Abstract
The leaves of lettuce are very reach source of vitamins, macro and microelements and biologically active compounds. However, these plants contain also anti-nutritional compounds as nitrates and nitrites which levels depend on growth and storage conditions. The aim of this study was to determine the effect of foliar application of CaCl2 treatment before harvest on nitrate and nitrite accumulation, in whole leaves and leaf blades in fresh and stored lettuce. The experimental material was lettuce cv. Omega which was grown in greenhouse. The solution of CaCl2 was used in the concentration of 0.1M and 0.2M on plants, 20 and 10 days before harvest. After harvest, some plants were directly analysed, while the remaining plants were cold-stored at 4ºC for 7 and 14 days in dark polyethylene bags.
The higher concentrations of nitrate and nitrite was noticed in fresh whole leaves than in leaf blades. The foliar CaCl2 treatment of plants before harvest contributed to a statistically decrease in the nitrate levels and nitrite increase in whole leaves in fresh plants. The greatest changes were noticed after using of 0.1M CaCl2 solution on plants. During the storage time of lettuce in the non-treatment plants were observed the higher concentration of nitrates and nitrites in leaf blades compared to fresh plants. The CaCl2 treatment on lettuce caused a significant decrease in the nitrite concentration of whole leaves of plants stored for 7 days, while in the leaf blades higher nitrite amounts were accumulated in lettuce which was stored in cold conditions during all experimental time.
References
Amr A., 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. J. Food Comp. Anal., 14, 59–67.
Bharti N., Singh R.P., Sinha S.K., 1996. Effect of calcium chloride on heavy metal induced alteration in growth and nitrate assimilation of sesamium indicum seedlings. Phytochem., 41 (1), 105–109.
Bruning-Fann C.S., Kaneene J.B., 1993. The effects of nitrate, nitrite and N-nitroso compounds on human health: a review. Vet. Human. Toxicol., 35, 521–538.
Burns I.G., Zhang K., Turner M.K., Meacham M., Al-Redhiman K., Lynn J., Broadley M.R., Hand P., Pink D., 2011. Screening for genotype and environment effects on nitrate accumulation in 24 species of young lettuce. J. Sci. Food Agric., 91, 553–562.
Chung J.-C., Chou S.-S., Hwang D.-F., 2004. Changes in nitrate and nitrite content of four vegetables during storage at refrigerated and ambient temperatures. Food Addit. Contam., 21 (4), 317–322.
Correia M., Barroso A., Barroso M.F., Soares D., Oliveira M.B.P.P., Delerue-Matos C., 2010. Contribution of different vegetable types to exogenous nitrate and nitrite exposure. Food Chem., 120, 960–966.
Gajda-Wyrębek J., Jarecka J., Kuźma K., Mirkowska M., 2009. Zawartość azotanów V w sałacie i szpinaku w Polsce w latach 2007–2008. Bromat. Chem. Toksykol., 42, (3), 519–524.
Huber S.C., Bachmann M., Huber J.L., 1996. Post-translational regulation of nitrate reductase activity: a role for Ca2+ and 14-3-3 proteins. Trends Plant Sci., 1(12), 432–438.
Lundberg J.O., Feelisch M., Bjorne H., Jansson E.A., Weitzberg E., 2006. Cardioprotective effects of vegetables: Is nitrate the answer? Nitric Oxide, 15, 359–362.
Majkowska-Gadomska J., Arcichowska K., Wierzbicka B., 2009. Nitrate content of the edible parts of vegetables and spice plants. Acta Sci. Pol., Hortorum Cultus, 8(3), 25–35.
Mensinga T.T., Speijers G.J.A., Meulenbelt J., 2003. Health implications of exposure to environmental nitrogenous compounds. Toxicol. Rev., 22, 41–51.
Michłojć Z., Szewczuk C., 2003a. Teoretyczne aspekty dolistnego dokarmiania roślin. Acta Agrophysica, 85, 9–17.
Michałojć Z., Szewczuk C., 2003b. Praktyczne aspekty dolistnego dokarmiania roślin. Acta Agrophysica, 85, 19–29.
Michłojć Z., Horodko K., 2006. Wpływ dokarmiania pozakorzeniowego wapniem na plonowanie i skład chemiczny papryki słodkiej. Acta Agrophysica, 7(3), 67–679.
Pannala A.S., Mani A.R., Spencer J.P.E., Skinner V., Bruckdorfer K.R., Moore K.P., Rice-Evans C.A., 2003.The effect of dietary nitrate on salivary, plasma and urinary nitrate metabolism in humans. Free Rad. Biol. Med., 34 (5), 576–584.
Pennington J.A.T., 1998. Dietary exposure models for nitrates and nitrites. Food Control, 9(6), 358–395.
PN-92/A-75112 (neq ISO 6635-1984) Fruits, vegetables and derived products. Determination of nitrites and nitrates content.
Prasad S., Chetty A.A., 2008. Nitrate-N determination in leafy vegetables: study of the effects of cooking and freezing. Food Chem., 106, 772–780.
Ruiz J.M., Rivero R.M., Garcia P.C., Baghour M., Romero L., 1999. Role of CaCl2 in nitrate assimilation in leaves and roots of tobacco plants (Nicotiana tabacum L.). Plant Science 141, 107–115.
Santamaria P., 2006. Nitrate in vegetables: toxicity, content, intake and EC regulation. J. Sci. Food Agric. 86, 10–17.
Saure M.C., 1998. Causes of tipburn disorder in leaves of vegetables. Sci. Hort., 76, 131–147.
Steinmetz K.A., Potter J.D., 1991. Vegetables, fruit and cancer. I. Epodemiology. Cancer Causes Control 2, 325–357.
Tamme T., Reinik M., Roasto M., Juhkam K., Tenno T., Kiis A., 2006. Nitrates and nitrites in vegetables and vegetable-based products and their intakes by the Estonian population. Food Addit. Contamin., 23(4), 355–361.
Van Velzen A.G., Sips A.J.A.M., Schothorst R.C., Lambers A.C., Meulenbelt J., 2008. The oral bioavailability of nitrate from nitrate-rich vegetables in humans. Toxicol. Letters, 181, 177–181.
Walker R., 1990. Nitrates, nitrites and N-nitrosocompounds: a review of the occurrence in food and diet and the toxicological implications. Food Addit. Contam. 7, 717–768.
Downloads
Download data is not yet available.
