External signs of the presence of nitrates in watermelon. How to check the watermelon on nitrates at home: how not to make a mistake with the choice. What is nitrates and what they are dangerous for a person

Juicy watermelons not every gardener can grow. Therefore, to enjoy such large fragrant berries, we buy them. And coming home, we think that they do not contain surprises unpleasant for us and how to check watermelons for nitrates at home?

Previously, twenty years ago, lovers of Bakhchyev waited for the end of the summer, and today they appear at the end of May. And each of us understands that without "chemistry" there was no reason. But they are so appetizing and so beautifully lying ...

What you need to know if a strong desire to buy watermelons appeared.

What is nitrates and what are they dangerous for a person?

It is impossible to completely get rid of harmful compounds in cultures, because the nitric acid salts are always located in the soil. The plant also has such a property, how to absorb it over the norm for growth, further maturation. Concentrated surplus, transforming into nitrates, becomes harmful, unsafe, negatively affecting human health:

oxygen is bad in the cells, and they are starving

obligations occur in metabolism

becomes a weak immune system

breathing is broken, heart, vessels, gasts

the body is not able to absorb useful substances.

nervous system works unstable

But the body permissible norm is able to display himself. For an adult in watermelon, there is a norm - sixty milligrams per kilogram of weight. For children, it should not exceed fifty milligrams per kilogram of the fetus. The size daily norm For an adult - two hundred milligrams, for children - eighty.

If you use the product with a harmful excess one, you can get poisoning in acute form.

Orientation for the season

Nature has been established so that watermelons before the end of the summer season can not appear. But they have long been on the shelves, it means that special growth stimulants and other additives have been used in their cultivation. Even observe the purchase time, this is also not a guarantee that nitrates are lacking in these watermelons. Security guarantee can only give a crop from their own site.

You can still trust the well-known specialized agrofirms, which are controlled by the relevant authorities, and the quality of their products confirm the certificates. You can buy a "environmentally friendly product" dacniknikov, but today they are such enterprising. Buy watermelons are unknown where, and then resell it seems like from their garden.

Still relevant and operates in our guest time, although he adopted more than thirty years ago. On it in places of sale should not be watermelons of the universal view (fired and incorrect form). In such a place, it is impossible to buy. So how to choose a ripe watermelon?

And the presence of nitrates can be seen when inspection. After all, on the counter, the product must be located face, that is, the watermelon is cut. Let the seller say that summer is hot, the weather conditions are suitable, the product is clean and when growing chemicals Did not contributed. Do not give in!

Do not hurry, you should look at buying. There are signs for which you can determine how convenience is safe:

no traces of strikes, mechanical damage, dents, cracks through which can penetrate harmful chemicals

size - you should not be treated with enormous fruits, and believe the seller who argues that there are such grained giants. Large size corresponds to excessive fertilizer standards, which entails a large content of nitrates. It is better to choose a watermelon of medium size, approximately from seven to ten kilograms, because small, as for evil, will be unricking

present on the peel, ground spots yellow color should exceed ten centimeters, black and brown spots point to super-containers of salts

there should be a dry tail, the place where it grows, also dried and yellow bones pale, immature, shrouded with mucus, in the pulp, which seems ripe, indicate that the growth of the fetus stimulated unnatural

the pulp should be smooth color, matte, with prominent grains. The presence of harmful substances says the hollow pulp in the center, with a shade orange colorand consistency too loose

whole fibers, tough, bodies yellowish should be alert.

And it can all be noticed visually and without any devices. Only the nithenther is a regular guarantee - a personal meter that tests any product for the content of nitrates in a few seconds.

Nowadays, buying a nitrometer will necessarily justify, because they can be checked not only a large red berry, but also other vegetables, fruits, juices, etc. But at home, on their own, how to check whether there are nitrates on a watermelon?

Experts advise crushed watermelon flesh in the glass and pour water. If the liquid simply climbed, it says about normal quantities. If she was painted in pink and even in red, then hazardous substances Here is plenty.

Some check the availability of chemicals with watermelon bathing. In any capacity, water is recruited, it is also plunged. Ripened, just floats on top, and with the power it will have to say goodbye.

You can use special test strips indicator that lay on a slice of watermelon. When they are completely wedged, in two or three minutes the color will be set. It will indicate nitrates.

Their number is determined by the appropriate colors invested. Lovers bakhchy culture It is important to know that nitrates with long-term lying fruit and under the influence of thermal treatment are destroyed. But watermelon is not exposed to high-temperature processing, and consumes it a lot. So, we check the watermelon by all possible methods - or instrument or eye. We also prohibit children, eat the pulp near the crust, because it is there it contains many harmful substances.

