How to check for nitrates in watermelon. Environmentally friendly watermelons on their own bed

Before the official start of the season, the sale of watermelons remains for about a week, but unauthorized trade of Bakhchev on the streets of Moscow is back from mid-July. Consumer indignation causes not only a high price, but also the quality of fruits: watermelons, which are artificially dose with nitrates, are dangerous to health.

At the same time, sellers of watermelon collaps in most cases cannot impose any permits for trade or quality certificates.

The permission to trade Bakhchev will really be from August 1. In the Department consumer market And Moscow services explained that before this period, buy watermelons is not recommended - it is better to wait until the end of the summer when they exactly ripe.

The number of mudflows in the capital this summer will be almost twice as fewer compared to last year. - Total 450. . In addition, the shopping points will work according to the new rules. Sellers are required to work in special clothing, have a medical book and documents confirming the quality of products with them.

Where to choose watermelons

In Moscow, the sale of Bakhchyeva "from the Earth" is prohibited. Shopping points must be equipped with mesh gaming and special weights instead of household, medical and postal scales. Sellers should not be cut and implement watermelons and melons with parts, in cutting.

In addition, visual information on the mode of operation of the trading point and the legal address of the trade organization should be posted on the tray or collapse.

To protect yourself, it is best not to buy watermelons on "sponsors", where products are not checked by sanitary services, and always ask whether there are documents on them. And even more so do not buy on the collapse of the roads: there are products of toxins.

Maturation of Bakhchyev Some manufacturers are stimulated by nitrogen fertilizers, which leads to cluster in watermelons of nitrates. The consequences of their use may be severe - acute infectious poisoning or chronic intoxication that doctors call the "cumulative effect".

How to determine the nitrate "bomb"

It is impossible to define a nitrate watermelon on the eye if it is not cut. The berry should not even try if the flesh is permeated with yellow or light yellow fibers or has a purple shade.

If we twist the pulp of the nitrate watermelon in water, then it will become red or pink due to the increased content of nitrates. "Healthy" watermelon will make water slightly muddy.

If you knock on a nitrate watermelon - the feeling as if we beat the right ball. On the appearance of such a watermelon can be mature, but if in compression it does not crack, it means that it is not ripe not without someone else's "help"

How should watermelons look like without flaws

There is a common belief that large watermelon is "nitrate". This is not true: for example, for a variety of "chill" 10-20 kilograms - far from the limit.

The perfect watermelon should be large enough, while not very heavy and with a clearly pronounced striped pattern. In order to determine the natural ripeness of the watermelon, first of all you need to pay attention to the fruit - the tail on the top of the fetus should be dry.

The purchased watermelon should not have cuts and cracks - through which the microbes causing intestinal infections fall inside.

There is a myth that ripe watermelon Must ring if it is patoned by palm. In fact, the sound depends on whether it softened inside the flesh or not. Just green fruit and will ring, and ripe watermelon must be deaf.

Crack, which publishes watermelon if it is squeezed with hands, is a good sign. Such a product can be safely bought.

Earth stain down at side, it is desirable, it should be yellow, not white.

And last. Ripe watermelon can be easily scratched - having spent on it, you will easily remove upper layer Peel.

When choosing melon, experts advise to pay attention to the fragrance, which should exude its peel, on the softness that is felt on the touch, as well as on the absence of light brown spots.

What to do in case of "nitrate" poisoning

In addition to nitrates in watermelons may be contained microbes, and even heavy metals. In case of poisoning, it is necessary to drink as much water as possible to prevent dehydration and reduce the manifestations of the disease.

Whether watermelon is useful

There are conflicting information about the benefits of watermelons. Some say that the fiber of watermelons contains potassium, which when taking diuretic drugs is washed out of the body. Therefore, watermelons advise consumes with such diseases such as cystitis and jade.

At the same time, there is an opinion that all bahch culture Although they contain fiber, but it is poorly absorbed, loading the stomach. That is why doctors advise children and older people over 50 years old to abandon juicy fruits.

Material prepared by the Internet version of www.rian.ru based on RIA Novosti information and open sources

You need to choose a watermelon in several signs.

1. The most ripe watermelon weighs 7-8 kg.

2. Strips at ripe watermelon greater constantness than the unreliable.

3. On the side of the watermelon is yellow, and not a white spot.

4. The tail of the watermelon is dry.

5. Sound at ripe watermelon, if you knock down your palm, is a ringing, "bell", and not deaf and low.

It is impossible to buy watermelons from the rooks of the roads and in the places of unauthorized trading.

