Nitrites tend to bind to hemoglobin, the main transport vehicle for oxygen. In such a situation, hemoglobin turns into a special form - methemoglobin - and loses its ability to deliver oxygen to tissues. What does this look like in practice? With a significant concentration of methemoglobin in the blood, a person breathes, but at the same time oxygen does not enter the tissues, as, for example, during suffocation.

The severity of poisoning depends on the amount of nitrates ingested and the level of methemoglobin in the blood. However, in any case, exceeding the permissible concentration of methemoglobin has a negative impact on well-being.

Worth paying attention! The most vulnerable in this situation are babies under one year old, especially the first 3 months. The fact is that the “anti-nitrate” protective mechanism does not work in such crumbs. Due to their age, babies have few enzymes that facilitate the reverse conversion of methemoglobin into normal hemoglobin.

Signs of nitrate poisoning

Symptoms of poisoning are largely determined by the amount of nitrates ingested and the level of methemoglobin formed. It should be said that nitrate poisoning associated with the consumption of early vegetables and fruits is now rare. Much more often, specialists encounter nitrate poisoning when a baby uses well water: as a drink and when preparing infant formula with it. The first signs of poisoning, as a rule, are malaise, lethargy of the baby and refusal to eat. Older children may complain of headaches. With significant formation of methemoglobin (defective hemoglobin), the child’s skin loses its natural pink color and becomes gray and bluish.

On a note! Often in everyday life, diarrhea and vomiting are considered a typical sign of nitrate poisoning. However, most often such symptoms are associated with gastritis or intestinal dysfunction due to excessive consumption of fiber (plant fibers) or fats that are used to flavor salads (sour cream, mayonnaise).

How to help a child?

For all cases of illness in young children, the following rule applies: if the baby’s condition is not clear to you, consult a doctor! Parents should be alert to symptoms such as unexplained lethargy, refusal to eat or drink, and changes in skin color. If the baby is not vomiting and swallowing is preserved, you should give him one age-appropriate dose of any sorbent: activated carbon, enterosgel, atoxil, smecta, etc. While waiting for the ambulance, the child can be given small amounts of water. It is important to get to a specialist as soon as possible. In large cities, care for children with poisoning is provided in toxicology or intensive care departments, in small cities - in the pediatric department.

It is important! A baby with diarrhea and vomiting needs a medical examination also because it is important to determine the true cause of such manifestations. A baby with diarrhea loses water and therefore needs a more intensive drinking regimen.

Read more about nitrates and their harm to the child’s body in the magazine “Mom and Me” No. 7/2013, you can buy it

Search materials:

Number of your materials: 0.

Add 1 material

Certificate
about creating an electronic portfolio

Add 5 material

Secret
present

Add 10 materials

Certificate for
informatization of education

Add 12 materials

Review
free for any material

Add 15 materials

Video lessons
for quickly creating effective presentations

Add 17 materials

Municipal state educational institution secondary
comprehensive school with in-depth study of individual subjects
Urban settlement Demyanovo Podosinovsky district Kirov region
Nitrates in
food
Work completed
11th grade student
Chernova Elvira
Teacherconsultant
Nogteva S.V.,
biology teacher

village Demyanovo 2016
Content
I.
Introduction……………………………………………………………………………….3
Working with literature……………………………………………………………..5
I.1. General characteristics of nitrates……………………………..5
I.2. Nitrates in food…………………………………..6
I.3. Maximum permissible concentrations of nitrates in products
nutrition……………………………………………………………7
I.4.
The effect of excess nitrates on human health……………...7
I.5. How to protect yourself from nitrate poisoning…………….….9
I.6. Ways of nitrates entering the human body………………..9
I.7. Permissible standards of nitrates for humans……………………11
II. Research……………………………………………………..12
II.1. Method for detecting nitrates……………………………12
II.2. Experience……………………………………………………………13
II.3. Research results……………………………………..14
III.
Conclusion………………………………………………………..15
References………………………………………………………16
Appendix No. 1…………………………………………………………….17
Appendix No. 2……………………………………………………………………………….18
Appendix No. 3……………………………………………………………………………….19
Appendix No. 4……………………………………………………………………………….21
Appendix No. 5……………………………………………………………………………….23
Appendix No. 6……………………………………………………………………………….26
2

Introduction
It is well known that the most valuable thing a person has is his health, which
impossible to buy and which is primarily affected by problems such as
unfavorable environmental conditions, smoking, alcoholism. However, not
We should also forget that our health largely depends on proper
nutrition.
Lately we have often heard the word “nitrates” discussed
people in shops, at the market. We found out in the dictionary what the word means
"nitrates". Nitrates are salts (compounds) of nitric acid or products
metabolism of nitrogenous substances of any living organism. Nitrates are formed in
plants during growth, as well as after the use of nitrogen fertilizers.
If used incorrectly, mostly vegetables and fruits
accumulate amounts dangerous to the human body
nitrates
The relevance of the work is related to the problem of nitrate content in
food products, since excess amounts can lead to
a number of negative consequences for humans.
Problem: I want to learn how to determine nitrates in food, but
at the moment I don’t know how to do this. (Appendix No. 1)
There are several ways to solve this problem:
Talk to the chemistry teacher.
Study additional literature.
Find on the Internet. (Appendix No. 2)
Hypothesis: If people learned to identify nitrates in foods
nutrition, then I can do it too.
My proposed project is research. Option for the future
product there will be conclusions from the study.
The results of my research can be used
any
a person who will be interested in this topic.
3

During the course of the project I will become familiar with the methods
determination of nitrates, find out what chemicals are necessary for
this.
Project goal: To master the methodology for determining nitrates and
examine their content in vegetables and fruits purchased in stores and
grown in our own garden plot. (Appendix No. 3)
Tasks:
Find information about nitrates
1.
2. Studying the literature on the effects of excess nitrates on human health
3. Find ways to determine nitrates
4. Find the necessary products for the experience
5. Conducting a chemical experiment
6. Creation of a reminder “Let’s “Save” from Nitrates at Home”
7. Present the results of the work
4