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August and September are always associated with watermelons. But to buy ripe, sweet and watermelon grown in natural conditions, you should be guided by several tricks. For example, grab the roulette with you to the store and measure the fruit, then you are not mistaken with the choice. And before serving to the table, drop a piece of meakty in clean water Room temperature to avoid trouble.

We are in website Very love sweet watermelons. Therefore, so that you never mistaken when choosing berries, we have collected for you useful advice From Internet users and added a bonus, in which we will tell about how to choose a truly delicious and ripe watermelon.

1. Yellow crust - a sign of high concentration of nitrates

Nitrogen is an element important to the growth and development of plants. Bakhchevodov, applying it with exceeding the permissible norms, is obtained for 3 weeks the fruit weighing up to 10 kg. The buyer can poison after the use of such a fetus. Therefore, pay attention to the color of the peel when concing the watermelon: it should not be yellow. And in the pulp of good watermelon there can not be white streaks.

2. Make sure that there are no pass-through holes in watermelon

Although someone believes that the holes through - these are traces of insects, and not from nitrate needles, still try not to take such watermelon. Even if the berry is good, some of the pulp will be spoiled.

3. Do not eat watermelon with a big cavity inside

The pulp tears say that the fruit fell or contains growth hormones. Little watermelon can be slightly impressed, and watermelon with growth hormone - cause poisoning. Therefore, such berries are better not.

4. Before there is a watermelon, lower the pulp into the water

To check the watermelon on the content of nitrates and avoid poisoning, lower a piece of pulp into clean water of room temperature. If the berry is dangerous, water will turn into a saturated pink color. This is better not enough.

5. Watermelon should not be easy when you take it in hand

Sometimes even a beautiful smooth peel, a yellow spot and a dry tail do not serve as a guarantee that watermelon is delicious. Be sure to weigh it before buying: it should be dense and heavy. If there are no weights in the store, trust the feelings. Ripe berry should be sufficiently weighty when you take it into hand.

Bonus: how to choose a delicious watermelon

1. Choose the fruit without dents

Ripe and sweet watermelon should be brilliant, even without visible damage. Small dents can be a consequence of bruises. In such places, the damage process occurs faster, there is a chance to throw away most of the fetus in the trash can.

2. holes and shallow holes in the peel fear is not worth

Many Internet users write that these recesses are traces from the needle of Bakhchevodov, which are planted with watermelons with nitrates. If the deepening of non-cuts, they should not be afraid of them: these are traces left by wire larvae. They do not affect the quality and taste of berries.

3. When you choose watermelon, look for small beige traces on the peel

Such beige "scars" on the smooth peel of watermelon is places where the bees tried to "try" the flesh. Internet users checked and decided that such a watermelon is often very sweet.

Very loved watermelons, so often we buy first fruits on the market. But last summer the purchase ended in serious poisoning. Tell me how to identify nitrates in watermelon to protect yourself from repetition of the situation this year?

Watermelon is one of the most favorite delicacies, both adults and children. The striped giant berry is not only delicious, but also very useful for the body. Watermelon is not for nothing.

However, with the beginning of the season of vegetables and berries, consumers lies the danger of acquiring low-quality products. The fact is that in order to obtain earlier harvest, manufacturers almost all cultures are fed by nitrates. For the sake of great profits, quite often the permitted number of nitrates is exceeded at times. Watermelon, "stitched" by them becomes dangerous to health and causes food poisoning. Therefore, it is so important not to buy the first early fruits and berries, especially children.

How to identify an increased amount to protect your family from unwanted consequences? The most accurate will be the use of laboratory methods or a special apparatus - nitrometer, but it is not too acceptable at home. First of all, you should choose the best berries when buying and carefully examine them.

How to choose high-quality watermelon?

Watermelon should be sent to specialized vegetable rows. Unlike spontaneous markets, sellers have in stock documents for selling sales and storage conditions are observed.

When choosing a berry, you must pay attention to the following points:

the fruit should be whole, without traces of damage to the peel;
to the touch watermelon from all sides - solid, without soft, rotting, plots, slightly grungy, but not smooth;
the fruit of ripe watermelon is dry, and the fruit itself rings when they hit;
an earthen spot on the side, which watermelon concerned the soil, has a smooth yellow color.

Home Methods for determining the presence of nitrates

You can independently determine nitrates in watermelons using conventional water. There are two options for checking:

Pour water into a large container and lower the whole watermelon in it. "Drowning" the fruit testifies to a large number of nitrates, and the pop-up can be consumed without any concerns.
Cut off the slice of watermelon pulp and place it in a semoligular jar with water. The liquid should be slightly painted in pink or poisoned. Saturated pink, red or purple water color confirms the presence of nitrates.

