How are solid fats different from liquid fats? Vegetable fat - what is it? What products contain it

Animal (solid) fats.Benefit or harm? List of foods with animal fats

In this article, we will understand why we need fats our body, as well as why it cannot function normally without them. Next, let's talk about what they are animals And vegetable fats and what is the difference between them. However, let's take a closer look at animal fats. Let's start the article with the structure of fats.

The difference between animal and vegetable fats

Almost everyone knows that fats are animal and vegetable. It is generally accepted that animal fats - These are saturated bad fats, and vegetable These are healthy unsaturated fats. Basically, the sources of animal fats are animal foods, and vegetable fats are vegetable foods. Generally, animal fats are solid fats and vegetable fats liquid. The question logically arises, why are some liquid and others solid, and what is the difference between them?

This is due to their structure. Vegetable fats have double bond in fats, which give them mobility. If there is no such bond, then the molecule sustainable, which is typical for animal or solid fats. Now I will give a little explanation why nature ordered it this way. Everything is very simple, because unlike animals, plants do not move and stand still all the time. It is quite difficult for them to adapt, because if there is no sun or bad weather conditions, then they still cannot go anywhere. Therefore, in this case double bonds in fats are involved in various biochemical reactions. For example, a double bond means a free place in a molecule, therefore, any other molecule can be moved to this place and the properties of fat can be easily changed. Suppose turn it over dense fat during the cold. Hence, plants are adaptable creatures, that's why they have such fat. Animal fats have no free bonds, they are all clogged. However, it is easier for animals, for example, if it is hot, then in the shade, and if it is cold, then in a cave, etc. Animals actively move and change environmental conditions, and therefore they do not need to change the properties of fat. Hence, animal fats less flexible.

However animal fats not always solid. Plants and animals have both unsaturated and saturated fatty acids. All omega fats are unsaturated fats, and the numbers 3, 6, 9 - designation of double bonds. As you know, for example, sea fish, i.e. animal, rich .

What are saturated animal fats for?

Now in vogue low fat diets which are actually very harmful to the body. After all, people limit themselves in vital elements, without which the adequate functioning of the body is simply impossible. Of course, you will not die if you have little fat in your diet, but your well-being may worsen, because fats is a very important building element.

Fat is the basis of our work brain And. In the work of brain cells (neurons) are electrical impulses that run along wires, the shell of which consists of myelin- a substance consisting of 75% from "animal" saturated fats! If you limit your intake of animal fats, then your impulses will move poorly, therefore, everything will suffer Keywords: brain, coordination, nervous system, memory, muscle movements, learning ability, etc.

Were research, which showed that with a deficiency of fat in the diet, changes in brain tissue can occur. Fats are very important for pregnant women, because they are necessary for the development of the child's brain, so they are advised to consume a large amount caviar because it contains both saturated and unsaturated fats. If you are suffering memory problems then eat more fat.

According to statistics, girls are twice as likely to suffer from diseases , For example, asthma. And all why? After all, girls are more likely to avoid fatty in the diet, and oxygen is transported into the blood with the help of pulmonary surfactant- substances lining the lungs from the inside. It consists on 90% from fat, and their animal saturated fat. Pulmonary surfactant allows the alveoli not to collapse and carry as much oxygen as possible into the bloodstream. You can remember cases from life when people (more often girls) became ill in a stuffy room. They observed such symptoms: pallor, suffocation and fainting. This is all because these people are not eating enough animal fats. They often have hypoxia, lack of oxygen, which gives us energy and is involved in all processes. By the way, this is why girls often lean on sweets, because the oxygen-free breakdown of sugar gives us energy. Therefore, if you want to have healthy lungs eat enough animal fats.

Saturated animal fats very useful for men, because they are involved in the synthesis of the main male sex hormone -. Saturated fatty acids are essential for building cell membranes. Many vitamins belong to, therefore, if there is little fat, then there are few vitamins. These vitamins can be stored in your adipose tissue and feed you in winter. However, this applies to fat-soluble vitamins. See functions Saturated fats are high in fat, so you shouldn't cut them out of your diet.