"First, it is in such places that vegetables and fruits are sold, which have not been certified, including watermelons. Secondly, everyone knows that, being a day near the track, watermelons and other fruits absorb all harmful substanceswhich are then accumulated in the human body. We often ask for a piece of watermelon on a sample. But the crust of watermelon, and the knife is contaminated with bacteria. And please, please intestinal infection! Or, bringing the watermelon home, some immediately cut it onto the slice, and the feast begins. But you just imagine that long way, which watermelon did before getting to your table with Bakhchchi ... What only he did not make it on the way! Therefore, first of all, thoroughly wash the watermelon surface flowing water, better with washcloth"," expert advises.

Sometimes people buy overripe watermelons or do not comply with storage mode, and the berry begins to deteriorate. Such watermelon can also be poisoned. To determine if the watermelon was not overriser, knock on his crust. A deaf knock means inside the fetus there is emptiness - it means he overrered. Shake watermelon. The "Boltanka" inside means the following stage of the perishadled either the enjoyed fetus: the process of dissolving the pulp to the liquid state began. Such watermelon should not buy: it is dangerous.

You can check the watermelon like this:

1. If the watermelon is puzzled by nitrates, its flesh has intensively red color with a small purple tide.

2. In a healthy watermelon, fibers that go from the core to the crust, white, dark white, but in no case are not yellow.

3. A good watermelon is sparkled with grocers, a nitrate is smooth, glossy

4. A piece of puffy watermelon must be confused in a glass with water. If the watermelon is good, the water in 15-20 minutes simply throws. If not, it will become red or pink.

What if they poisoned?

Of all the summer gifts of nature, it is watermelon who is most often the cause of poisoning with nitrates, since his flesh absorbs them, and eat it with huge portions. Therefore, even at a small concentration of nitrates, you can also choose. This is usually manifested by weakness, headache, nausea, vomiting and diarrhea. In this case, it is necessary to rinse the stomach with salted with water or a weak solution of manganese and drink a lot of warm liquid. If weakness increases, the temperature appears, the lubrications in the joints and darkens in the eyes, it is better to call ambulance.

Remember that poisoning is dangerous not only in itself. It can cause aggravation of chronic diseases. Among them is gastritis, ulcer of the stomach, enteritis, colitis, pyelonephritis and many others.

We all care about health and try to buy only quality food. But sometimes the danger is quite difficult to notice. In many vegetables, fruits and berries, an increased content of nitrates is found. What is it dangerous? In itself, nitrates are not dangerous, but when human bodythey enter into chemical reactions and turn into harmful substances.

Watermelons are peculiar to absorption of soil nitrates. It can be dangerous for a person. Today we will talk about how to check the watermelon on nitrates.

Choose the fruits correct

• do not buy berries in the natural markets, next to the roads, where they absorb heavy metals from automotive exhausts that are no less bad than nitrates;
• do not buy chopped, or damaged fruits, because Harmful bacteria existing on the surface of the watermelon can penetrate and pollute the flesh. The chopped berries are very hard to rinse well, and they can act as causative agents of serious intestinal diseases;
• buy watermelons need in places where there are conditions for their sale. The place of sale should be fenced and have a canopy. Berries should not lie on Earth, they must be on special trays.
• it is necessary to familiarize yourself with the papers confirming the quality and safety of the sellable fruits;
• before using the berry in food, it is necessary to clean it thoroughly under running water.

Check the content of nitrates

Of course, the most reliable method of verification is the use of a special device - nitrometer. But such a device is not all, so we will list several more ways to test the watermelon on the content of nitrates at home.

1. You need to grind a piece of fruit pulp in a glass with water. If after 15 minutes the liquid has become a muddy - we can eat the berry if the fluid has become pinkish - in such a watermelon, the permissible number of nitrates is exceeded, and it is not suitable for food. It should be borne in mind that this method is not accurate.
2. It is the opinion that if yellow or light yellow fibers are visible in the meatpiece of watermelon, that is, the probability that there are too many nitrates. Starids can only be white.
3. The next criterion for exceeding the rate of harmful substances is smooth and shiny on the bottom of the cut, a tagging is noticeable on the cut.
4. You can lower the watermelon into the container filled with water. If the fruit good quality, He must emerge.
5. You can try to determine the quality of the watermelon by sound. A good fruit when tapping will publish a ringing sound.
6. The pulp of a good fruit is a sahary, bulky and grainy. Nitrates make it smooth and brilliant.