I. Working with literature
1.1 General characteristics of nitrates
Nitrates are salts of nitric acid, for example: NaNO3, KNO3,
NH4NO3, Mg(NO3) 2. They are normal metabolic products
nitrogenous substances of any living organism - plant and animal,
therefore, there are no “nitrate-free” products in nature. Even in the body
person per day is formed and used in metabolic processes 100 mg and
more nitrates. They existed even before the origin of man. First
they started talking about nitrates in our country in the 70s, when in Uzbekistan
Several mass gastrointestinal poisonings occurred due to watermelons from
for their excessive feeding with ammonium nitrate. However, talk about
The health risks of nitrates continue. However, the problem is not the
nitrates, but in how much of them enters the human body.
According to the World Health Organization, it is safe
The amount of nitrates per 1 kg of human body weight is considered to be 5 mg. That is,
an adult can receive about 350 mg of nitrates without any
health consequences.
Plants have the ability to absorb fertilizer-rich
soils have much more nitrogen compounds than they need for development. IN
As a result, only part of the nitrates is synthesized into plant proteins, and
the rest enter the human body in its pure form through fruits, roots and
vegetable leaves. Subsequently, some nitrates are quickly eliminated from the body, but
others form various chemical compounds. Some of these
compounds are harmless and even beneficial for the body, but others turn
salts back into nitric acid, and this is what the applied
nitrates are harmful to health.
Excess nitrogen fertilizers leads to a decrease in the quality of plant
products, deterioration of its taste properties, decreased endurance
5

plants to diseases and pests, which, in turn, forces
farmers to increase the use of pesticides. Especially sharply
the negative effect of fertilizers and pesticides appears when
growing vegetables indoors. This happens because in
in greenhouses, harmful substances cannot evaporate freely and
carried away by air currents. After evaporation, they settle on plants.
1.2 Nitrates in food
What are the main sources of dietary nitrates? Practically this
exclusively herbal products.
In animal products (meat, milk), the nitrate content is very
insignificant. But nitrates are added to finished meat products for the purpose of
improving its consumer properties and for longer storage
(especially in sausages).
In plants, the maximum accumulation of nitrates occurs during the period
greatest activity during fruit ripening. Therefore, unripe vegetables
(zucchini, eggplant) and potatoes, as well as early ripening vegetables can
contain more nitrates than those that have reached normal harvest maturity.
In addition, the nitrate content in vegetables can increase sharply when
improper use of nitrogen fertilizers (not only mineral, but also
organic). For example, when applying them shortly before harvesting.
However, different plants also have their own individual characteristics.
“Accumulators” of nitrates are known. These include green vegetables: lettuce,
rhubarb, parsley, spinach, sorrel. Beets can accumulate up to 140 mg
nitrates (this is the maximum permissible concentration), and some varieties and
more. But other vegetables contain significantly less nitrates. Fruits, berries
and melons contain very little nitrates (less than 10 mg per 100 g of fruit).
Nitrates are distributed unevenly in plants. In cabbage, for example,
nitrates accumulate most in the stalk, in cucumbers and radishes - in
surface layers, in carrots it’s the other way around.
Now that everything is known about food nitrates, let's try to imagine
their real health hazard. Let's consider the main sources
nitrates Let's start with green vegetables (lettuce, parsley, dill, etc.). Their
6

consumption almost rarely exceeds 100 g per day, and most often around
50 g, i.e. with one serving you can get less than a third of the safe value
daily dose. Now let's move on to the beets. It is known to be consumed
only in boiled form. Because during cooking (40%) and stripping (10%)
half of the nitrates are lost, and catering recommends a serving
boiled beets in 125 g, then with beets we can get 100 mg of nitrates
(less than a third of the daily dose). Boiled potatoes and cabbage
consumed in portions of 300 g. Taking into account losses during cleaning and cooking
processing with one serving of these products we can consume about 60 mg
nitrates. (Appendix No. 4)
1.3 Maximum permissible concentrations of nitrates
in products
Product
Potatoes
Early white cabbage
Late white cabbage
Early carrots
Late carrots
Tomatoes
cucumbers
Content,
mg/kg
250
900
500
400
250
150/300
150/400
Beetroot
Bulb onions
Leafy vegetables
(lettuce, parsley, dill)
Sweet pepper
Zucchini
Melons
Grape
Watermelon
1400
80
2000
200
400
90
60
60
1.4 Effect of excess nitrates on human health
7

It is now generally known that nitrates have a high
toxic to humans and farm animals.
Nitrates under

by the action of an enzyme
nitrate reductase
are reduced to nitrites, which interact with hemoglobin
blood and oxidize 2-valent iron into 3-valent iron. As a result
the substance methemoglobin is formed, which is no longer able to tolerate
oxygen to tissues and organs, which may result in suffocation.
1.
A threat to life begins to arise when the level
methemoglobin in the blood reaches 20% or higher. Therefore it is violated
normal respiration of cells and tissues of the body (tissue hypoxia), in
As a result, lactic acid and cholesterol accumulate and drop sharply
amount of protein.
2. Nitrates are especially dangerous for infants, because their enzyme
the basis is imperfect and the restoration of methemoglobin to hemoglobin is ongoing
slowly.
3. Nitrates contribute to the development of pathogenic (harmful) intestinal
microflora that releases toxic substances into the human body
toxins, resulting in toxicity, i.e. poisoning of the body.
The main signs of nitrate poisoning in humans are:
blueness of nails, face, lips and visible mucous membranes;
nausea, vomiting, abdominal pain;
diarrhea, often with blood, enlarged liver, yellowness of the whites of the eyes;
headaches, increased fatigue, drowsiness, decreased
performance;
shortness of breath, increased heart rate, up to loss of consciousness;
 in case of severe poisoning – death.
4. Nitrates reduce the content of vitamins in food, which are included in
the composition of many enzymes stimulates the action of hormones, and through them
affect all types of metabolism.
5. Pregnant women experience miscarriages, and men experience decreased
potency.
6. With prolonged intake of nitrates into the human body (let
even in small doses) the amount of iodine decreases, which leads to
enlargement of the thyroid gland.
7. It has been established that nitrates have a strong influence on the occurrence of cancer
tumors in the gastrointestinal tract in humans.
8