How much animal fat do you need? Exaggerated harm of animal fats

Now there are many recommendations by the amount of animal fats in the human diet. For example, well-known American explorers advised to consume animal and vegetable fats in the ratio 50 to 50. Our Russian nutritionists and nutritionists of the Russian Academy of Medical Sciences believe that the ratio of animal and vegetable fats should be 30 to 70, i.e. animal fats need less. Choose for yourself who to trust.

However, for all the health benefits of fats, many people try to avoid animal fats in their diet for several reasons. reasons. The first reason is the most main is the fear of promotion cholesterol. People are afraid of heart disease, atherosclerosis, and so on. However, recent research shows that many of these facts are highly controversial. I advise you to read an interesting article about, which will impress you! The second point is that modern man consumes animal fats in large quantities in buns, sweets, sweets, etc. Therefore, nutritionists and beat the alarm. However, this is not the case, because more proportion of these fats are low-quality margarines. Or are they giving us Palm oil to replace animal fat, which is a saturated fat, but vegetable origin. It can now be found everywhere.

When real animals are saturated fats replace vegetable cheap analogues, then this is bad. After all, you overpay, since these analogues are much cheaper than real animal fat. And the main harm is that when you consume such products, you will have a deficit in real animal fats, for example, phospholipids. These ones two factors say that the average modern person has a low consumption of real animal fats, even low. After all, instead of them, we are slipped low-quality analogues and fakes.

Animal fats in food. main sources

Quite logically from the name it follows that the main sources of animal fats include products of animal origin. Can be distinguished 2 major source: lard (pure fat) and dairy products.

Lard or fat can be consumed in its pure form, but in most cases it is in meat that we eat. Even chicken breast contains a small amount of animal fat, while beef, pork and lamb contain much more. Ukrainians are among those who like to use lard in its pure form. Remember, it is 100% fat.

To the main dairy products, giving us high-quality animal fats, you can attributed: milk and cream, cottage cheese, real butter, etc. Percentage animal fats in these products may differ.

Basically everything. These are the main 2 sources that give our body high-quality animal fats. You must understand that sausages, sausages, sweets, confectionery, biscuits, waffles, sweets, etc., cannot supply our body with high-quality animal fats, because. there are very few of them. There are cheap vegetable analogues and margarine.

I advise you to read a separate article about and an article about, in which I described the whole truth about them (composition, how to choose, benefit or harm, etc.). After reading them, I am sure you will reconsider your attitude towards these sources of saturated fats.

Summary

The density and properties of fats are due to their chemical structure and the presence or absence of double bonds. If these bonds are not present, then fat saturated. Unsaturated fats are mainly vegetable fats, and saturated fats animal fats. Saturated animal fats are necessary for the functioning of the brain, central nervous system, and also for the functioning of the respiratory system. Saturated animal fats (particularly cholesterol) are involved in the synthesis testosterone, while unsaturated fats are needed to dissolve vitamins(fat soluble). Everything in the body cell membranes are made up of unsaturated fats.

In the modern age, people consume a large amount poor quality animal fats(margarines and vegetable oils), while testing deficit for quality animal fats. In its composition, animal fats contain saturated (there are more of them) and unsaturated fatty acids. And in some respects they even surpass vegetable fats(read articles about and about ).

The article is based on the materials of Tsatsoulina Boris.

What about oils?

Oils These are fats that are liquid at room temperature. They are used for cooking. The sources of oils are various plants and fish. The most common types of oils are as follows:

• sunflower oil
• olive oil
• cottonseed oil
• corn oil
• soybean oil

Some oils, such as walnut oils, are primarily used to add flavor to foods. Oils are found in some common foods such as:

• nuts
• olives
• some types of fish

Foods that consist primarily of oils include mayonnaise and salad dressings.

Most oils are high in monounsaturated and polyunsaturated fatty acids and low in saturated fats. Plant sourced oils do not contain cholesterol. However, some oils from plant sources, such as coconut oil, contain saturated fats.

Solid fats These are fats that are solid at room temperature. The sources of solid fats are animal fats. In addition, solid fats can be obtained from vegetable oils, thanks to a technology called hydrogenation. Common solid fats include:

• butter
• beef fat
• mutton fat
• pork fat
• margarine
• chicken fat

What is the difference between oils and solid fats?