Most nitrates accumulates the peel of the watermelon, so it should be cut off to pink pulp.

Sometimes checking the safety of berries can be literally on the eyes. In the rebounded nitrates of watermelon in the context, the bodies of yellow color are visible instead of white, and the flesh itself has an unnatural red. In addition, the pebus peel is perfectly smooth and glitters. Acquire such a watermelon, and even more so it is impossible to use it.

Watermelon Checking for Nitrates - Video

Watermelon is a gigantic berry, to enjoy which they love both children and adults. In addition to taste quality, It is also very useful, it is often used for diets, it also helps well when cleaning the kidneys and the output of slags. With all the utility of this berry, it is worthwhile to fear nitrates that many manufacturers are added to watermelons. What to do in such a situation? How to check watermelon on nitrates at home?

Let's try to figure out how to learn to determine useful berry From harmful and what to do, if the watermelon is already buried with nitrates?

How to check watermelon on nitrates at home: General information

As we mentioned above, watermelons are very tasty and useful productBut it's not all to grow them on your own. The thing is that this fruit has an extremely unpleasant ability - the accumulation of nitrates. So, in case of exceeding the norm, they may cause disorder of the digestive system and poisoning. If they are regularly in the body, it is fraught with the formation of nitrites that can cause more serious health problems.

The greatest danger towes lovers of this dessert with the beginning of the season. The reason lies in the fact that manufacturers in order to get an early harvest as soon as possible, almost all cultures are fed by nitrates. The situation is aggravated by many of them, in order to get maximum profit, can not stop and exceed the pervolored norm of nitrates several times. So, watermelon, in which "stuffed up" so many chemicals, turns from delicious delicacy into a dangerous product that threatens your health, primarily the digestive system.

Important! Do not purchase the first early berries and fruits, as they represent the maximum health danger. In particular, this applies to children.

In connection with the emergence of such a problem, such a question becomes relevant: how to test the watermelon on nitrates at home, so that in order to protect yourself and their loved ones from bad consequences?

Of course, the best and most accurate option for determining the number of nitrates in the berry will be the use of laboratory techniques or a special device - nitratera. However, not everyone has at their disposal this device. Therefore, when choosing a fetus when buying, first of all, it should be pretty inspecting and explore it.

You can actually make such an inspection without laboratory conditions or special devices, there are signs that will allow you to make a qualitative assessment on the suitability of this berry in food and at home.

In addition, it is necessary to learn to choose a berrody correctly, since its quality can be easily identified before purchase. To do this, take a look at the watermelon itself and equipping shopping place (It often happens that even high-quality fruit can be spoiled because of the conditions are not good for its storage).

How to check the watermelon on nitrates at home: how not to be mistaken with the choice?

Nitrates have a property perfectly dissolved in water, most often applied to fertilize plants. Not everyone knows that each product originally contains a certain number of nitrates. But their number is not critical at all and they do not represent any serious danger to human health.

Nutrates themselves do not carry a serious threat, however, when they fall into gastrointestinalIt begins the process of turning into nitrites, which, in turn, have strong toxicity for the body and lead to oxygen starvation of tissues.

Nitrates when human body They can reduce the number of vitamins in food entering the body and disrupt the work of the thyroid gland. In case of exceeding the daily rate of nitrates, the man threatens the stomach disorder, the formation of the skin, heavy breathing, diarrhea and other bad signs of poisoning.

So, how to determine whether you offer watermelon better before you buy? Look, in what conditions are the fruits are stored, are they neatly stored in clean containers? Trace so that watermelons did not lie on the floorAnd they did not get dirt. No need to risk and acquire cracked, broken or crumpled fruit. The seized watermelon, which grew up in a natural environment, will have a dry-haired tip, and if they knock on it, will issue a characteristic ringing. It is not desirable if the berries when examining its cut, the surface will be blown violet tint.

Follow the season and do not buy first watermelons. An experienced buyer always understands at what point you need to abandon the acquisition. Watermelons with na large quantity Nitrates often can be bought in the first half of July. If you get fruit, starting from the second half of August and later, you can no longer be afraid that the number of "chemistry" in them exceeds the permissible norm, most often they are simply not there.

Most sellers enable their customers to taste a small piece immediately before purchasing. In the supermarket in order to show the fruit from the inside, it practices cut it into two parts, after which it turns into a thin food film, through which you can easily see any flaw. However, the visual inspection does not make it possible to determine the presence of "chemistry" in the berry.

The most accurate information on the number of unnecessary substances in the berry can be obtained thanks to the special device - nithertomer. But, unfortunately, this device is not cheap, and not everyone can afford it. Therefore, in this case, it is better to take advantage of folk signs.