8. Nitrates can cause a sharp dilation of blood vessels, as a result
which lowers blood pressure.
To the group of increased risk of damage to the body by nitrates
In addition to children, the compounds also include persons suffering from diseases
cardiovascular and respiratory systems, pregnant women, elderly
people who, even without exposure to salts of nitric or nitrous acid
there is insufficient oxygen supply to organs and tissues.
Sensitivity increases in mountainous areas, when contained in the air
nitrogen oxides, carbon monoxide, carbon dioxide. Also increases their toxicity
drinking alcoholic beverages.
1.5How to protect yourself from nitrate poisoning
Everyone knows that vegetables bought at the market may contain
nitrates, which are very harmful to the human body. But you won't bear it
The same grown vegetables are sent to the laboratory for testing. But experts believe
that the presence of nitrates in vegetables can be easily determined by eye.
Laboratory tests show that most often nitrates
found in oranges, lemons, thick-skinned watermelons, brightly in carrots
orange, in dark green or quickly yellowing cucumbers, in pumpkin with
wavy stripes. In addition, often large amounts of nitrates
found in red grapes with a grayish haze, beets with a twisted
tail up and potatoes with curly skin.
But don’t be too upset if vegetables with this description
ended up with you.
Proper cutting of each vegetable will help you get rid of nitrates
vegetables:
Carrots - need to be cut by a third from the tops side.
Beetroot - should be boiled in an aluminum pan, before
cutting off the tail and cutting it lengthwise into two parts.
It is enough to peel the potatoes and then you can cook them, since
Nitrates are mainly contained in potato skins.
Citrus products oranges, lemons and others need to be cut:
lemons along and oranges across, then you need to hold them a few
9

seconds in air, and connect the halves for several hours, this
the procedure will help get rid of nitrates. (Appendix No. 5)
1.6 Routes of nitrates entering the human body
Nitrates enter the human body in various ways.
1. Through food products of plant and animal origin.
Nitrates mainly accumulate in roots, root crops, stems, petioles
and large veins of leaves, much less of them in fruits.
2. Through drinking water. Drinking water from groundwater contains
up to 200 mg/l of nitrates, much less in water from artesian wells.
Nitrates enter groundwater through various chemical fertilizers
(nitrate, ammonium), from fields and from chemical plants
production of these fertilizers.
3. Through medications and tobacco.
4. Some nitrates can be formed in the human body itself when
his metabolism.
The best fruits for our table are those grown in open ground, in
greenhouse berries and vegetables are low in minerals and vitamins, because they are beneficial
The plant produces substances when it receives enough sunlight.
There are always more nitrates in large-sized fruits. Their size and weight
catch up with repeated fertilizing and other agrotechnical
techniques.
Meanwhile, not all plants accumulate nitrates equally. More
In total, “poisons” like to “settle” in watermelons, melons, cabbage, potatoes,
parsley, dill, black radish, lettuce, spinach, sorrel, rhubarb,
celery, carrots, radishes, beets. But in beans, beans, grains, garlic,
currants, cherries, apples and plums, nitrates are found only in small
doses
Nitrate content in cauliflower heads after two weeks
storage is reduced by approximately 40% compared to the original level. IN
During onion storage, the nitrate content in the bulbs is practically zero
changes.
With products of animal origin into the human body, as
As a rule, a small amount of nitrates is supplied. Nevertheless,
the accumulation of nitrate nitrogen in them is due, apparently, to one
10

on the other hand, by using animal feed with high levels of nitrates, and on the other hand,
the other is by their entry into products during the technological process
processing.
Another way nitrates enter the human body is associated with
food additives and preservatives.
Chemical food preservation has its
there are many substances in the arsenal, some of them are nitrates and nitrites.
Sodium nitrate (E 251) and potassium nitrate (E 252) are allowed for use
mixed with table salt (preventing the development of
microorganisms, to give a beautiful (not gray) color to sausages).
Used in the production of cheese, meat and fish products. Some
states refuse to add nitrates to meat products due to their
uncontrolled conversion to nitrites.
Potassium nitrite (E 249) and sodium nitrite (E 250) are extremely poisonous.
The lethal dose is 32 mg per 1 kg of body weight, that is, about 2 grams.
I.7 Permissible standards of nitrates for humans
The permissible daily dose of nitrates for an adult is
325 mg per day. As is known, the presence of
nitrates up to 45 mg/l. Recommended food intake where
drinking water is used (tea, first and third courses), approximately 1.0–1.5 l,
maximum – 2.0 liters per day. Thus, with water an adult can
consume about 68 mg of nitrates. Therefore, for food products
257 mg of nitrates remain.
Studies have shown that the toxic effects of dietary nitrates
products appears weaker than those contained in drinking water, approximately
1.25 times. It is actually safe to consume 320 mg in food
nitrates per day.
The permissible nitrate content for an adult is 5
mg per 1 kg of body weight. The human body copes relatively easily with
daily dose of nitrates equal to 15200 mg, and the maximum permissible dose is
500 mg.
For an adult, the toxic dose is 600 mg.
10 mg of nitrates will be enough to poison an infant.
11

In the Russian Federation, the permissible average daily dose of nitrates is
312 mg, but in the spring it can actually be 500800 mg/day.
Minimum and maximum accumulation of nitrates in vegetables
Amount of nitrates in mg/kg
Minimum
30
10
115
10
306
20
70
Maximum
1520
362
606
200
8969
359
3520
Products
Cabbage
Potato
Carrot
Onion
Beet
cucumbers
Radish
II. Study
2.1. Nitrate detection method
In analytical chemistry there are several methods for qualitative
determination of nitrates and nitrites in solution.
1 way:
3 drops of diphenylamine
5 drops of conc. sulfuric acid
A few drops of the test solution
(Appendix No. 6)
Method 2:
10 ml of test solution
1 ml of solution (10% Griess reagent solution, 12% acetic
acid)
(Appendix No. 6)
12

3 way:
10 ml of test solution
1015 drops of alkali
50 mg zinc dust
(Appendix No. 6)
4 way:
1 ml of test solution
1 ml saline solution
1 ml rivanol solution
(Appendix No. 6)
Researching all the methods for determining nitrates, I chose 1 and 4, since
This is the most accessible way of research.
2.2 Experience
I am preparing all the necessary reagents for the study. I'm squeezing
juice from products (cucumber, onion, carrot, potato, orange, apple): teru
on a fine grater, then squeeze the juice from the pulp with gauze. Then I cook
rivanol solution by mixing rivanol with distilled water. In
I fill the second flask with diphenylamine and sulfuric acid. I'll spend the first one
experiment, I add 1 ml of rivanol solution and saline solution to
juice. This test did not show the presence of nitrates in the products, so I
I'm conducting a second experiment. I add 1 drop of diphenylamyl solution to the juice. IN
This experiment changed the color of some components (cucumber, carrots,
potatoes, orange, apple), which proves the presence of nitrates in the data
products.
13

