Structural fructose. Physical properties of fructose. Difference from sugar
Monosaccharides Are the simplest carbohydrates. They do not undergo hydrolysis - they are not broken down by water into simpler carbohydrates.
The most important of monosaccharides are glucose and fructose... Another monosaccharide is also well known - galactose which is part of milk sugar.
Monosaccharides- solids, readily soluble in water, poorly - in alcohol and not at all soluble in ether.
Aqueous solutions are neutral to litmus. Majority monosaccharides possesses sweet taste.
Free in nature occurs mainly glucose... It is also a structural unit of many polysaccharides.
Other monosaccharides in a free state are rare and are mainly known as components oligo- and polysaccharides.
Trivial names monosaccharides usually have the ending " -ose»: glucose, galactose, fructose.
Chemical structure of monosaccharides.
Monosaccharides can exist in two forms: open(oxoform) and cyclical:
In solution, these isomeric forms are in dynamic equilibrium.
Open forms of monosaccharides.
Monosaccharides are heterofunctional compounds... Their molecules simultaneously contain carbonyl(aldehyde or ketone) and several hydroxyl groups (HE).
In other words, monosaccharides represent aldehyde alcohols(glucose) or ketone alcohols(fructose).
Monosaccharides containing an aldehyde group are called aldoses, and containing ketone - ketosis.
Structure aldose and ketosis in general form can be represented as follows:
Depending on the length of the carbon chain (from 3 before 10 carbon atoms) monosaccharides are divided into trioses, tetroses, pentoses, hexoses, heptoses, etc. Most common pentoses and hexoses.
Structural formulas glucose and fructose in their open forms they look like this:
So glucose is an aldohexose, i.e. contains an aldehyde functional group and 6 carbon atoms.
A fructose is an ketohexose, i.e. contains a keto group and 6 carbon atoms.
Cyclic forms of monosaccharides.
Monosaccharides open form can form cycles, i.e. close into rings.
Let's consider this with an example glucose.
Recall that glucose is six-atomic aldehyde alcohol(hexose). Its molecule simultaneously contains aldehyde group and several hydroxyl groups HE(OH is a functional group of alcohols).
When interacting with each other aldehyde and one of hydroxyl groups belonging to the same molecule glucose, postponing forms cycle, ring.
The hydrogen atom from the hydroxyl group of the fifth carbon atom goes into the aldehyde group and combines there with oxygen. The newly formed hydroxyl group ( HE) is called glycosidic.
In its properties, it differs significantly from alcohol(glycous) hydroxyl groups monosaccharides.
The oxygen atom from the hydroxyl group of the fifth carbon atom combines with the carbon of the aldehyde group, as a result of which a ring is formed:
Alpha- and beta glucose anomers differ in the position of the glycosidic group HE relative to the carbon chain of the molecule.
We have examined the emergence of a six-membered cycle. But cycles can also be five-membered.
This will happen if the carbon from the aldehyde group combines with the oxygen of the hydroxyl group at the fourth carbon atom, and not with the fifth, as discussed above. You will get a smaller ring.
Six-membered cycles are called pyranose, five-membered - furanose... The cycle names are derived from the names of related heterocyclic compounds - furana and pirana.
In the names of cyclic forms, along with the name of the monosaccharide itself, the "ending" is indicated - pyranose or furanose that characterize the size of the cycle. For example: alpha-D-glucofuranose, beta-D-glucopyranose, etc.
Cyclic forms of monosaccharides are thermodynamically more stable in comparison with open forms, so in nature they are more widespread.
(from ancient Greek γλυκύς - sweet) ( C 6 H 12 O 6) or grape sugar - the most important of monosaccharides; white crystals of sweet taste, easily soluble in water.
The glucose link is part of the series disaccharides(maltose, sucrose and lactose) and polysaccharides(cellulose, starch).
It is found in grape juice, in many fruits, as well as in the blood of animals and humans.
Muscle work is done mainly due to the energy released during oxidation glucose.
It is a hexahedral aldehyde alcohol:
It turns out when hydrolysis polysaccharides ( starch and cellulose) under the action of enzymes and mineral acids. In nature glucose formed by plants in the process photosynthesis.
Or fruit sugar C6H12O6 – monosaccharide, a companion of glucose in many fruit and berry juices.
Fructrose as a monosaccharide unit is a part of sucrose and lactulose.
Much sweeter than glucose. Mixtures with it are included in the composition of honey.
By structure fructose is a hexaatomic ketone alcohol:
Unlike glucose and other aldoses, fructose unstable in both alkaline and acidic solutions; decomposes under conditions of acid hydrolysis of polysaccharides or glycosides.
- monosaccharide, one of the most frequently occurring in nature six-alcohol alcohols - hexoses.
It exists in acyclic and cyclic forms.
Differs from glucose the spatial arrangement of groups at the 4th carbon atom.
Well soluble in water, poorly in alcohol.
In plant tissues galactose is a part of raffinose, melibiose, stachyose, as well as polysaccharides - galactans, pectin substances, saponins, various gums and mucus, gum arabic, etc.
In animals and humans galactose- an integral part of lactose (milk sugar), galactogen, group-specific polysaccharides, cerebrosides and mucoproteins.
It is included in many bacterial polysaccharides and can be fermented by the so-called lactose yeast. In animal and plant tissues galactose easily turns into glucose, which is better absorbed, can be converted into ascorbic and galacturonic acids.
1 (O) (O1 (O) CO) CO]
Fructose(arabino-hexulose, levulose, fruit sugar) is a monosaccharide, ketone alcohol, ketohexose, only the D-isomer is present in living organisms, in free form - in almost all sweet berries and fruits - it is included in sucrose and lactulose as a monosaccharide unit.
Fructose is a glucose isomer.
History
Unlike glucose and other aldoses, fructose is unstable in both alkaline and acidic solutions; decomposes under conditions of acid hydrolysis of polysaccharides or glycosides. The initial stage of the decomposition of fructose in the presence of acids is the dehydration of its furanose form with the formation of 5-methylolfurfural, which is the basis for the qualitative reaction to fructose in the presence of resorcinol - Selivanov's test:
Fructose is oxidized by KMnO4 in an acidic environment, forming oxalic acid and tartaric acid.Fructose and edible sugar
The sucrose (food sugar) molecule consists of two simple saccharides: glucose and fructose. In the body, sucrose is broken down into glucose and fructose. Therefore, in its action sucrose is equivalent to a mixture of 50% glucose and 50% fructose.