Impact of nitrates on the human body

Finding into a fat intestine of a person, nitrates turn into nitrites and enter blood. Because of this, the hemoglobin methemoglobin is replaced, which is unable to transmit oxygen, and the organism may begin lack of oxygen. This can cause poisoning with nitrates, and even a fatal outcome.

Signs of rustic poisoning is considered an oppressed state, nausea, vomiting, diarrhea, an increase in the liver. Such poisonings are especially dangerous for children, because their weight is less and they have no enzyme that is capable of converting methemoglobin into hemoglobin. Therefore, it is impossible to offer all small children to offer watermelon.

Under the influence of high temperatures, the nitrates are disintegrated. Also harmful substances in the armelorevillese for the reason that it is eaten without prior processing.

If the product you purchased did not pass the check, and you are worried about its quality, it is better to cut the flesh, which is located in the fruits and up to two cm below the surface of the peel. In these zones, most of the harmful substances are concentrated. The most secure parts of the watermelon is the middle of the fetus.

When buying a watermelon, it is enough to determine the number of nitrates. Therefore, try to concentrate on this issue at home. It is important to realize that such food will not benefit your body, on the contrary, can harm him.

If all of the listed methods of verification indicate the increased content of harmful substances, do not regret money, get rid of such a product.

Eat only high-quality watermelons in food, we hope that our advice will help you with it.

Watermelon is loved by many berries, which combines useful qualities and amazing taste. However, everyone useful characteristics this berry is reduced to no if in the product itself is found a large number of nitrates. Therefore, the choice of good, not spoiled by the dangerous substances of the product is very important. In this article we will tell how to find nitrates in watermelon and how to distinguish a nitrate watermelon from healthy.

Nitrates are substances that are widely used in agriculture, mostly they are contained in fertilizers. Strictly speaking, there are no such products in which they would not be contained at all. In small quantities, they do not pose a danger to a person, however, if the level of their content in the product is high, they pose a threat to the consumer.

In itself, nitrates are not dangerous, however, when they fall into gastrointestinalThey turn into very dangerous nitrite for our body. These are salts of nitric acid, which are able to cause oxygen starvation in the tissues of our body. They are also able to provoke problems with thyroid gland or cause food poisoning (diarrhea can be a direct consequence of product consumption with high levels these substances).

Verification methods

So how to check the watermelon on nitrates? There are several ways to do this. It is possible to carry out a procedure in laboratory conditions, using special equipment, or try to independently determine whether the number of nitrates in the berries of the permissible level does not exceed.

There is a special device called a nitrateometer, with which it is possible to maximize precise definition The level of these substances in the product. However, despite the high efficiency, the price of the question is quite high. Therefore, you can use some folk methodswhich also turn out to be very effective.

To the question "how to check the watermelon on nitrates at home" is responsible in different ways, since there are really many methods. The first one (and the easiest) - place the berry in the water tank. If it pops up, it means that the watermelon is very good and high-quality, but if the fruit drowned - there is a very large number of nitrates.

In addition, high content These substances testifies to the presence of white streaks on the pulp of berries.

Another way to reveal the watermelon with nitrates - cut off the slice from it and put in a plate filled with water. If, after ten minutes, the water began slightly muddy and acquired a pinkish hue - it means everything is in order.

But if she changed the painting on the bright pink (even slightly purple) color - it urgently needs to get rid of the fetus. In addition, we recall that the berry itself needs to be very thoroughly rinsed before use and do not forget that places of cluster of nitrates, as a rule, is a peel. Therefore, with direct use of fruits, it is not worth eating them to the crust itself - it is fraught with unpleasant consequences.

How to choose watermelon

Above, we described ways that will prompt how to determine the high content. toxic substances In the berry, when it is already on your table. However, you can try it to do it before buying, to accurately be sure that you will bring healthy and tasty watermelon.

How to distinguish watermelon quality from poor quality? Signs of healthy fruits are as follows: First, the berry has a dry berry; secondly, the striped pattern, which covers the surface of the watermelon, should be clearly pronounced; Thirdly, a small earthy spot can be discovered on the side of the berry. In addition, the surface of the fetus should be glittered, and there should be no matte plaque on it.

