Research Article
Determining Nitrate and Nitrite Content in Beverages, Fruits,
Vegetables, and Stews Marketed in Arak, Iran
Mohammad Rezaei,
1
Ali Fani,
2
A. Latif Moini,
2
Parisa Mirzajani,
2
Ali Akbar Malekirad,
3
and Mohammad Rafiei
2
1
Department of Food Safety and Hygiene, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
2
Arak University of Medical Sciences, Arak, Iran
3
Payame Noor University, Tehran, Iran
Correspondence should be addressed to Ali Fani; drfani321@yahoo.com
Received 5 July 2014; Revised 1 December 2014; Accepted 8 December 2014; Published 25 December 2014
Academic Editor: Julian Blasco
Copyright © 2014 Mohammad Rezaei et al. Tis is an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly
cited.
Background and Objectives. Presence of excessive nitrite and nitrate in foodstuf can have toxic and carcinogenic efects on humans.
Tis study is aimed at measuring nitrate and nitrite in diferent foodstufs available in Arak city market, Iran, in 2013. Methods.
Totally 323 samples including stew (102 samples), beverage (116 samples), fruit (55 samples), and vegetables (50 samples) were
randomly collected and analyzed according to ofcial AOAC method 973 and ISO 6635 through spectrophotometric method.
Results. Average concentration of nitrate and nitrite in the samples was 6.58–136.76, 1.52–38.22 mg kg
−1
or liter, respectively.
Presence of nitrate and nitrite was confrmed in all samples. High levels of nitrate and nitrite were observed in celery and ghormeh
stew; and lower level of nitrate and nitrite was found in traditionally produced vinegar, verjuice, and tomato. Conclusions. It was
found that the mean values for nitrite in investigated products were higher than ADI levels of WHO.
1. Introduction
Nitrate and nitrite ions are ubiquitous in the environment
and naturally found in plant foods as a part of the nitrogen
cycle. Vegetables are the original source of dietary nitrate;
however, wide variations in nitrate levels have been observed
depending on the type of vegetable, its source, conditions of
cultivation, and storage [1]. Te amount of available nitrate in
soil (depending on the content of artifcial fertilizer) appears
to be major factor determining the nitrate content in vegeta-
bles [2]. An estimated daily dose of nitrates consumed by man
reaches 75–100 mg, of which 80–90% come from vegetables
and 5–10% come from water [3]. Nitrate in drinking water
usually comes from contamination of ground water caused by
fertilizer, animal, or human waste [4]. Nitrate is converted in
mammalian systems (through bacterial and mammalian enz-
yme action) to nitrite and then reacts with amines, amides,
and amino acids to form N-nitroso compound. While nitrate
does not have direct carcinogenic efects on humans, nitrite
and N-nitroso compounds are known to be biologically active
in mammalian system [1]. Nitrate by the enzyme “nitrate red-
uctase” (in the saliva, in the stomach, and everywhere in
the human body where pH is low) converts to nitrite; nitrite
reacts with hemoglobin and produces methemoglobin which
enables transporting of oxygen at the cellular level. Newborn
organisms are very sensitive to methemoglobinemia because
they have an immature “methemoglobin reductase system”
[5]. Nitrate and nitrite as the sodium or potassium salts are
used as additives in meat products to provide color, taste and
protect against microorganisms; however, excessive use of
these substances can cause toxicity and carcinogenic efect
[6]. High dietary intakes of nitrate and nitrite have been
implicated in the etiology of Human gastric cancer based on
epidemiology and clinical studies [7]. In the stomach, nitrite
reacts with amines and amides; therefor stomach is exposed
to the risk of endogenous N-nitroso compound synthesis, as
stomach acid reacts with catalyses nitrosation. High nitrate
intake has been found to be associated with gastric cancer in
England, Colombia, Chile, Japan, Denmark, Hungary, and
Italy [8]. Te WHO’s ADI for nitrate is of 222mg/day for
Hindawi Publishing Corporation
International Scholarly Research Notices
Volume 2014, Article ID 439702, 5 pages
http://dx.doi.org/10.1155/2014/439702