Finding
It makes up 80% of honey. It is found in almost all sweet berries and fruits.
Harm
A new study by scientists from the University of California has shown that excessive concentrations of fructose can damage hundreds of genes in the brain. These genes are associated with many diseases, from diabetes and cardiovascular disease to Alzheimer's disease and attention deficit hyperactivity disorder. Information about the dangers of high concentrations of fructose is of great importance, since this sweetener in one form or another is used by all people. Fructose is found in most baby foods and fruits, although the fiber in fruits slows down the body's absorption of sugar and contains other useful material protecting the brain.
British scientists conducted a series of experiments on rats and sequenced more than 20,000 genes in the rat brain. As a result, in rats that were on a fructose diet, more than 700 genes in the hypothalamus (the main metabolic center of the brain) and more than 200 genes in the hippocampus (regulating learning and memory) were changed. These changes were caused by fructose and are among those that regulate metabolism, cell communication, and inflammation. Disorders in these genes can trigger Parkinson's disease, depression, bipolar disorder, and other brain diseases. Of the nine hundred genes, the Bgn and Fmod genes are the first to change, triggering a cascade effect involving hundreds of other genes.
Thus, excess fructose poses a serious danger to the body. Perhaps the current prevalence of brain and metabolic diseases is largely related to the increase in fructose consumption.
Fortunately, until scientists find a way to solve the problem, we have a chance to reduce Negative influence fructose. The researchers also found that the effects of fructose exposure could be offset by intake of docosahexaenoic acid (DHA) of the omega-3 fatty acid class. DHA returns damaged genes to normal. Some DHA is found in wild salmon meat, fish oil, walnuts, flax seeds, fruits and vegetables. The problem is that we consume much more fructose.
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Excerpt from Fructose
- But how is his wound? In general, what position is he in?- You, you ... will see, - only Natasha could say.
They sat for some time downstairs near his room in order to stop crying and enter him with calm faces.
- How did the whole illness go? How long has it gotten worse? When did it happen? - asked Princess Marya.
Natasha said that at first there was a danger from fever and suffering, but in Trinity this passed, and the doctor was afraid of one thing - Antonov's fire. But this danger, too, was over. When we arrived in Yaroslavl, the wound began to fester (Natasha knew everything about suppuration, etc.), and the doctor said that suppuration could go right. A fever developed. The doctor said that this fever was not so dangerous.
“But two days ago,” Natasha began, “suddenly it happened…” She held back her sobs. “I don’t know why, but you will see what he has become.
- Weakened? lost weight? .. - asked the princess.
- No, not that, but worse. You will see. Ah, Marie, Marie, he is too good, he cannot, he cannot live ... because ...
When Natasha, with her habitual movement, opened his door, letting the princess in front of her, Princess Marya already felt ready sobs in her throat. No matter how much she prepared herself or tried to calm down, she knew that she would not be able to see him without tears.
Princess Marya understood what Natasha understood in words: it happened two days ago. She understood that this meant that he had suddenly softened, and that these softening, these tenderness were signs of death. Approaching the door, she already saw in her imagination that face of Andryusha, which she had known since childhood, gentle, meek, tender, which so rarely happened to him and therefore always had such a strong effect on her. She knew that he would say quiet, tender words to her, like those that her father had told her before he died, and that she could not bear it and would burst into tears over him. But, sooner or later, it had to be, and she entered the room. The sobs came closer and closer to her throat, while with her short-sighted eyes she made out more clearly and more clearly his form and searched for his features, and so she saw his face and met his gaze.
He was lying on the sofa, covered with pillows, in a furry squirrel robe. He was thin and pale. One thin, transparent white hand he was held by a handkerchief, with the other he, with quiet movements of his fingers, touched his thin, overgrown mustache. His eyes were looking at those who entered.
Seeing his face and meeting his gaze, Princess Marya suddenly moderated the speed of her step and felt that her tears had suddenly dried up and her sobs had stopped. Catching the expression on his face and look, she suddenly felt intimidated and felt guilty.
"But what am I to blame for?" She asked herself. "In the fact that you live and think about living things, and I! .." - answered his cold, stern look.
There was almost hostility in his deep, not out of himself, but in himself, when he slowly looked around at his sister and Natasha.
He kissed his sister hand in hand, according to their habit.
- Hello, Marie, how did you get there? - he said in a voice as even and alien as his gaze was. If he had screamed with a desperate cry, then this cry would have terrified Princess Mary less than the sound of this voice.
- And you brought Nikolushka? He said, also evenly and slowly, and with an obvious effort to remember.
- How is your health now? - said Princess Marya, herself surprised at what she was saying.
`` This, my friend, you have to ask the doctor, '' he said, and, apparently making another effort to be gentle, he said with one mouth (it was obvious that he did not think what he was saying): `` Merci, chere amie , d "etre venue. [Thank you dear friend for coming.]
Princess Marya shook his hand. He winced slightly at the squeeze of her hand. He was silent, and she did not know what to say. She understood what had happened to him in two days. In his words, in his tone, especially in this gaze - a cold, almost hostile gaze - there was a terrible alienation for a living person from everything worldly. He evidently had difficulty understanding now all living things; but at the same time it was felt that he did not understand the living, not because he was deprived of the power of understanding, but because he understood something else, something that the living did not understand and could not understand and that absorbed him in everything.
- Yes, that's how strange fate brought us together! He said, breaking the silence and pointing at Natasha. - She keeps following me.
Princess Marya listened and did not understand what he was saying. He, sensitive, gentle Prince Andrew, how could he say this with the one he loved and who loved him! If he had thought to live, he would have said it in a less coldly offensive tone. If he did not know that he was going to die, how could he not feel sorry for her, how could he say this in front of her! One explanation could only be for this, this is that he did not care, and all the same because something else, the most important, was revealed to him.
The conversation was cold, incoherent, and interrupted incessantly.