2.3Research results
Vegetables and fruits purchased in the store and
grown on a personal plot. The results of the experiment are listed in the table.
14

Products
Cucumber
Onion
Carrots (domestic)
Potato
Orange
Potatoes (homemade)
Apple
Color change
+
­
+
+
+
­
+
According to the study, the leader in nitrate content was
cucumber and orange. The concentration of nitrates in them exceeds the maximum
permissible level. Homemade carrots contain some
nitrates, because nitrogen-containing fertilizers were used. Study
showed that the nitrate content in onions and home potatoes is not
exceeds the norm.
Conclusion
During the work on the project, the set goal and objectives were achieved.
This work gave me the opportunity to express myself. While creating the project, I learned
15

work correctly with information, and also acquired the skills to determine
nitrates in food.
It was especially good to collect and analyze all
information.
The difficulties were in the practical part, since I determined nitrates in
the first time, but in the future, I think, these difficulties will not arise.
I believe that my work deserves a good mark because
there may have been some inaccuracies, it was done for the first time and not
professionally.
My project is finished.
At the end of the work, I made the following conclusions:
1. Nitrates are contained in all products, regardless of whether they are purchased
or not, but in certain quantities.
2. The presence of nitrates can be determined by the appearance of the product.
3. Excessive amounts of nitrates can be harmful to health.
person.
4. You can reduce the amount of nitrates in foods at home
conditions.
5. There are many ways to determine nitrates in food
in laboratory conditions.
Bibliography
16

1. Nitrates in food [Electronic resource]/.http://produkt
pitaniya.ru/nitratyfood
2. Permissible concentrations of nitrates [Electronic resource]/.
http://him.1september.ru/
3. The effect of nitrates on health [Electronic resource]/.
http://prodobavki.com/
4. Permissible norms of nitrates for humans [Electronic resource]/.
http://vocmp.oblzdrav.ru/
17

Deducing the problem
Annex 1
Desired situation: Actual situation:
Know how to determine I can imagine, but I don’t know
nitrates in food how to do it
1. Have a skill 1. No skills
2. Research on my own 2. I can’t research on my own
Contradiction:
I want to have the skills to determine nitrates in food, but
I don't have any at the moment.
Problem:
I want to learn how to determine nitrates in food, but for now
I don't know how to do this at the moment.
Project type: research
18

Appendix 2
Problem Analysis
Solutions
+
­
1.Talk to
chemistry teacher
1. The teacher knows how
determine nitrates
1.
2.Explore
additional
literature
2. Lots of information
2.
3.Find on the Internet
3.There are many ways
3.Not all information
faithful
Conclusion:
After analyzing all the ways to solve the problem, I settle on
all three methods, because I think that at the moment all solutions
feasible.
19

Target
Master
methodology
definitions
nitrates and
explore on
their content
in vegetables and
fruits,
purchased in
store and
grown on
own
vegetable garden
area
Appendix 3
Resources
 Information
 Labor
Project planning
Tasks
1.Find
information
about nitrates and
influence on
health
person
Steps
1.1. Ask
chemistry teacher
1.2. Explore
additional
literature
1.3. Find in
Internet
2.Find
ways
definitions
nitrates
3.Find
necessary
products for
experience
2.1. Find in
Internet
2.2. Explore this
literature
2.3. Research
these methods and
choose the most
comfortable
3.1. Buy
vegetables and fruits
3.2. Take home
vegetables
3.3. Buy physical
solution
3.4. Rest
Components
ask
chemistry teacher
 Information
 Labor
 Labor
 Material
20

 Labor
4.Conduct
chemical
experience in
content
nitrates
4.1. Prepare
all necessary
components for
experience
4.2. Conduct
experience
5.1. Develop
memo
5.2. Type
 Labor
5.Create
memo "
"Let's be saved"
from nitrates
Houses"
6. Checkout
results
work
6.1. Write
results
work
 Labor
21

Appendix 4
Based on their ability to accumulate nitrates, plants can be divided into five
groups by content in 1 kg of product:
 more than 5 g (all types of salads, parsley, radishes);
 up to 5 g (spinach, radish, kohlrabi, beets, green onions);
 up to 4 g (white cabbage, carrots, onions);
 up to 3 g (leek, rhubarb, dill, pumpkin);
 less than 1 g (cucumbers, watermelons, melons, tomatoes, eggplants, potatoes).
Nitrates are distributed unevenly in plants:
1) in beets, nitrates are concentrated in the upper part of the root crop - up to
65 %;
2) for carrots in the core - 90% and in the outer part - 10%;
3) in cabbage - in the stalk and thick leaf petioles;
4) in potatoes, small tubers contain more nitrates than large ones,
they are concentrated under the skin;
5) small cucumbers contain less nitrates than large ones; in cucumber
picked in the morning, there are fewer nitrates.
The quality of vegetables depends on many factors, including the input
fertilizers and plant protection products used.
Nitrates are used as fertilizers and are known as nitrates:
sodium (Chilean), potassium (real), ammonia (ammonium) and
calcium (Norwegian). Nitrates are the most important component of plant nutrition,
since the nitrogen they contain is the main building material of the cell.
The ability to accumulate nitrates varies among different crops.
The greatest accumulation is observed in green crops: dill, parsley,
green onions (from 400 to 2500 mg/kg). Significantly less ability to
Tomatoes (10–190 mg/kg), sweet peppers (40–330
mg/kg), eggplants (80–270 mg/kg).
To obtain vegetables with low nitrate content you need
correctly use crop rotation in crop rotation, watering and
optimal sowing or planting density, rational use of fertilizers.
It is known that tomatoes, peppers and eggplants have low accumulation
nitrate nitrogen in fruits, however, there are significant varietal
differences and particular influence are exerted by conditions, primarily
illumination Therefore, dense cropping increases the danger
22

accumulation of nitrates. For the same reason, the content increases
nitrates in greenhouse vegetables.
An important role is played by the form of nitrogen fertilizers used and their timing.
making. Maximum amount of nitrates in vegetable products
accumulates when using ammonium and sodium nitrate, and
minimal - when adding urea and ammonium sulfate.
Nitrogen fertilizing is stopped 1.5 months before harvesting (after 10–15
It is better not to introduce them in July).
The accumulation of nitrates in vegetable products is influenced by
soil moisture. More moderate nitrogen nutrition of plants is observed when
irrigation mode at a level of 80–90% of the highest humidity.
Pesticides must be used with caution, because together with nitrates
they can create an additional unfavorable background. Should be selected
plant varieties that accumulate nitrates to the least extent regularly
destroy weeds, loosen the soil, widely use biological
plant protection products.
Compliance with the above conditions will increase the yield of vegetables.
and improve their quality.
The optimal time for sowing vegetable plants ensures the best
ripening of vegetables and obtaining environmentally safe products.
The concentration of nitrates is affected by shelf life. Research
showed that after six months of storage their amount in root vegetables
decreases by 1.5 - 2 times. Nitrates are almost never found in vegetables,
stored for the winter.
Vegetables should not be stored at elevated temperatures, especially
defrosted. It has been established that the higher the storage temperature and the
The greater the concentration of nitrates, the more intense the process of their
reduction and more nitrites are formed.
For vegetables and fruits, certain maximum values ​​are set
permissible nitrate concentrations (MPC). MPC amount of harmful
substance in the environment that does not have a negative impact
impact on human health or his offspring with constant or
temporary contact with him.
23