In addition, it is possible to purchase such products only in proven places, on specialized markets or in stores to accurately be sure as berries. First of all, you should pay attention to how they are stored. They must be placed in pure boxes, and not lie on dirty semi. In addition, it is important that the fruits be integer - when buying a cracked or broken fetus you are tangible. Also healthy watermelons differ in that when tapping, you can hear a distinct deaf sound. Ripe fruits achieve rather large size (for their variety, of course), but when weighing are not very heavy.

Do not take too early berries. Until mid-July, the likelihood of nitrate fruits is great. But if you buy them already in mid-August or even in September, you will not even need to worry about the fact that products contain harmful substances. Good sellers You will always be able to provide documents confirming the quality of their goods, so do not hesitate to ask them. In addition, they can always cut off a small piece of watermelon on the sample. A good fetal pulp is a grainy (however, too grainy pulp testifies that the product fell), and when conceded, white fibers can be seen.

If the fibers have a yellowish tint, this indicates that the fruit is most likely nitrate. Normal watermelon has a pink pulp, so if the product is bright red to you, there can be only a few options. Either this is some kind of specific grade from which it is painted in such bright color (in this case, it is better to clarify where such a product was brought), or (and it is much more likely) in the proposed product contains really great amount nitrates. Neither feel free to ask questions to the seller, because your health depends on the quality of their goods.

Video "Check watermelon on nitrates at home"

From this video you will learn how at home check watermelon for nitrates.

You can check the watermelons on the content of nitrates not only in laboratory conditions - there are signs for which even at home is easy to find out if they are in food.

In addition, you should learn to choose a watermelon correctly, because its quality can be defined before purchase. You need to pay attention both to the fetus itself and on the equipment of the trading place (often even good watermelon It can be spoiled, staying in improper conditions). As an example, let's try to choose and check the watermelon on nitrates at home.

Fast navigation on the article

Selection of watermelon

To protect yourself from buying a "harmful" watermelon, you need to pay attention to the following:

• Purchase watermelons follows specialized markets, where appropriate storage conditions (hygienic and sanitary) have been created, and there are special permits;
• Watermelons should not contact the Earth - lie on the floor (in order to avoid dirt in the microcrack). All the fruits are customary to store on special commodity shelves, in pure containers;
• It is better to avoid purchasing a cut, cracked, mint or broken watermelon, since in the sweet pulp of the microbic berries apply particularly quickly (including under the closed films). For the same reason, it is better to abandon the sacred watermelon in the market;
• Ripe and grown in natural conditions (Without unnecessary feeding), watermelon rings when tapping, and it will be dry.

Check for nitrates

There are several ways to check the watermelon at home nitrates:

• Whole watermelon can be omitted into water capacity (for example, in the bathroom). If the watermelon pops up, it means it is high-quality, and if it goes to the bottom - then with nitrates;
• Clearance of pure watermelon will be uneven, with grains. Smooth bright slice indicates a high content of nitrates;
• Large yellowish or white streaks in the flesh - also a sign that watermelon has overlooked fertilizers;
• You can see the section of the watermelon to the light and if the surface is slightly different purple color, such a fruit is better not;
• A piece of watermelon pulp can be lowered into clean water and leave for 15 minutes. If water simply throws away from the pulp - the watermelon is good, and if it is painted in a bright pink or red - it means watermelon with nitrates.

Eating watermelon

It is also necessary to remember the rules for the use of watermelon:

• Watermelon is an independent dish. It is necessary two hours before or two hours after the main reception of food (the combination of watermelon with another food can overload the stomach);
• Before use, watermelon needs to be thoroughly washed out with clean running water;
• Most of all nitrates are preserved in the peel of fruits, so it is not worth eating watermelon to the peel.

Now, people are ready to drink chemistry food to just give them marketable conditionAnd immediately put them on sale.

How to determine nitrates in watermelon, video

But who wants to go to the hospital after eating a favorite fruit or vegetable? For this, it is worth reading articles to distinguish a good watermelon, from watermelon stuffed with chemical additives.

The more colorful and contrasting the watermelon - the better it will be more.

An important indicator of the state of the watermelon is the color of the residences inside the meat of watermelon. If their color is white, then watermelon with confidence can go to your stomach. If the bodies are selected yellow or purple color, that is bad sign - Such watermelon, or not completely matured, or the result of the invasion of the pest, but in most cases it is the impact of nitrates.