“Marie drove through Ryazan,” Natasha said. Prince Andrew did not notice that she was calling his sister Marie. And Natasha, when he called her that, for the first time noticed it herself.
- Well, what then? - he said.
- She was told that Moscow was all burnt down, completely, that as if ...
Natasha stopped: it was impossible to speak. He obviously made an effort to listen, and yet he could not.
“Yes, it’s burned out, they say,” he said. - This is very sorry, - and he began to look ahead, absentmindedly spreading his mustache with his fingers.
- Have you met Count Nikolai, Marie? - said Prince Andrey suddenly, apparently wishing to please them. “He wrote here that he liked you very much,” he continued simply, calmly, apparently unable to understand all the complex meaning that his words had for living people. “If you fell in love with him too, it would be very good ... for you to marry,” he added somewhat more quickly, as if delighted with the words that he had been looking for for a long time and found at last. Princess Marya heard his words, but they had no other meaning for her, except that they proved how terribly distant he was now from all living things.
- What to say about me! She said calmly and looked at Natasha. Natasha, feeling her gaze on her, did not look at her. Again everyone was silent.
- Andre, you want ... - Princess Marya suddenly said in a shuddering voice, - do you want to see Nikolushka? He thought about you all the time.
Prince Andrey smiled slightly for the first time, but Princess Marya, who knew his face so well, realized with horror that it was not a smile of joy, not tenderness for her son, but a quiet, meek mockery of what Princess Marya used, in her opinion , the last resort to bring him to his senses.
Fructose is a natural sugar found in free form in almost all sweet fruits, vegetables, and honey. Fructose (F.) stabilizes blood sugar levels, strengthens the immune system, and reduces the risk of caries and diathesis in children and adults. Serious advantages of fructose over sugar are associated with differences in the absorption of these products by the body.
Features of fructose
The sweetness of fructose is due to the accumulation of so-called hydroxyl groups in its molecules. They melt when heated. And when they burn, they become the cause of charring. By the way, fructose is twice as sweet as glucose.
There is such a scientific term - passive diffusion. So from the digestive tract, fructose is absorbed in this way. Once in the intestine, under the action of enzymes, it can undergo fermentation. Depending on the type of this very fermentation, it produces less or more, for example, lactic acid or acetic acid, even alcohol.
The peculiarity of fructose is that, apart from liver cells, practically no others can use it. It is almost completely absorbed by the liver cells. It is also converted and stored there in the form of the so-called glycogen.
Physical properties
Fructose forms anhydrous crystals in the form of needles, melting point 102-105 C. Molecular weight 180.16; specific gravity 1.60 g / cm3; caloric value is approximately the same as that of other sugars, 4 kcal per 1 g. Fructose is characterized by some hygroscopicity. Concentrated fructose formulations retain moisture. Fructose is readily soluble in water and alcohol. At 20 ° C, a saturated fructose solution has a concentration of 78.9%, a saturated sucrose solution - 67.1%, and a saturated glucose solution - only 47.2%. The viscosity of fructose solutions is lower than the viscosity of sucrose and glucose solutions.
Biological properties
Unlike glucose, fructose is absorbed from the human digestive tract only through passive diffusion. This process takes a comparatively long time. Fructose metabolism is rapid and occurs mainly in the liver, but also in the intestinal walls and in the kidneys due to the special chain of fructose-1-phosphate, which is not regulated by insulin. It follows that fructose is useful as a sweetener and carbohydrate source for diabetic patients.
Daily rate
Fructose is believed to be lower in calories than other carbohydrates. 100 grams of monosaccharide contains 390 calories.
Signs of a substance deficiency in the body:
- prostration;
- irritability;
- depression;
- apathy;
- nervous exhaustion.
Excess symptoms:
- increased appetite;
- excess weight.
Fructose content in some foods
| Name | The amount of monosaccharide in 100 grams of the product, grams |
| Corn syrup | 90 |
| Rafinated sugar | 50 |
| Agave dry | 42 |
| Bee honey | 40,5 |
| Date fruit | 31,5 |
| Raisin | 28 |
| Fig | 24 |
| Chocolate | 15 |
| Dried apricots | 13 |
| Ketchup | 10 |
| Jackfruit | 9,19 |
| Blueberry | 9 |
| Grapes "Kishmish" | 8,1 |
| Pears | 6,23 |
| Apples | 5,9 |
| Persimmon | 5,56 |
| Bananas | 5,5 |
| Cherries | 5,37 |
| Cherry | 5,15 |
| Mango | 4,68 |
| Kiwi | 4,35 |
| Peaches | 4 |
| Grapes "Muscat" | 3,92 |
| Papaya | 3,73 |
| Red and white currants | 3,53 |
| Plum (cherry plum) | 3,07 |
| Watermelon | 3,00 |
| Feijoa | 2,95 |
| Oranges | 2,56 |
| Tangerines | 2,40 |
| Raspberries | 2,35 |
| Strawberry | 2,13 |
| Corn | 1,94 |
| A pineapple | 1,94 |
| Melon | 1,87 |
| White cabbage | 1,45 |
| Zucchini (zucchini) | 1,38 |
| Sweet pepper (Bulgarian) | 1,12 |
| Cauliflower | 0,97 |
| Apricot | 0,94 |
| Cucumber | 0,87 |
| Sweet potato | 0,70 |
| Broccoli | 0,68 |
| Cranberry | 0,63 |
| Potato | 0,5 |
Benefits of fructose
- The good quality of this product is that its use does not lead to a sharp increase in blood sugar levels. It turns out that fructose does not release hormones in the intestines that stimulate the production of insulin. This mechanism of work makes it available for use by people with diabetes.
- This product is considered, in comparison with other carbohydrates, and less high in calories. 100 g contains 400 calories. So, by adding this particular ingredient to food, you can achieve a significant decrease in the calorie content of foods.
- Has fructose and tonic effect. Accumulating in the liver in the form of glycogen, it promotes recovery, and the fastest, after overloading. Whether they are physical or mental. From this perspective, it is recommended for athletes, and just people who lead a fairly active lifestyle.
- Another plus in the piggy bank of the benefits of fructose is that it does not cause tooth decay. It also accelerates the breakdown of alcohol in the blood.