Appendix 5
Reducing the nitrate content in products with
storage and culinary processing.
When stored in dry, ventilated warehouses, the level of nitrates in
fresh vegetables decreases. In salted and pickled vegetables it decreases by
account of going into brine. To avoid the formation of nitrites, it is necessary
store clean, dry vegetables without mechanical damage.
Clean vegetables have few microorganisms; dryness limits them
movement, and the lack of damage makes it difficult for them to get
nutrients, including nitrates, from plant cells.
Culinary processing. At this stage you can reduce the content
nitrates, suppress the formation of nitrites and neutralize them.
The nitrate content decreases during cleaning, soaking, and boiling.
When cleaning, the most nitrate parts are separated from the plant and discarded:
cabbage - stalk, upper leaves and leaf veins, cucumber - back
(petiole) part and peel. At high nitrate levels, plants
acquire a bitter taste.
The remaining low-nitrate parts of the plants are soaked in water, which
allows you to reduce the concentration of nitrates by another 25%. Soak it like this:
Vein-cleaned leaves (cabbage) are soaked in large quantities
water for 1-2 hours, then drain the water and pour in new water, soak again 1
-2 hours, leave the vegetables in the third water overnight.
Unfortunately, soaking is effective only for leafy vegetables:
cabbage, sorrel, parsley and so on.
Hot water extract (boiling) is more effective, removing
up to 85% of nitrates from vegetables, including root vegetables (carrots, beets).
The broth must be drained while hot, since when it cools, some of the nitrates
returns from the decoction to the root crop - adsorption occurs.
Preventing nitrite formation comes down to inhibition
vital activity of microorganisms, reducing storage duration
24

finished products. The difficulty is that during cooking
the most favorable conditions for the development of microorganisms are created
- vegetables are chopped, ground, boiled in broth.
In this case, the main means of prevention is to reduce the time
storage All salads, and especially vegetable juices and purees for children, should be
cook or open canned food just before
consumption, If necessary, it is better to store finished products in
refrigerator, and no more than a day. Sterilization (boiling) of juices, soups,
killing microflora, it also suppresses the formation of nitrites.
Here are some tips on how to determine at home
presence of excess nitrates in the product:
1. The increased content of nitrates in watermelons can be recognized by their yellow
veins and compactions in the pulp. Same thing when you eat melons
culture, do not regret leaving the pulp near the rind - that’s where there is more
total nitrates!
2. In carrots, the core turns white when there is an excess of nitrates;
3. Tomatoes have thick skin;
4. Vegetables (sweet peppers, beets, apples and pears) must be peeled,
peel off the peel.
It is known that all vegetables and fruits contain the most nitrates
contained in the peel. In addition, there are more harmful substances in green fruits,
than in mature ones. Plant parts located closer to the surface are also rich in nitrates.
root Simply put, the leaves of parsley, celery and dill contain almost twice as much
less than in the stems, so the stems of herbs should be discarded and
use only leaves.
The surface part of carrots contains 80% less nitrates than its
core. In cucumbers and radishes, on the contrary, the surface layers (peel) are
70% richer in nitrates than the inner one (hence cucumbers are better
clean and cut off the place where they are attached to the stem). In cucumbers, beets,
radishes, besides, you need to cut off both ends, here is the highest concentration
nitrates
Using parts of plants containing the smallest amount for food
nitrates, you can reduce their intake into the body by almost half. This
very important to consider when preparing raw vitamin salads. Except
Moreover, even pre-treatment (mandatory washing and cleaning) will reduce
the amount of nitrates in vegetables by 1015%.
25

With prolonged (for two hours) soaking in water from the leaves
parsley, dill, lettuce, 15-20% of nitrates are washed out. To reduce by 25
30% nitrate content in potatoes, carrots, beets, cabbage,
It is enough to keep them in water for an hour.
In the process of boiling carrots and beets, the most intense
the transition of nitrates into the decoction occurs in the first 30-40 minutes, then the process
practically stops. Potatoes lose up to 80% of nitrates during cooking,
carrots and cabbage up to 70%, beets up to 40%.
The danger of nitrate poisoning does exist. You can
avoid by following these tips:
1. Nitrates are chemically active and even during normal storage
content in fruits decreases rapidly. When washing and cleaning, 10 is lost
15%, during cooking 4070% nitrates;
2. Don’t get carried away with off-season greenhouse vegetables, for example
Eating 2 kg of greenhouse cucumbers at one time can cause
life-threatening poisoning. Watermelon poisoning often occurs and
melons, which are generally not recommended to be purchased before the end of August;
3. Nitrates are highly soluble in water, so beets, zucchini,
potatoes, cabbage, pumpkin and other vegetables must be
cut into cubes and add water 23 times, keeping in it for 510 minutes;
4. Cooking vegetables, pickling, and salting reduce the nitrate content, and
drying, on the contrary, increases;
5. It is better to soak peeled potatoes in a 1% solution for a day.
table salt or ascorbic acid;
6.
It is necessary to remove the top covering leaves of cabbage and
throw away the stalk;
7. Beets and carrots need to be cut off the top and bottom parts
root vegetables;
8. The cucumber needs to be peeled and its tail cut off;
9. Keep in mind that the highest nitrate content (mg/kg)
observed in beets, cabbage, lettuce, parsley;
10. Nitrates accumulate in the following parts of the plant:
 in cabbage – in the stalk;
 in carrots – in the core;
 for cucumbers and zucchini – in the peel;
 in green crops – in the stems.
26