Immediately remembered the hippo from "Well, wait for"

But oddly enough, this method works almost always, if there are strength, of course, to compress watermelon.

Check on gloss

Also pay attention to the seeds - they must be mature!

Fresh, snowy, gently crispy

I'll rush, in Aluu sweetness yelling.
This is a miracle, while present -
Our Baskunchaksky, Liman Watermelon!

What a twist

It is usually said that nitrates are small in the middle, but a lot - closer to the peel. As it turned out, it is not always that way.

Water Test

And you can check this way: throw a piece of watermelon meakty into the water, if he drowshes - watermelon is fed by nitrates, and if you can swim - good!

By the way, how to choose the right melon and cook it, read here!

Torn from Bakhchka

When watermelon matures, it is separated from Bakhchch through the fact that his tail dries on its own. If you do not see the tail or it will somehow hide, most likely the seller hides something from you.

The ripeness of the watermelon and the naturalness of its origin can be determined by the earthen stain

At one of the watermelon barrels, there must be a brown-yellow or orange-yellow spot - it was a side of watermelon lay on Earth. But keep in mind that the stain should not be white!

Oh, this sound

The sound of the watermelon depends on whether it softened inside the flesh or not. Just green fruit and will ring, and ripe watermelon will make a deaf sound.

Checking how the bees worked on the watermelon

These mesh appear because the bees hide the marking during pollination, respectively, the more often pollination occurred, the fetus will be sweeter.

Turn the skin to the density

When the watermelon matures and separated from Bakhchchi, it is no longer able to absorb water, because his crust solidifies. If you can easily pierce the peel of the nail, you are immature fruit.

Girl or boy?

Watermelon - Berry Two: "Male" Special is more elongated, has a convex bottom and a small circle, "female" berries - a wider circle. "Girls" are considered tastier: they have less bones, and sugars are more.

If you still hit a nitrate watermelon, then you will be disturbed by the following symptoms

2-6 hours after the eating of the watermelon:

• nausea, less often vomiting;
• diarrhea (up to 10-15 times a day);
• abdominal pain, spasms;
• weakness;
• dizziness, headaches;
• temperature increase.

What to do with watermelon poisoning:

1. Rinse the stomach large quantity Warm, salted water or a weak-pink solution of manganese.
2. Accept enterosorbents - medicationsneutralizing poisons in the intestinal lumen. The most popular: activated carbon, "Polysorb MP", "Enterosgel", "Smekt".
3. Drink as much liquid as possible to strengthen the elimination of poisons from the body, as well as prevent dehydration.
4. Drink sweet tea with lemon after stopping nausea.
5. Do not take antiquia and painkillers, they mask the true state of the body.

If within two hours your condition does not improve - you should consult a doctor or call an ambulance!

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How to identify nitrates in watermelon?

Nitrates and nitrites:
Methodology Definition
in agricultural
Product

Research work in chemistry and ecology

Recently, scientific societies are being created in many schools, in which students join research work. No exception and our school. In the last school year, with my student I submitted to the court to the competent jury, consisting of researchers of the Khingan State Reserve, this work to the regional scientific and practical conference. Of the 24 competitive works, 6 (including our) were recognized as winners.
The proposed material can be used as a lecture accompanied by a demonstration experiment (or laboratory experiments, at the discretion of the teacher) when studying the topic "Nitrate" in the 9th grade.

Purpose of work. To study the literature on nitrates and nitriets, master the methodology for their determination, determine the content of nitrates and nitrites in agricultural products purchased in the store and grown on its own garden plot.
Perspective goals. Determine the presence of nitrates and nitrites in greenery, vegetables and fruits grown in the fields of the area. Check compliance with the norms of the amount of nitrogen fertilizers.

Lesson plan

The problem of nitrates and nitrites.
Nitrosamines.
The quality of vegetables and conditions for their cultivation.
Determination of nitrates in plants.
Determination of nitrites in plants.