- It is considered fructose and one of the best sweeteners. After all, there are no preservatives in it. And if sugar in baked goods is replaced with fructose, then such a product will be able to stay fluffy and soft longer.
- It turned out that the use of fructose not only insures against the development of diabetes, but also can increase the breakdown of alcohol in the blood of those who took an extra dose. In some cases, alcohol poisoning is treated this way - a fructose solution is injected intravenously.
- English dentists discovered another useful ability of fructose - they noticed that the yellow plaque that forms on the teeth after eating is much weaker and better removed if a person consumed fructose, rather than sugar. To verify this, we conducted an experiment on two groups of students. One of them ate using only fructose as sugar, the other - sucrose. In the first group, the incidence of caries was 30 percent lower. The reason is that the plaque formed when sucrose is consumed contains a dense substance dextran, and when fructose predominates in the diet, plaque is formed from an easily disintegrating compound.
- Fructose has another very important role in the body. When a person consumes a lot of fructose, the blood sugar does not rise as when glucose is consumed. The fact is that fructose very quickly becomes part of the compounds that supply the body with energy, therefore, in a state of stress, maximum stress, it is better to eat fruits and honey than sugar or chocolate - fructose will provide the body with energy much faster. Special studies have shown that if athletes took fructose before the competition, then the consumption of glycogen in the muscles was two times less than when using sucrose.
Disadvantages of fructose
- Fructose causes severe allergies in some people. Such patients cannot eat any fruits at all. Even vegetables are contraindicated. Foods based on these ingredients are also not recommended. Only this is very individual. After all, any substances can be allergens.
- Fructose may also be the culprit for excess weight. This is facilitated by its peculiarity to create a feeling of hunger. It turns out that with prolonged and excessive use, this product can cause disruptions in the production of certain hormones, which play a very important role. These hormones are called insulin and leptin. Without them, our body is not able to regulate the energy balance.
- More than acceptable consumption of fructose can cause cardiovascular disease.
- Studies by Israeli scientists who have conducted experiments on mice have shown that fructose can even lead to premature aging of the body.
The listed disadvantages of fructose do not mean that it is immediately necessary to abandon it and the products in which it is present, to give up. Moderate consumption of this natural sugar substitute does not lead to complications, but on the contrary brings significant benefits. The optimal norm for an adult is 45 g per day.
The use of fructose in diabetes mellitus
Fructose has a low glycemic index, so people with insulin-dependent type 1 diabetes can easily consume it in reasonable quantities.
The processing of fructose insulin requires five times less than the processing of glucose. It should be noted that fructose is not able to cope with hypoglycemia (lowering blood sugar levels), since fructose-containing foods do not cause a sharp increase in blood sugar levels.
Type 2 diabetics (most often these people are obese) should limit the amount of sweetener to 30 grams. Otherwise, the body will be harmed.
Fructose for pregnant and lactating women
During the period of bearing a child future mom enters the risk zone for impaired carbohydrate metabolism. This issue is acute if a woman was overweight even before pregnancy. As a result, fructose will contribute to further weight gain, and therefore create problems with bearing a baby, childbirth and increase the risk of developing gestational diabetes mellitus... Due to obesity, the fetus can be large, which will complicate the passage of the baby through the birth canal.
In addition, there is an opinion that if a woman consumes a lot of fast carbohydrates during pregnancy, this leads to a bookmark more fat cells in the baby than usual, which in adulthood causes a tendency to obesity. During the period breastfeeding it is also better to refrain from taking crystalline fructose, since part of it is still transformed into glucose, which undermines mom's health.
The use of fructose
Fructose in diabetes is just one of the medical prescriptions. So, doctors prescribe intravenous monosugar for alcohol poisoning. The medicine does not cause side effects, but most importantly, it significantly speeds up the metabolism of alcohol. It is quickly broken down and excreted from the body.
The question does not arise and is it possible for babies to fructose. They are able to assimilate monosugar as early as two days of age. But glucose and galactose are often rejected by children's organisms. Hence the intolerance of many milk formulas. So doctors prescribe fructose as a medicine in order to normalize digestion and allow the newborn to eat well.
Fructose is a remedy for hypoglycemia. This pathology is associated with low blood sugar. Habitual sucrose only contributes to hypoglycemic reactions. In contrast, fructose in honey and fruits maintains proper sugar levels. For the proper effect, doctors prescribe the drug in pure form, in tablets and powders.
The composition of fructose has also attracted the interest of specialists in soap making. Monosugar is added to household chemicals to increase foam stability. In addition, fructose moisturizes and nourishes the skin. The additive gives the soap a special scent. Seems to smell like dried fruit. In fact, it is the fructose flavor.
- It is very important to understand that there is a huge difference between natural fructose, which is part of vegetables and fruits, and food, which is artificially added to various products, just like tasty and healthy food differs from substitutes. Natural fructose is a completely harmless substance. It does not increase blood fat levels - provided it is consumed in moderation. In addition, we must not forget that from real fruits, together with fructose, we get vitamins, antioxidants, trace elements and dietary fiber. By the way, thanks to the latter, natural fructose is absorbed more slowly and leads to a gradual increase in blood sugar levels.
- Processed, food-grade fructose is perceived by the body as regular white sugar. Like him, it quickly raises blood sugar, the excess is converted to fat and accumulates in adipose tissue. The result is not sweet at all: weight gain, increased blood fat levels, the development of diabetes, an increase in blood pressure.
- Scientists and doctors have long been concerned about excess processed fructose in our diets. American researchers never tire of repeating to their compatriots that addiction to sweet junk food is the first step to heart attack, stroke and diabetes, not to mention obesity. Italian scientists conducted a study involving 45 thousand people and found that women who consume a lot of sugary foods, including honey, desserts and sweets, are 2 times more likely to suffer from heart disease than those who base their menu on complex carbohydrates (pasta and wholemeal bread, cereals, vegetables).