Appendix 6
1 way:
Place three drops of diphenylamine solution on a watch glass, five
drops of concentrated sulfuric acid and a few drops of the test
solution. In the presence of nitrates and nitrithiones, a dark blue color appears
coloring.
Method 2:
To 10 ml of the test solution add 1 ml of a solution consisting of
10% solution of Griess reagent in 12% acetic acid, and heat to 70
80 °C in a water bath. The appearance of a pink color indicates
presence of nitrithiones.
Preparation of Griess reagent. The reagent consists of two solutions.
First dissolve 0.5 g of sulfanilic acid by heating at 50
ml of 30% acetic acid solution.
Second, boil 0.4 g of anaphthylamine in 100 ml of distilled water
water. Add to the colorless solution drained from the blue-violet precipitate
6 ml of 80% acetic acid solution.
Before use, mix both solutions in equal volumes.
3 way:
Add 1015 drops of alkali to 10 ml of the test solution, add
Nitrates
2550 mg zinc dust,
are reduced to ammonia, which is detected by redness
phenolphthalein paper soaked in distilled water and added to
vapors of the test solution.
4 way:
Heat the resulting mixture.
Rivanol reaction. To 1 ml of the test solution add 1 ml
physiological solution and mixed with 1 ml of rivanol solution
(rivanol tablet is dissolved when heated in 200 ml of 8% hydrochloric acid
27

acids). If a pale pink color appears, it means the level of nitrates and
Nitrites in drinking water are unacceptable.
28

Contents of the article:

What to do with fresh products when there are only GMOs around?

Our stomach doesn’t care what genes are in a piece of meat. And talking about GMOs, the definition of GMOs, stickers about GMOs - this is just a business on your illiteracy. There is not a single study proving that GMOs are harmful. The GMO issue is a national scam.

What about nitrates?

Any plant can exist only by utilizing nitrogen. To grow and reproduce, plants need nitrogen. Nitrogen can be taken from the soil. If there is little nitrogen, the plant grows poorly. But it's still growing. Therefore, there are nitrogen fertilizers that are added to the soil, plants grow much faster, and then we eat these nitrates. Nitrate itself is not poisonous. You can eat a kilogram. The peculiarity is that nitrates entering the gastrointestinal tract are converted into nitrites. And nitrites entering the blood in a specific way combine with the hemoglobin molecule, and can cause severe poisoning or chronic oxygen deficiency. It is very dangerous. There is a certain norm that a person can receive no more than 5 mg of nitrates per 1 kg of weight per day. But this is all very clever and incomprehensible. What should you know? There are few nitrates in the leaves, and the closer you get from the leaf to the root, the more nitrates there are. If you take dill or parsley and take the leaves, then there are 2 times less nitrates than in the solid part. Cabbage has the maximum amount of nitrates in the stalk. When a child is given a stalk to chew on, it is done by someone who lacks brains. In relation to cucumbers or watermelon, the closer to the peel, the more nitrates. The thinner, the softer, the less nitrates. What did the smart mother do who bought a watermelon in August? A smart mother understands that it is impossible for a watermelon to grow huge in the month of August without nitrogen fertilizers. Therefore, this watermelon contains a lot of nitrates. But most of them are in the peel. And in the middle, in the pulp, there is the least amount of it. Therefore, if a smart mother was not smart enough not to buy a watermelon in the month of August, she still bought it. Then she will give the child a heart, and she will give a non-heart to the father. Dad is big, and he needs more nitrates. But if the mother sees that the child is gnawing right to the skin, then she will say that this cannot be done. And he will make sure that the child has 2 watermelons, so long as he doesn’t gnaw them to the rind.

And now we have 2 wonderful ways to avoid poisoning children with nitrates.

What can neutralize nitrates?

Nothing. You don't need to eat them. Water in which they can be dissolved can neutralize. Why are potatoes rarely poisoned? Because potatoes are not eaten raw. And when they cook, up to 80% of the nitrates end up in the water. If you boil carrots, nitrates will decrease by 20-30%. If we process and cook, we sharply reduce the amount of nitrates. If you are in doubt about the product, soak it in water for several hours. And the amount of nitrates will decrease by 20-30%.

What is the best water to give to a child?

Bottled mineral water with a neutral taste is the best option. If we doubt the quality of water, it is better to boil the water. When boiling, calcium and phosphorus salts will precipitate, but it is better to give the child calcium gluconate and drink safe water.

Spring water.

You must understand the meaning of the word spring. And if there is a state decision next to this spring, then this water can be used.

Is it possible to give artificially grown champignons to a 4 year old child?

If you know the source of origin of these mushrooms, if the preliminary test on dad was successful, then you can take them in moderate quantities after 4 years.

What foods are dangerous for children under 4 years of age?

These are the products that we cannot process, disinfect, and that we do not have the ability to properly store. For example, a cake with butter cream in the summer. One of the most dangerous products is low-quality canned food, especially homemade. There is one of the most dangerous infections - botulism. This microbe produces poison, and it can only be produced when there is no access to oxygen. The microbe does not reproduce in the presence of oxygen. Those. The jar is hermetically sealed and there is no oxygen there, then it multiplies. If, for example, there is jam, where there is 1 kg of sugar per 1 kg of fruit, or there is a sufficient concentration of salt in canned food, then the microbe does not multiply. But if these are canned foods where disinfection is insufficient, then the microbe can multiply. If the lid is swollen, if the smell is not the same, then you can’t even try it. Botulism is an infection where just touching your tongue is enough to kill you.

How dangerous is it to prepare fermented milk products from unboiled homemade milk?

Really dangerous. Even if it is a verified source. You cannot check how Aunt Klava washes her hands every day, whether her husband Uncle Vasya spat in the milk bucket. There is no daily monitoring. When the director of a dairy kitchen that produces kefir, he knows that if there is some kind of infection there, they will definitely get to him, because half the neighborhood will be poisoned. Therefore, the director will boil the milk a little more than necessary and store it under more stringent conditions than you. Therefore, it is much more difficult to get poisoned with kefir from a dairy kitchen than with homemade kefir. If you boil the milk first and then make kefir, then this is normal.

Should you separate dishes for children and adults?

Not worth it. You don’t think that if you do everything clean for the child, then dad doesn’t deserve it. Dad will also be grateful if the food is prepared with clean hands, in high-quality dishes, from high-quality products. Dad also needs to be taken care of. Another question is that it is very difficult for a child to cook a small portion in his father’s huge saucepan. Therefore, you can have a small saucepan for preparing food for your child. Because children are not prepared 3 days in advance.

