and their estimated dietary intake in Australians. Food Chemistry, 115(1), 334-9.
Jafari, R., Farzan, A. and Aziz Zadeh, A. (2000). The amount of nitrate and nitrite in some vegetables produced in Esfahan city. Research in Medical Sciences, 6(2), 123-126. [In Farsi]
Jalali, M. (2005). Nitrates leaching from agricultural land in Hamadan, western Iran. Agriculture, Ecosystems & Environment, 110(3), 210-8. [In Farsi]
Kaiser, B. N., Gridley, K. L., Brady, J. N., Phillips, T. and Tyerman, S. D. (2005). The role of molybdenum in agricultural plant production. Annals of Botany, 96(5), 745-754.
Kiani, S. H. and Gheytasim, M. (2016). Evaluation of nitrate and nitrite accumulation in vegetables exposed on ShahreKord's markets. Journal of Food Hygiene, 4(20), 67-79. [In Farsi]
Leszczynska, T., Filipiak-Florkiewicz, A., Cieslik, E., Sikora, E. and Pisulewski, P. M. (2009). Effects of some processing methods on nitrate and nitrite changes in cruciferous vegetables. Journal of Food Composition and Analysis, 22(4), 315-321.
Lorenz, O. A. (1978). Potential nitrate levels in edible plant parts [Vegetables]. Retrieved fromhttp/www.agris.fao.org/agris-search/search.do?recordID=US19780340390.
Lundberg, J. O., Weitzberg, E., Cole, J. A. and Benjamin, N. (2004). Nitrate, bacteria and human health. Nature Reviews Microbiology, 2(7), 593-602.
Malakouti, M. J. (2010). Sustainable agriculture and increase performance by optimizing the use of fertilizers in Iran. Tehran: Sana Press. [In Farsi]
Pavlou, G. C., Ehaliotis, C. D. and Kavvadias, V. A. (2007). Effect of organic and inorganic fertilizers applied during successive crop seasons on growth and nitrate accumulation in lettuce. Scientia Horticulturae, 111(4), 319-325.
Pirsaheb, M., Sharafi, K. and Moradi, D. (2012). A survey on nitrite and nitrate levels in vegetables and cucurbits cultivated in northern and western plains of Kermanshah city in 2012. Journal of Food Hygiene, 3(1), 77-78. [In Farsi]
Santamaria, P. (2006). Nitrate in vegetables: Toxicity, content, intake and EC regulation. Journal of the Science of Food and Agriculture, 86(1), 7-10.
Shahlaei, A., Alemzadeh Ansari, N. and Dehkordie, F. S. (2007). Evaluation of nitrate and nitrite content of Iran Southern (Ahvaz) vegetables during winter and spring of 2006. Asian Journal of Plant Sciences, 6(8), 1197-203.
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