- Another paradox of fructose is that it causes ... hunger. How can this be, you ask. We will not torment you with the description of the research. You yourself have probably noticed that overweight people often suffer from increased appetite. Having eaten one piece of cake, they are able to immediately pounce on the second. The fat men are not to blame: food fructose tells them to do so. It affects not only fats, but also the hormone leptin, which in our body is responsible for feeling full. Fructose suppresses the production of this hormone, and a person who has eaten fruit sugar feels hungry.
- Fructose works the same way for sports enthusiasts who replenish themselves with energy bars before training.
Avoiding fructose
It is not just difficult to immediately and abruptly give up sugar - it is almost impossible: it is included in many products, including those containing fructose. Therefore, you should not give up sugar completely. Just start limiting your consumption. To make things easier for yourself, counter sugar with protein, especially for lunch and breakfast. Protein will help when your body shows the first signs of resistance, says Catelin Des Maysons, professor of nutritional and natural nutrition in Albuquerque. Typical snacks she recommends are eggs and toast, boiled fish and salad or cheese pita.
Then start limiting the consumption of white flour products: they always put sugar in them. Substitute foods made from brown rice, oats, and coarse grains. When you feel comfortable, start eliminating sugar-containing candies and refined sugar from your diet, which you usually put in tea.
Eat more fruits if you feel tired and exhausted. They are rich in natural sugars, give you the energy you need and raise your blood sugar to the right level much better than refined sugar, says Paul Sanders, a naturopath and professor at the Canadian College of Naturopathic Medicine in Toronto.
Dr. Nan Lu, director of the International Center for Traditional Chinese Medicine in New York, recommends eating melon, pears, almonds and ginger. And to better cope with feelings of depression, buy a complex of B vitamins.
Fructose is a monosaccharide that is present in free form in sweet fruits, vegetables, and honey.
The compound was first synthesized in 1861 by the Russian chemist A.M. Butler by condensation of formic acid under the action of catalysts: barium hydroxide and calcium.
What is fructose?
It is a white crystalline powder, readily soluble in water, which is twice as sweet and five times as sweet.
The chemical formula of the compound is C6H12O6.
Strengthens the immune system, relieves fatigue, stabilizes blood sugar levels, prevents caries and diathesis, gives strength and energy to the body.
Daily rate
Fructose is believed to be lower in calories than others. 100 grams of monosaccharide contains 390 calories.
Signs of a substance deficiency in the body:
- prostration;
- irritability;
- depression;
- apathy;
- nervous exhaustion.
Excess symptoms:
- increased appetite;
- excess weight.
Remember, if there is too much fructose in the human body, it is converted into fat and enters the bloodstream in the form of triglycerides. As a result, the risk of developing heart disease increases.
The need for fructose increases with active mental, physical activity associated with significant energy consumption, and decreases in the evening / night, during rest, with excess body weight. The B: W: Y ratio in the monosaccharide is 0%: 0%: 100%.
However, do not rush to classify the substance as a safe product, since there is a hereditary genetic disease - fructosemia. It indicates defects in enzymes (fructose - 1 - phosphataldolase, fructokinase) in the human body that break down the compound. As a result, fructose intolerance develops.
Fructosemia is found in childhood, from the moment fruit and vegetable juices and puree are introduced into the child's diet.
Symptoms of the disease:
- drowsiness;
- vomit;
- diarrhea;
- pallor of the skin;
- hypophosphatemia;
- aversion to sweet foods;
- lethargy;
- increased sweating;
- enlargement of the liver in size;
- hypoglycemia;
- stomach ache;
- hypotrophy;
- ascites;
- signs of gout;
- jaundice.
The form of fructosemia depends on the degree of lack of enzymes (enzymes) in the body. Distinguish between light and heavy, in the first case, a person can use a monosaccharide in a limited amount, in the second - not, since when it enters the body, it causes acute hypoglycemia and poses a danger to life.
Benefit and harm
V natural form, in the composition of fruits, vegetables and berries, fructose has a beneficial effect on the body: it reduces inflammation in the oral cavity and the likelihood of caries development by 35%. In addition, the monosaccharide acts as a natural antioxidant, prolongs the shelf life of products, keeping them fresh.
Fructose does not cause allergies, is well absorbed by the body, prevents the accumulation of excess carbohydrates in tissues, reduces the calorie content of food and accelerates recovery from mental and physical stress. The compound exhibits tonic properties, therefore it is recommended for people with an active lifestyle, athletes.
Fructose is used in cooking as a sugar substitute, preservative and berry flavor enhancer in the following products:
- dairy products;
- sweet drinks;
- baking;
- jam;
- low-calorie desserts;
- berry salads;
- ice cream;
- canned vegetables, fruits;
- juices;
- jams;
- sweets for diabetics (chocolate, cookies, sweets).
Who should stop taking fructose?
First of all, people suffering from obesity should exclude the monosaccharide from the menu. Fruit sugar suppresses the production of the "satiety" hormone - peptin, as a result, the brain does not receive a signal of satiety, a person begins to overeat, gaining extra pounds.
In addition, the compound is recommended to be used with caution by those wishing to lose weight, patients with fructosemia, diabetes mellitus. Despite the low glycemic index of fructose (20 GI), 25% of it is nevertheless transformed into glucose (100 GI), which requires a rapid release of insulin. The rest is absorbed by diffusion through the intestinal wall. The metabolism of fructose ends in the liver, where it turns into fats and, when broken down, participates in gluconeogenesis, glycolysis.
Thus, the harm and benefits of the monosaccharide are obvious. The main condition is to observe moderation in use.