How to check the water used for cooking in kindergarten?

Water is something that is beyond the control of parents in kindergarten. You can’t rely on the sanitation station. Because they will always agree with the kindergarten administration. If you are interested in this question, you team up with other mothers, ask to see the water they cook with; if there is no normal water, you supply them with water, buy them filters. The parent community needs to keep an eye on this.

How to properly store and defrost frozen food?

Food should not be defrosted at room temperature. You can’t get a piece of meat in the morning because he’ll come home from work in the evening. They don't do that anywhere. You can defrost it either in the microwave or in the refrigerator. Took it out of the freezer and put it in the refrigerator. You can heat everything in the microwave except breast milk. Tales about the dangers of microwave ovens are inventions of manufacturers of other ovens, not microwave ovens.

Nitrates (salts of nitric acid) are present in all living organisms, both plant and animal. They are ingested with food, are formed as a result of their own chemical processes, and in small quantities serve as an obligatory component of metabolism. Pathological is the excessive intake of nitric acid salts into the body from the outside, most often in vegetables, fruits, water and sausages.

Source: depositphotos.com

Nitrates, also known under the outdated name “saltpeter,” have become widespread in agriculture due to the intensification of production. Adding nitrogenous fertilizers to the soil can increase yields and speed up the process of fruit ripening.

The commercially justified use of high and ultra-high doses of nitrate fertilizers leads to their excessive accumulation in agricultural products. In addition, nitrogen fertilizers increase the mineralization of the soil in which the crop is planted, which results in an additional supply of nitrates to the plant from the soil.

Up to 70% of agricultural products have high levels of nitrates; out-of-season vegetables and melons grown in an unnatural time of year are especially dangerous. When storing crops, the amount of nitrates in plants decreases significantly: in about six months, the concentration of nitric acid salts in potatoes decreases by 4 times, in beets by 1.5, in carrots and cabbage by 3 times.

Of the cultivated plants, the most actively accumulating nitrates are peas, corn, potatoes, beets, watermelon, melon, zucchini, carrots, tomatoes, cucumbers, and greens.

In addition to agriculture, nitrates are widely used in the food industry, especially in the production of sausages. By interacting with the protein myoglobin contained in meat, they give the product an attractive pink color.

Large amounts of nitrates are harmful to the body; their reduction products, nitrous acid salts, or nitrites, pose an even greater danger. The toxicity of nitrites is approximately 10 times higher than that of nitrates: a lethal dose for humans is 2–4 g and 10–15 g, respectively.

Poisoning most often occurs when consuming agricultural products that exceed the permissible level of nitrates.

Such vegetables and melons can often be identified without measuring the level of harmful substances with special equipment, by their appearance. The risk of acute intoxication is especially high when consuming products with the following symptoms:

• cucumbers saturated with nitrates do not have a light grassy shade of the peel, but dark green;
• cut tomatoes are of uneven color, pink-red flesh is interspersed with dense light areas and veins, the peel around the stalk is light yellow or greenish;
• unnaturally bright color of greens (parsley, dill, lettuce);
• excessively large size (potatoes, beets) and the green upper part bordering the tops of root vegetables (radish, carrots);
• dark green skin around the stalk of the zucchini.

Poisoning of a breastfed baby is possible if the mother consumes foods high in nitrates, since nitric acid salts penetrate well into breast milk.

Symptoms of poisoning

Once in the gastrointestinal tract, nitrates are quickly absorbed into the systemic circulation. Upon contact with the respiratory protein hemoglobin, nitrites formed during the nitrate reduction reaction change the iron atom in hemoglobin and convert it into methemoglobin. The resulting substance is not able to bind and transport oxygen, which leads to a decrease in the oxygen capacity of the blood and the development of hypoxia of organs and tissues.

The destruction of methemoglobin occurs under the influence of an enzyme, the production of which begins at three months of age, so children in the first year of life are especially vulnerable to nitrates.

Against the background of tissue hypoxia, a number of systems and organs are involved in the pathological process, which causes the development of characteristic signs of acute nitrate intoxication. Symptoms of poisoning appear 1–6 hours after consuming high-nitrate foods:

• nausea, vomiting;
• loose stools;
• pain and heaviness in the right hypochondrium due to liver enlargement;
• decreased blood pressure;
• frequent arrhythmic thread-like pulse;
• coldness and cyanosis of the extremities;
• increased breathing;
• noise, ringing in the ears;
• headache, dizziness;
• drowsiness, deterioration in general health;
• in severe cases, loss of consciousness, coma.

With chronic nitrate poisoning, performance decreases, vitamin deficiency develops, metabolic processes and the functioning of organs and systems are disrupted. Victims experience a depressed state, even to the point of developing depression.

Source: depositphotos.com

First aid for nitrate poisoning

In case of acute nitrate poisoning, you must:

• rinse the stomach, for which you need to drink 1–1.5 liters of warm water or a weak solution of potassium permanganate and induce vomiting by pressing on the root of the tongue;
• take enterosorbent (Enterosgel, Polyphepan, Polysorb, Activated Carbon);
• take a saline laxative (Magnesium sulfate) - only if there is no diarrhea;
• organize an enhanced drinking regime to prevent dehydration.

When is medical attention required?

Qualified help is needed if:

• while emergency care is being carried out, the victim’s condition remains stable or worsens;
• neurological symptoms have developed (impaired coordination, vision or speech, seizures);
• there are traces of blood in the vomit or stool;
• symptoms of dehydration have developed (dry mouth, decreased blood pressure, a sharp decrease in urination, urine has become concentrated, with a strong odor);
• vomiting or diarrhea becomes uncontrollable;
• a child, an elderly person or a pregnant woman was injured.

In this case, treatment of nitrate poisoning is carried out in a hospital setting. Detoxification therapy, measures aimed at maintaining the function of vital organs, and symptomatic treatment are carried out.

Possible consequences

The consequences of nitrate poisoning can be:

• reactive inflammation of the pancreas, organs of the hepatobiliary zone;
• development of allergic reactions;
• exacerbation of chronic inflammatory processes;
• water-electrolyte imbalance;
• violation of all types of metabolism.

The main danger of chronic intoxication with nitrates is that the nitrites reduced from them combine with the amines and amides of any protein products and form highly toxic nitrosamines and nitrosamides. These compounds have a pronounced carcinogenic effect, damaging primarily the hematopoietic, lymphoid and digestive systems.