The problem of nitrates and nitrites

The problem of nitrates is actively discussed by the public from our country. Let's try to figure it out in this matter and we.
Nitrates - nitric acid salts, for example Nano3, KNO3, NH4 NO3,
Mg (NO3) 2. They are normal products for the exchange of nitrogenous substances of any living organism - vegetable and animal, so no "neglected" products in nature does not happen. Even in the body of a person per day is formed and is used in metabolic processes of 100mg and more nitrates. From nitrates, daily adult people entering the body, 70% comes with vegetables, 20% with water and 6% with meat and canned products.
But why do they talk about the dangers of nitrates? When consumed in elevated amounts, nitrates in the digestive tract are partially restored to nitrites (more toxic compounds), and the latter can cause methamoglobinemia during admission to blood. In addition, n-nitrosynins with carcinogenic activity can be formed from nitrites in the presence of amines (contribute to the formation of cancer tumors). When taking high doses of nitrates with drinking water or 4-6 h products appear nausea, shortness of breath, formation of skin and mucous membranes, diarrhea. All this is accompanied by a common weakness, dizziness, pain in the occipital region, heartbeat. First aid - abundant stomach wash, reception activated coal, salt laxatives, fresh air. What is the safe share of nitrates?
The permissible daily dose of nitrates for an adult is 325 mg per day. As you know, in drinking water The presence of nitrates to 45 mg / l is allowed. Recommended food intake, which uses drinking water (tea, first and third dishes), approximately 1.0-1.5 liters, maximum - 2.0 liters per day. Thus, with water, an adult can consume about 68 mg of nitrates. Consequently, 257 mg of nitrates remains for food.
Studies have shown that the toxic effect of food nitrates is weaker than those contained in drinking water, approximately 1.25 times. In fact, safely with food products consume 320 mg of nitrates per day.
For vegetables and fruits, the following values \u200b\u200bof maximum permissible concentrations of nitrates are installed (Table 1).

Table 1

Maximum permissible concentrations of nitrates
in crop products

What are the main sources of food nitrates? Almost this is extremely vegetable products. In animal products (meat, milk), the content of nitrates is very slightly. The maximum accumulation of nitrates occurs during the period of the greatest activity of plants in the ripening of fruits. Most often, the maximum content of nitrates in plants is before the origin of harvest. Therefore, unripe vegetables (zucchini, eggplants) and potatoes, as well as vegetables early ripening May contain nitrates more than those who have reached normal cleaning maturity. In addition, the content of nitrates in vegetables can dramatically increase with improper use of nitrogenous fertilizers (not only mineral, but also organic). For example, when making them shortly before harvesting.

Vegetables - Nitrate sources

We talked about the overall pattern of accumulation of nitrates. However, U. various plants There are their individual features. Known "drives" of nitrates. These include green vegetables: salad, rhubarb, parsley, spinach, sorrel, which can accumulate up to 200-300 mg of nitrates in 100 g of greenery. Beets can accumulate up to 140 mg of nitrates (this is an extremely permissible concentration), and some varieties and more. But in other vegetables nitrates are significantly less. Fruits, berries and mesh contain nitrates are very small (less than 10 mg per 100 g of the fetus).
In plants, nitrates are unevenly distributed. In the cabbage, for example, nitrates accumulate most of all in the norake, in cucumbers and radish - in the surface layers, in carrots - on the contrary. On average, 10-15% of nitrates are lost during washing and stripping of vegetables and potatoes. Even more - with thermal culinary processing, especially when cooking, when it is lost from 40% (beet) to 70% (cabbage, carrots) or 80% (potatoes) of nitrates. Since nitrates are chemically quite active compounds, then when storing vegetables, their content decreases in a few months by 30-50%.
Now that everything is known about food nitrates, let's try to present their real health hazard. Consider the main sources of nitrates. Let's start with green vegetables (salad, parsley, dill, etc.). Their consumption practically rarely exceeds 100 g per day, and most often about 50 g, i.e. One portion can be obtained less than a third of a safe daily dose. (Above noted that, taking into account the bioequivalent, the safe share of nitrates in food products It is about 320 mg.) We now move to the beet. It is known to consume only in boiled form. Since under cooking (40%) and stripping (10%) is lost half of nitrates, and catering Recommends the portion of boiled beets in 125 g, then with beets we can get 100 mg of nitrates (less than a third of a daily dose). Potatoes and cabbage in boiled form are consumed by portions of 300 g. Taking into account losses at stripping and culinary processing with one portion of these products, we can consume about 60 mg of nitrates.
Similar calculations were made by other vegetables and other culinary treatments. It turns out that with the usual rational consumption of vegetables in a fresh form or culinary formation, we will almost never be able to exceed the safe daily dose of nitrates. Moreover, in accordance with the recommendations on rational nutrition, it is not necessary to constantly eat alone and the same products, such as potatoes or cabbage.
Indeed, if you contact the recommended rational average daily set of products, then potatoes should be consumed 265 g (based on the purchase of a product), vegetables and bachcheva - 450 g (including 100 g of cabbage). Such a diet can give us a maximum of 200 mg of nitrates. Practically, as shown by calculations, the average daily consumption of nitrates with basic roots, vegetables, mesh and fruit, taking into account these actual nutrition and the actual content of nitrates in food does not exceed 100 mg. At the same time, about a third of nitrates falls with beets, slightly less - with cabbage and potatoes. For other vegetables and fruits - less than 10%. If you break the principles of rational food, for example, feed on one vegetables, and even raw (as they recommend some fans of vegetarianism and raw foods, eat up to 1.5 kg of raw vegetables per day), then it is really possible to exceed the safe dose of nitrates almost twice (more than 650 mg per day), on what we pay attention.
For additional safety, it is noterable to recall the second principle of rational nutrition, which provides for the need for a diversity of food.