Natural sources of fructose
To avoid oversaturation of the body with sweet monosaccharide, consider which foods contain it in the maximum amount.
| Name | The amount of monosaccharide in 100 grams of the product, grams |
|---|---|
| Corn syrup | 90 |
| Rafinated sugar | 50 |
| Agave dry | 42 |
| Bee honey | 40,5 |
| Date fruit | 31,5 |
| Raisin | 28 |
| Fig | 24 |
| Chocolate | 15 |
| Dried apricots | 13 |
| Ketchup | 10 |
| Jackfruit | 9,19 |
| Blueberry | 9 |
| Grapes "Kishmish" | 8,1 |
| Pears | 6,23 |
| Apples | 5,9 |
| Persimmon | 5,56 |
| Bananas | 5,5 |
| Cherries | 5,37 |
| Cherry | 5,15 |
| Mango | 4,68 |
| 4,35 | |
| Peaches | 4 |
| Grapes "Muscat" | 3,92 |
| Papaya | 3,73 |
| Red and white currants | 3,53 |
| Plum (cherry plum) | 3,07 |
| Watermelon | 3,00 |
| Feijoa | 2,95 |
| Oranges | 2,56 |
| Tangerines | 2,40 |
| Raspberries | 2,35 |
| Strawberry | 2,13 |
| Corn | 1,94 |
| 1,94 | |
| Melon | 1,87 |
| White cabbage | 1,45 |
| Zucchini (zucchini) | 1,38 |
| Sweet pepper (Bulgarian) | 1,12 |
| Cauliflower | 0,97 |
| 0,94 | |
| Cucumber | 0,87 |
| Sweet potato | 0,70 |
| Broccoli | 0,68 |
| Cranberry | 0,63 |
| Potato | 0,5 |
"Harmful" sources of fructose are simple carbohydrates: gingerbread, jelly, sweets, muffins, jam, sesame halva, waffles. As a rule, manufacturers use the monosaccharide to make sweet products for diabetics, but it can be consumed in moderation. healthy people instead of sugar.
Who will win: glucose or fructose?
Glucose is a monosaccharide synthesized by the human body from carbohydrates to support the vital functions of cells. It is a universal source of energy for all internal organs and systems.
Fructose is a naturally occurring sugar found in fruits and vegetables.
After entering the body, food carbohydrates under the influence of amylases of the pancreas and salivary glands are broken down to glucose and are adsorbed in the intestine as monosaccharides. The sugars are then converted into energy, and their remains are stored as glycogen in muscle tissue and liver for daily use.
Galactose, glucose, fructose - hexose. They have the same molecular formula and differ only in the bond ratio to the oxygen atom. Glucose - belongs to the category of aldose or reducing sugars, and fructose - ketosis. Upon interaction, carbohydrates form the disaccharide sucrose.
The main difference between fructose and glucose is the way they are absorbed. For the absorption of the first monosaccharide, the enzyme fructokinase is required, for the second, glucokinase or hexokinase.
Fructose metabolism occurs in the liver, no other cells can use it. The monosaccharide transforms the compound into fatty acids without producing leptin and insulin secretion.
Interestingly, fructose releases energy more slowly than glucose, which, when ingested, is rapidly absorbed into the bloodstream. The concentration of a simple carbohydrate is regulated by adrenaline, glucagon, insulin. In addition, polysaccharides that enter the human body with food, medications are converted into glucose in the small intestine during digestion.
Which is better than fructose or sugar?
There is no definite answer to this question. In excessive concentrations, both carbohydrates negatively affect the human body. At the same time, nutritionists agree: to maintain health, it is better to give preference to fresh fruits and berries than synthesized sweeteners and store juices.
FAQ
Can crystalline fructose be given to children under one year old?
No, as the monosaccharide can cause atopic dermatitis in infants. Therefore, it is more than unreasonable to give any synthetic sugar (fructose, glucose) to babies. Replace rolls, sweets, cookies with natural fruits, dried fruits.
Can pregnant and lactating women eat fructose?
During the period of bearing a child, the expectant mother enters the risk zone for a violation of carbohydrate metabolism. This issue is acute if a woman was overweight even before pregnancy. As a result, fructose will contribute to further weight gain, and therefore create problems with bearing a baby, childbirth and increase the risk of developing gestational diabetes mellitus. Due to obesity, the fetus can be large, which will complicate the passage of the baby through the birth canal.
In addition, it is believed that if a woman consumes a lot of fast carbohydrates during pregnancy, this leads to the laying of more fat cells in the baby than usual, which in adulthood causes a tendency to obesity.
During breastfeeding, it is also better to refrain from taking crystalline fructose, since some of it is still transformed into glucose, which undermines mom's health.
What is sugar made of?
It is a disaccharide formed from A - glucose and B - fructose, which are linked together. To assimilate sugar, the human body spends calcium, which leads to the leaching of the building element from the bone tissue. In addition, expert reviews indicate that the disaccharide damages tooth enamel, causes fat deposition and accelerates aging. It forms a false feeling of hunger, depletes energy reserves, "captures" and removes B vitamins. Therefore, sugar is rightfully considered a "sweet poison" that slowly kills the body.
Is it possible to eat fructose with diabetes?
In moderation. Twelve grams of monosaccharide contains one bread unit.
Fructose is a carbohydrate with a low glycemic index (20) and a glycemic load of 6.6 grams; when it enters the body, it does not provoke fluctuations in blood sugar and sudden surges of insulin, like sugar. Due to this property, the monosaccharide is of particular value for insulin-dependent people.
For children diagnosed with diabetes mellitus, the permissible daily intake of carbohydrates is calculated based on the ratio of 0.5 grams of compound per kilogram of body weight, for adults this figure rises to 0.75.
What are the benefits and harms of fructose for diabetics?
After ingestion, the monosaccharide reaches intracellular metabolism without the intervention of insulin and is rapidly eliminated from the blood. Unlike glucose, fructose does not release gut hormones that stimulate insulin secretion. Despite this, some of the compound still turns into sugars. As a result, blood glucose levels rise smoothly.
The rate of sugar rise is influenced by the amount of fructose taken: the more you eat, the faster and higher it reaches the critical level.
Output
Fructose is a monosaccharide that supplies a person with energy.
In moderation, the substance is a good substitute for refined sugar, as it has a low glycemic index and increases blood glucose levels gradually. Has a tonic effect, promotes quick recovery of the body after intense training, does not cause caries. In addition, fructose accelerates the breakdown of alcohol in the blood, which contributes to its rapid elimination. As a result, the effect of intoxication on the body is reduced. In cooking, monosaccharide is used in baking bakery products, making preserves, jam.
Remember, excessive consumption of crystalline fructose, over 40 grams per day, can be harmful to health and lead to weight gain, the development of heart pathologies, allergies, and premature aging. Therefore, it is recommended to limit the consumption of artificial monosaccharide, and to increase the consumption of the natural one in the form of fruits, vegetables, dried fruits, berries.