Prevention

To avoid nitrate poisoning, you must:

• limit the consumption of out-of-season vegetables and fruits;
• thoroughly soak, wash and peel vegetables before eating;
• peel the skins of vegetables, as this is where the maximum concentration of nitrates accumulates;
• before use, cut off the top part of root vegetables (carrots, beets) at a distance of 1-2 cm from the tops;
• do not eat the pulp of melon and watermelon in close proximity to the peel;
• defrost vegetables immediately before cooking;
• When cooking and stewing zucchini, beets and cabbage, do not cover with a lid;
• Use freshly prepared vegetable juices immediately or sterilize them.

Video from YouTube on the topic of the article:

But if nature provides for a small dose of nitrates in plant products, then greenhouse farms add them to fertilizers, exceeding the norm several times. As a result, every buyer of such “healthy food” becomes a victim of poisoning.

Nitrates - what is it?

Salts of nitric acid, which are essentially nitrates, are used in many fields: in medicine (for the production of drugs), pyrotechnics and even astronautics (for the creation of rocket fuel). The most common sector of their application is agriculture. Farmers have long and successfully added nitrates to fertilizers to make vegetables and fruits ripe in the off-season, as well as to make them more beautiful and juicy.

If the dose of the substance is exceeded, immediately after entering the body, nitrates are quickly absorbed, turning into poison. This happens as follows: nitric acid interacts in the blood with oxyhemoglobin (the main source of oxygen for the body), resulting in the formation of methemoglobin. It, unlike oxyhemoglobin, is not capable of transporting oxygen to tissues. For this reason, the body experiences oxygen starvation.

For the first symptoms of nitrate poisoning to appear, 15% of methemoglobin in the blood is enough. At 50% a person can die from suffocation (usually 8-14g of nitrates or 1-4g of nitrites).

Nitrate poisoning. How do you know if vegetables are dangerous?

Products with excess nitrates have a specific unnatural taste.

They also differ from others in size and juiciness - it is better not to buy giant watermelons or plums.

Sometimes cracks in vegetables and fruits indicate a high concentration. Moreover, upon contact with air, nitrates turn into nitrites for a few minutes - substances that are even more dangerous to health.

Vegetables or fruits with nitrates are not capable of long-term storage; after a while, inside they turn into a jelly-like liquid.

Nitrate poisoning: which products are at risk?

Most often, a dose of nitrates dangerous to health is found in:

Winter cucumbers and tomatoes

Herbs: dill, parsley, green onions

Watermelons and melons

• Potatoes

The first “bells” from the body in the form of poor health begin to arrive 2-6 hours after nitrates enter the body. Moreover, each patient has his own degree of severity of symptoms. In addition, their severity will depend on the dose of nitrates received, the state of the protective intestinal microflora and individual sensitivity.

In most cases, nitrate poisoning manifests itself:

Nausea, vomiting

Diarrhea (with chocolate-colored blood)

Yellowness of the whites of the eyes

Blue discoloration of lips, mucous membranes, nail bed)

Pain in the right hypochondrium (in the liver area)

Decreased blood pressure, dizziness, weakness

• Drowsiness

  Temperature increase

  Loss of coordination

  Ear headache, noise

  Cyanosis, tachycardia, shortness of breath

  Loss of consciousness, convulsions (in rare cases)

Nitrate poisoning in children

A child can be poisoned by nitrates, even if he was not given vegetables and fruits the day before - for this, a milk formula prepared with low-quality water, juice made from fruits with nitrates, etc. is enough.

Unlike adults, poisoning in children affects the nervous and circulatory systems. The signs are:

Low activity

Blue lips and nails

• Convulsions, loss of coordination (with severe oxygen deprivation)

But as for such “adult” signs as vomiting or diarrhea, they can be either mild or absent altogether.

Sometimes the clinical picture of nitrate poisoning is similar to toxic manifestations.

First aid for nitrate poisoning

If the patient is not unconscious, try to induce vomiting. To do this, you must first drink a large amount of clean, cold water. As soon as the stomach can be cleared, you can use any medicine from the group of enterosorbents (even suitable).

Remember: you need to drink plenty of fluids to remove nitrates. As soon as the nausea stops, the victim can brew strong black tea with lemon. No alcohol at all! It only exacerbates the toxic effect of nitrates.

After poisoning the patient for some time, it is better for the patient to switch to a regimen that includes:

Vegetable stew

Lean cooked meat

Bread kvass

Salted cucumbers

Sauerkraut

These products help the body recover more quickly after poisoning.

If the patient loses consciousness, and diarrhea and shortness of breath do not go away, call an ambulance.

When hospitalizing a patient, doctors pay the greatest attention to:

Elimination of hypoxia

Hemoglobin restoration

Removing toxins from the body

For this purpose, solutions of ascorbic acid, sodium thiosulfate, or oxygen therapy may be prescribed intravenously. To support the heart and restore tissue respiration, the patient is prescribed.

Chronic nitrate poisoning

In most cases, the body is able to cope with microdoses of nitrates without outside help. But this does not apply to cases of pregnancy: when the cells of the mother’s body desperately need oxygen, this cannot but affect the child.

So far, the exact effect of nitrates on the fetus has not been revealed, since conducting such experiments is inhumane, but animal studies show that long-term use of nitrates ends in miscarriage.

How to avoid nitrate poisoning

Most cases of poisoning occur in two seasons: spring and summer. As soon as it gets warmer outside, but the first fruits are still far from ripening, greenhouse products appear on store shelves. But in the summer the melon crops will gradually ripen. During this period, you should be especially careful when buying fruits and vegetables - they could be grown with nitrates.

Buy watermelons only at certified points of sale, no earlier than in mid-summer (before that they will not ripen without nitrates), try not to give watermelon to small children.

As for vegetables, do not forget to cook them before serving them. This is especially true for carrots, beets and potatoes. But you shouldn’t store it in this form for too long either - there is a high risk of nitrite formation.

Soak greens before eating - this will reduce the risk of poisoning.

Try to drink freshly squeezed juices immediately, so that during storage in the open air, nitrates do not turn into more toxic nitrites.

Remember: most nitrates accumulate near the surface. For example, in cabbage - in the upper leaves, in greens - in the stem, and in watermelons - under the rind, so it is better to get rid of them if possible, especially if the vegetable grew in the off-season.

poisoning , nitrates ,