How to check watermelon on nitrates at home: Seld tips

There are several options for checking the fetus at home:

1) Watermelon is completely descended into the container filled with water (for example, in the bathroom). If the fruit starts to pop up - it is not necessary to doubt it if it goes to the bottom - it is better to give up use, because it is full of nitrates;

2) In the pure fruit on the cut will be irregularities, grains. If the slice is perfectly smooth and bright - such a fruit is unsafe, especially for children;

3) the presence of large streams in the pulp of a yellowish or whitish shade is bright sign availability of chemicals;

4) Examine a cut in the light - if its surface is somewhat overflowing with a purple tint - it is better not to eat it;

5) Take a piece of pulp, lower it into clean water and leave for 15-20 minutes. If the water begins to curly - the fruit is high-quality, if it starts to paint in a bright pink or reddish color - it is full of chemical fertilizers.

How to check watermelon on nitrates at home: how to use a berry?

Do not forget about the simplest rules of use of this delicacy:

watermelon can be considered a completely independent dish. It is better to eat it 1-2 hours before meals (no need to combine watermelon with other foods to avoid the overload of the stomach);
before drinking the fruit, do not forget to rinse it well under running water;
the maximum number of nitrates is stored in the berry peel, so it is not necessary to eat it to the crust itself.
In the event that you still caught the fruit with nitrates and you buried it, in a few hours you should expect such symptoms:
nausea, in rare cases of vomiting;
diarrhea;
colic, spasms in the stomach;
general malaise;
hurts or spin the head;
increases temperature.

What to do if you feel that they poisoned watermelon:

1) First of all, it is necessary to wash the stomach with the maximum amount of warm water with a pink solution of manganese;

2) Take enterosorbents - preparations that contribute to neutralization of poisons into the intestines. These include: Activated coal, "Enterosgel", "Smekt" and others;

3) Use the maximum amount of fluid - this will accelerate the withdrawal of unnecessary substances from the body and reduce the risks of dehydration;

4) Drink sweet tea with lemon - it will allow to stop the process of nausea.

5) Do not use preparations from pain and diarrhea - they do not fix the situation, but only disguise this state of the body.

As you can see, it is not so difficult to determine the presence of nitrates in watermelon. Follow simple rules And be alert, do not use suspicious watermelons and do not let them go. Be healthy!

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 excessive feeding) watermelon rings when tapping, and the tip 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, so that only give them a commodity look, and 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 of yellow or purple are noticed, then this is a bad sign - such a watermelon, or not completely matured, or the result of the pest invasion, 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:

Rinse the stomach with a large number of warm, salted water or a weak-pink solution of manganese.
Take enterosorbents - drugs neutralizing poisons in the intestinal lumen. The most popular: activated carbon, "Polysorb MP", "Enterosgel", "Smekt".
Drink as much liquid as possible to strengthen the elimination of poisons from the body, as well as prevent dehydration.
Drink sweet tea with lemon after stopping nausea.
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

IN lately In many schools, scientific societies are being created in which students attribute to 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-nitrosamines with carcinogenic activity may be formed from nitrites in the presence of amines (contribute to education 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 washing of the stomach, receiving activated carbon, 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. (It was noted above that, taking into account the bioequivalent, the safe share of nitrates in food 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%), half of nitrates is lost, and public catering recommends a portion of boiled beets in 125 g, then 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 nitrosamines are found in smoked meat products, sausages prepared with the addition of nitrites - up to 80mkg / kg, in salt and smoked fish - up to 110 μg / kg. (In fresh meat and fish, nitrosicomin are not found or are in trace amounts - less than 1 μg / kg.) Nitrosamine dairy products are found mainly in the cheeses 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 in various cultures of non-etinakov. 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 increases.
An important role is played by the form of applied nitrogen fertilizers and the timing of their introduction. The maximum number of nitrates in vegetable products is accumulated when applying ammonia and sodium nitrate, and minimal - when 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 It is 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. Should pick up the varieties of plants in the least degree Accumulating nitrates, regularly destroy weeds, loosen the soil, widely use biological means of 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 of a lack of nitrogen in the plant, and dark purple - that the plant is provided with nitrogen.

Determination of nitrites in plants

Equipment and reagents.Blade, pipette, diphenylamine (crystalline), sulfuric acid (conc.), Streptocide solution (Tablet 0.5g dissolve in 50 ml pharmacy of 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 did not contain a large number of Nitrit. 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 more - it is necessary to put like a bouquet, into the water for direct 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 chemicals. 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.: high school, 1991, 288 p.;
Shtovova E.P. Experiments in chemistry with ecological orientation. Blagoveshchensk, 1993, 27 p.