Fructose is a natural sugar found in free form in almost all sweet fruits, vegetables, and honey. Fructose (F.) stabilizes blood sugar levels, strengthens the immune system, and reduces the risk of caries and diathesis in children and adults. Serious advantages of fructose over sugar are associated with differences in the absorption of these products by the body.
Features of fructose
The sweetness of fructose is due to the accumulation of so-called hydroxyl groups in its molecules. They melt when heated. And when they burn, they become the cause of charring. By the way, fructose is twice as sweet as glucose.
There is such a scientific term - passive diffusion. So from the digestive tract, fructose is absorbed in this way. Once in the intestine, under the action of enzymes, it can undergo fermentation. Depending on the type of this very fermentation, it produces less or more, for example, lactic acid or acetic acid, even alcohol.
The peculiarity of fructose is that, apart from liver cells, practically no others can use it. It is almost completely absorbed by the liver cells. It is also converted and stored there in the form of the so-called glycogen.
Physical properties
Fructose forms anhydrous crystals in the form of needles, melting point 102-105 C. Molecular weight 180.16; specific gravity 1.60 g / cm3; caloric value is approximately the same as that of other sugars, 4 kcal per 1 g. Fructose is characterized by some hygroscopicity. Concentrated fructose formulations retain moisture. Fructose is readily soluble in water and alcohol. At 20 ° C, a saturated fructose solution has a concentration of 78.9%, a saturated sucrose solution - 67.1%, and a saturated glucose solution - only 47.2%. The viscosity of fructose solutions is lower than the viscosity of sucrose and glucose solutions.
Biological properties
Unlike glucose, fructose is absorbed from the human digestive tract only through passive diffusion. This process takes a comparatively long time. Fructose metabolism is rapid and occurs mainly in the liver, but also in the intestinal walls and in the kidneys due to the special chain of fructose-1-phosphate, which is not regulated by insulin. It follows that fructose is useful as a sweetener and carbohydrate source for diabetic patients.
Daily rate
Fructose is believed to be lower in calories than other carbohydrates. 100 grams of monosaccharide contains 390 calories.
Signs of a substance deficiency in the body:
- prostration;
- irritability;
- depression;
- apathy;
- nervous exhaustion.
Excess symptoms:
- increased appetite;
- excess weight.
Fructose content in some foods
| Name | The amount of monosaccharide in 100 grams of the product, grams |
| Corn syrup | 90 |
| Rafinated sugar | 50 |
| Agave dry | 42 |
| Bee honey | 40,5 |
| Date fruit | 31,5 |
| Raisin | 28 |
| Fig | 24 |
| Chocolate | 15 |
| Dried apricots | 13 |
| Ketchup | 10 |
| Jackfruit | 9,19 |
| Blueberry | 9 |
| Grapes "Kishmish" | 8,1 |
| Pears | 6,23 |
| Apples | 5,9 |
| Persimmon | 5,56 |
| Bananas | 5,5 |
| Cherries | 5,37 |
| Cherry | 5,15 |
| Mango | 4,68 |
| Kiwi | 4,35 |
| Peaches | 4 |
| Grapes "Muscat" | 3,92 |
| Papaya | 3,73 |
| Red and white currants | 3,53 |
| Plum (cherry plum) | 3,07 |
| Watermelon | 3,00 |
| Feijoa | 2,95 |
| Oranges | 2,56 |
| Tangerines | 2,40 |
| Raspberries | 2,35 |
| Strawberry | 2,13 |
| Corn | 1,94 |
| A pineapple | 1,94 |
| Melon | 1,87 |
| White cabbage | 1,45 |
| Zucchini (zucchini) | 1,38 |
| Sweet pepper (Bulgarian) | 1,12 |
| Cauliflower | 0,97 |
| Apricot | 0,94 |
| Cucumber | 0,87 |
| Sweet potato | 0,70 |
| Broccoli | 0,68 |
| Cranberry | 0,63 |
| Potato | 0,5 |
Benefits of fructose
- The good quality of this product is that its use does not lead to a sharp increase in blood sugar levels. It turns out that fructose does not release hormones in the intestines that stimulate the production of insulin. This mechanism of work makes it available for use by people with diabetes.
- This product is considered, in comparison with other carbohydrates, and less high in calories. 100 g contains 400 calories. So, by adding this particular ingredient to food, you can achieve a significant decrease in the calorie content of foods.
- Has fructose and tonic effect. Accumulating in the liver in the form of glycogen, it promotes recovery, and the fastest, after overloading. Whether they are physical or mental. From this perspective, it is recommended for athletes, and just people who lead a fairly active lifestyle.
- Another plus in the piggy bank of the benefits of fructose is that it does not cause tooth decay. It also accelerates the breakdown of alcohol in the blood.
- It is considered fructose and one of the best sweeteners. After all, there are no preservatives in it. And if sugar in baked goods is replaced with fructose, then such a product will be able to stay fluffy and soft longer.
- It turned out that the use of fructose not only insures against the development of diabetes, but also can increase the breakdown of alcohol in the blood of those who took an extra dose. In some cases, alcohol poisoning is treated this way - a fructose solution is injected intravenously.
- English dentists discovered another useful ability of fructose - they noticed that the yellow plaque that forms on the teeth after eating is much weaker and better removed if a person consumed fructose, rather than sugar. To verify this, we conducted an experiment on two groups of students. One of them ate using only fructose as sugar, the other - sucrose. In the first group, the incidence of caries was 30 percent lower. The reason is that the plaque formed when sucrose is consumed contains a dense substance dextran, and when fructose predominates in the diet, plaque is formed from an easily disintegrating compound.
- Fructose has another very important role in the body. When a person consumes a lot of fructose, the blood sugar does not rise as when glucose is consumed. The fact is that fructose very quickly becomes part of the compounds that supply the body with energy, therefore, in a state of stress, maximum stress, it is better to eat fruits and honey than sugar or chocolate - fructose will provide the body with energy much faster. Special studies have shown that if athletes took fructose before the competition, then the consumption of glycogen in the muscles was two times less than when using sucrose.