Important information: how to determine the nitrate watermelon

Therefore, we do not recommend consuming constantly, and three more times a day, on a snack one and the same vegetable. It should not limit the use of vegetables and fruits in nutrition due to the danger of nitrate poisoning, it will not deprive us of the necessary vitamins. The content of nitrates is now installed strict control in places of production of vegetables and on trading bases.

Nitrosomines

It has already been mentioned that nitrates under some conditions can be recovered in nitrites. In the acidic medium, nitrite gives nitrogenic acid, and it, interacting with secondary and tertiary amines, forms carcinogenic nitrosmen:

Depending on the nature of the radical, very varied nitrosamines may form, more than 100 compounds have carcinogenic effects. Most often in food products, nitrosodimethylamine and nitrosodiethylamine are found. Most of all nitrozamines are found in smoked meat products, sausages prepared with the addition of nitrites - to 80mkg / kg, in salt and smoked fish - up to 110 μg / kg. (IN fresh meat And nitrosamine fish are not found or are in trace amounts - less than 1 μg / kg.) Milk products are found mainly in the cheaps that have passed the fermentation phase (up to 10 μg / kg).

From vegetable products, nitrosomins are found mainly in salt-marinated products, and from beverages - in beer, where the total content can reach 12 μg / l.

Nitrosmen meet in smoked fish and in beer

The quality of vegetables and conditions for their cultivation

The quality of vegetables depends on many reasons, including from the applied fertilizers and used plant protection products.
Nitrates are used as fertilizers and are known as nitrates: sodium (Chilean), potassium (real), ammonia (ammonium) and calcium (Norwegian). Nitrates - the most important component plant food because nitrogen included in them - the main construction material Cells.
The ability to accumulate nitrates different cultures Nonodynakova. The greatest accumulation is celebrated in green crops: dill, parsley, green onions (from 400 to 2500 mg / kg). Tomatoes (10-190 mg / kg), sweet pepper (40-330 mg / kg), eggplants (80-270 mg / kg) have a significantly less ability to accumulate nitrates.
To obtain low-level vegetables, it is necessary to correctly use the alternation of crops in crop rotation, watering and optimal sowing or landing, rationally apply fertilizers. It is known that tomatoes, peppers and eggplants are distinguished by low accumulation of nitrate nitrogen in the fruits, but there are significant varieties in this and the conditions are of particular influence, primarily illumination. Therefore, thickening of crops crops increases the risk of accumulation of nitrates. For the same reason, the content of nitrates in greenhouse vegetables.
An important role is played by the form of applied nitrogen fertilizers and the timing of their introduction. Maximum amount Nitrates in vegetable products accumulates when applying ammonia and sodium nitrate, and minimal - with urea, ammonium sulfate and urea-formaldehyde fertilizer. Under the vegetables, the dose of nitrogen introduced should not exceed 20 g / m2. Conducting acidic soils contributes to a decrease in the content of nitrates in the soil for the four subsequent years. Mineral fertilizers are better to make together with organic in optimal ratios, not forgetting about trace elements.
Nitrogen feeders are stopped 1.5 months before harvesting (after July 10-15, it is better not to contribute).
The accumulation of nitrates in vegetable products is influenced by the humidity of the soil. More moderate nitrogen nutrition of plants is observed in irrigation mode at the level of 80-90% of the greatest humidity.
Pesticides need to be used with caution, because Together with nitrates, they can create an additional adverse background. The varieties of plants should be selected, in the smallest degree of accumulating nitrates, regularly destroy weeds, loosen the soil, widely use biological means Plant protection.
Compliance with the listed conditions will increase the harvest of vegetables and improve their quality.