Disadvantages of fructose
- Fructose causes severe allergies in some people. Such patients cannot eat any fruits at all. Even vegetables are contraindicated. Foods based on these ingredients are also not recommended. Only this is very individual. After all, any substances can be allergens.
- Fructose may also be the culprit for excess weight. This is facilitated by its peculiarity to create a feeling of hunger. It turns out that with prolonged and excessive use, this product can cause disruptions in the production of certain hormones, which play a very important role. These hormones are called insulin and leptin. Without them, our body is not able to regulate the energy balance.
- More than acceptable consumption of fructose can cause cardiovascular disease.
- Studies by Israeli scientists who have conducted experiments on mice have shown that fructose can even lead to premature aging of the body.
The listed disadvantages of fructose do not mean that it is immediately necessary to abandon it and the products in which it is present, to give up. Moderate consumption of this natural sugar substitute does not lead to complications, but on the contrary brings significant benefits. The optimal norm for an adult is 45 g per day.
The use of fructose in diabetes mellitus
Fructose has a low glycemic index, so people with insulin-dependent type 1 diabetes can easily consume it in reasonable quantities.
The processing of fructose insulin requires five times less than the processing of glucose. It should be noted that fructose is not able to cope with hypoglycemia (lowering blood sugar levels), since fructose-containing foods do not cause a sharp increase in blood sugar levels.
Type 2 diabetics (most often these people are obese) should limit the amount of sweetener to 30 grams. Otherwise, the body will be harmed.
Fructose for pregnant and lactating women
During the period of bearing a child, the expectant mother enters the risk zone for a violation of carbohydrate metabolism. This issue is acute if a woman was overweight even before pregnancy. As a result, fructose will contribute to further weight gain, and therefore create problems with bearing a baby, childbirth, and increase the risk of developing gestational diabetes mellitus. Due to obesity, the fetus can be large, which will complicate the passage of the baby through the birth canal.
In addition, it is believed that if a woman consumes a lot of fast carbohydrates during pregnancy, this leads to the laying of more fat cells in the baby than usual, which in adulthood causes a tendency to obesity. During breastfeeding, it is also better to refrain from taking crystalline fructose, since some of it is still transformed into glucose, which undermines mom's health.
The use of fructose
Fructose in diabetes is just one of the medical prescriptions. So, doctors prescribe intravenous monosugar for alcohol poisoning. The medicine does not cause side effects, but most importantly, it significantly speeds up the metabolism of alcohol. It is quickly broken down and excreted from the body.
The question does not arise and is it possible for babies to fructose. They are able to assimilate monosugar as early as two days of age. But glucose and galactose are often rejected by children's organisms. Hence the intolerance of many milk formulas. So doctors prescribe fructose as a medicine in order to normalize digestion and allow the newborn to eat well.
Fructose is a remedy for hypoglycemia. This pathology is associated with low blood sugar. Habitual sucrose only contributes to hypoglycemic reactions. In contrast, fructose in honey and fruits maintains proper sugar levels. For the proper effect, doctors prescribe the drug in its pure form, in tablets and powders.
The composition of fructose has also attracted the interest of specialists in soap making. Monosugar is added to household chemicals to increase foam stability. In addition, fructose moisturizes and nourishes the skin. The additive gives the soap a special scent. Seems to smell like dried fruit. In fact, it is the fructose flavor.
- It is very important to understand that there is a huge difference between natural fructose, which is part of vegetables and fruits, and food, which is artificially added to various products, just like tasty and healthy food differs from substitutes. Natural fructose is a completely harmless substance. It does not increase blood fat levels - provided it is consumed in moderation. In addition, we must not forget that from real fruits, together with fructose, we get vitamins, antioxidants, trace elements and dietary fiber. By the way, thanks to the latter, natural fructose is absorbed more slowly and leads to a gradual increase in blood sugar levels.
- Processed, food-grade fructose is perceived by the body as regular white sugar. Like him, it quickly raises blood sugar, the excess is converted to fat and accumulates in adipose tissue. The result is not sweet at all: weight gain, increased blood fat levels, the development of diabetes, an increase in blood pressure.
- Scientists and doctors have long been concerned about excess processed fructose in our diets. American researchers never tire of repeating to their compatriots that addiction to sweet junk food is the first step to heart attack, stroke and diabetes, not to mention obesity. Italian scientists conducted a study involving 45 thousand people and found that women who consume a lot of sugary foods, including honey, desserts and sweets, are 2 times more likely to suffer from heart disease than those who base their menu on complex carbohydrates (pasta and wholemeal bread, cereals, vegetables).
- Another paradox of fructose is that it causes ... hunger. How can this be, you ask. We will not torment you with the description of the research. You yourself have probably noticed that overweight people often suffer from increased appetite. Having eaten one piece of cake, they are able to immediately pounce on the second. The fat men are not to blame: food fructose tells them to do so. It affects not only fats, but also the hormone leptin, which in our body is responsible for feeling full. Fructose suppresses the production of this hormone, and a person who has eaten fruit sugar feels hungry.
- Fructose works the same way for sports enthusiasts who replenish themselves with energy bars before training.
Avoiding fructose
It is not just difficult to immediately and abruptly give up sugar - it is almost impossible: it is included in many products, including those containing fructose. Therefore, you should not give up sugar completely. Just start limiting your consumption. To make things easier for yourself, counter sugar with protein, especially for lunch and breakfast. Protein will help when your body shows the first signs of resistance, says Catelin Des Maysons, professor of nutritional and natural nutrition in Albuquerque. Typical snacks she recommends are eggs and toast, boiled fish and salad or cheese pita.
Then start limiting the consumption of white flour products: they always put sugar in them. Substitute foods made from brown rice, oats, and coarse grains. When you feel comfortable, start eliminating sugar-containing candies and refined sugar from your diet, which you usually put in tea.
Eat more fruits if you feel tired and exhausted. They are rich in natural sugars, give you the energy you need and raise your blood sugar to the right level much better than refined sugar, says Paul Sanders, a naturopath and professor at the Canadian College of Naturopathic Medicine in Toronto.
Dr. Nan Lu, director of the International Center for Traditional Chinese Medicine in New York, recommends eating melon, pears, almonds and ginger. And to better cope with feelings of depression, buy a complex of B vitamins.