Definition of nitrates in plants

On the subject glass put several sections of a particular part of the plant. Then, on each slice of one drop of 1% of the diphenylamin solution and monitor the appearance of blue color. The intensity of this color is compared to the table. 2 and with a color scale showing the degree of needy of plants in nitrogen fertilizers. The content of nitrates is reduced with the age of plants, and they almost disappear to flowering.

table 2

Scale needs of plants
in nitrogen fertilizers

Pale blue coloring of the cut from diphenylamine testifies to the acute need of a plant in nitrate ions. Blue color Speaks about the lack of nitrogen in the plant, and the dark purple - that the plant is provided with nitrogen.

Determination of nitrites in plants

Equipment and reagents.Blade, pipette, diphenylamine (crystalline), sulfuric acid (conc.), Strepsid solution (Tablet 0.5g dissolve in 50 ml of pharmacy hydrochloric acid), antipyrin solution (one tablet dissolve in 50 ml of pharmacy hydrochloric acid).
As a result of the participation of enzymes and carbohydrates in plants, the nitrates are restored to ammonia through nitrites:

The forming ammonia interacts with organic acids, as a result, amino acids are obtained:

NH3 + organic acid amino acid.

However, the excess number of nitrates is not restored and, falling into the human body, has an adverse effect on it. When a person gets into the gastrointestinal tract, nitrates turn into nitrites, which cause organism poisoning: dizziness appears, efficiency decreases, the content of the blood of lactic acid, cholesterol, proteins increases, is blocked by hemoglobin, because Nitrites can enter into interaction with it, forming methemoglobin. As a result, tissue breathing is disturbed. With large doses, "blue" develops and death comes.

Progress

To carry out a high-quality sample to the presence of nitrites in plants, several diphenylamine crystals are applied to the surface of fresh cut and wet their two drops of concentrated sulfuric acid. Intensive blue cutting staining indicates a large number of nitrites, pink - on their small content and absence of staining - on the absence of nitrites or on very insignificant content.
To determine nitrites and nitrates, you can use affordable pharmacies: anti-epiрини (pyramidone) and streptocide, which performed the function of the reducing agent, while characteristic coloring appears.
For the study, vegetables grown on their own land plot And purchased in the store. It was found that tomatoes, bananas, pears and cucumbers do not contain nitrates and nitrites. Peaches, cabbage, radishes, peppers, apples contained a small amount of nitrites. And eggplants, carrots and oranges contained a very large number of nitrites. So, to use them is undesirable. What to do if excess nitrites are present in production?
Greens - Parsley, Dill, Salad and Other - you need to put like a bouquet, into the water on a straight sunlight. In such conditions, nitrates in the leaves for 2-3 hours are completely recycled and then practical are not detected. After that, the greens can be eaten in food without fears. Beets, zucchini, cabbage, pumpkin and other vegetables before cooking must be cut into small cubes and pour 2-3 times with warm water, withstanding 5-10 minutes. Nitrates are well soluble in water, especially warm and washed out of vegetables. Ward vegetables reduces the content of nitrates by 50 and even 80%. Care, pickling, marination also reduce the content of nitrates in vegetables. But the drying, the preparation of juices and puree, on the contrary, increase the concentration of nitrates.
The ownership of information about the accumulation of nitrates in plants and on the transformation of nitrates in nitrites and N-nitrosamines will help you to eat and maintain your health.

REFERENCES

Bandman A.L., Volkova N.V. and others. Harmful chemical substances. Inorganic compounds of elements of V-VIII groups. Reference edition. Ed. V.A. Filova et al. L.: Chemistry, 1989, 592 s.; Dorofeyev T.I. These two-year nitrates. Chemistry at school, 2002, No. 5, p. 45;
Melnichenko G.F., Kirsanova V.F., Bitkov N.P. Cultivation of environmentally friendly vegetable products: tomatoes, peppers, eggplants. Blagoveshchensk, 1993, 62 p.;
Skurikhin I.M., Nechaev A.P. All about food in terms of chemist. M.: Higher School, 1991, 288 p.;
Shtovova E.P. Experiments in chemistry with ecological orientation. Blagoveshchensk, 1993, 27 p.