All oils and fats are a mixture of saturated and unsaturated fatty acids. Solid fats contain more saturated fats and/or so-called trans fats. Oils contain more monounsaturated and polyunsaturated fatty acids. Eating saturated fats, trans fats, and cholesterol increases blood levels of low-density lipoprotein (LDL) cholesterol, which in turn increases the risk of heart disease. In order to reduce this risk, it is recommended to reduce the intake of saturated fats, trans fats and cholesterol.

Why is it so important to use oils?

Most oils that are consumed with food contain monounsaturated and polyunsaturated fatty acids. They should be predominantly used in order to prevent cardiovascular diseases.

Monounsaturated and polyunsaturated fatty acids are found in fish products, nuts, and vegetable oils. They do not cause an increase in blood cholesterol levels. In addition, oils are important sources of vitamin E.

While the consumption of oils is important for health, it must be remembered that oils do contain calories. Specifically, one teaspoon of oils and tallow contains approximately 120 calories. For this reason, you should still limit the intake of oils and solid fat with food.

This table shows the quantitative content of oils in some products:

All fats can cause a rancid taste and odor when exposed to oxygen. Manufacturers have three imperfect ways to prevent this: using an airtight seal combined with refrigeration, adding antioxidants to compete for oxygen, or hydrogenation, which stabilizes the oil but also creates trans fats, according to Eleanor Whitney and Sharon Rolfes in Understanding Nutrition. "

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Identification

Hydrogenated oils have undergone a chemical process that adds hydrogen atoms to monounsaturated or polyunsaturated fats to reduce double bonds. This process increases shelf life by making fats more saturated and therefore less prone to rancidity.

Some trans fats are created when hydrogen is added to vegetable oil during the hydrogenation process. Trans fats are harder than butter and less likely to spoil, so the food has a longer shelf life.

Power supplies

Most fats contain a mixture of saturated, monounsaturated, and polyunsaturated fatty acids. When vegetable oils are partially hydrogenated, they turn into margarines. Fatty acids filled completely with hydrogen atoms are saturated and usually solid at room temperature. Animal fats such as butter, beef and lard, as well as tropical oils such as coconut and palm, are composed primarily of saturated fatty acids.

Commercial baked goods such as cakes and cookies, as well as fried foods including french fries and donuts, may contain trans fats. Shortcuts and margarines can also be high in trans fat, notes the Harvard School of Public Health. In recent years, the use of trans fats in commercial products has decreased due to health concerns. Less than 0.5 grams can be rounded up to zero grams of trans fat on nutrition labels, so if you consume multiple servings of these foods, you may be over the recommended limits.

Considerations

Hydrogenation has two advantages. It extends the shelf life and changes the texture of foods. Hydrogenated fats form flaky crusts and creamy puddings. The downside of hydrogenation is that it makes saturated polyunsaturated fats saturated and reduces their health benefits. Another disadvantage is that some molecules that remain unsaturated change shape and become trans fatty acids. This different form affects their function in your body. Trans fatty acids behave more like saturated fats than unsaturated fats, and they can have similar adverse effects on your health.

Meaning

Hydrogenated fats raise cholesterol levels and therefore increase the risk of heart disease, according to the American Heart Association. Trans fats are bad on two counts, notes the Harvard School of Public Health. They raise your LDL, "bad" cholesterol, and lower your HDL, "good" cholesterol, so this combination of low HDL and high LDL increases your risk of heart disease in two ways. Cardiovascular disease is the leading cause of death in both men and women.

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Liquid fats, as mentioned above, are triglycerides of unsaturated unsaturated fatty acids, and solid fats are derivatives of saturated fatty acids. The process is carried out by heating in an autoclave to 160 - 200 C. Through the heated mixture of fat with a finely divided catalyst, a stream of hydrogen is passed under a pressure of 2 - 15 atm. As a result, fats are obtained that are similar in all respects to solid natural fats.

Liquid fats are unsuitable for the synthesis of soap and the production of margarine, therefore, by hydrogenation, they are converted into solid ones.

Liquid fats, which are glycerides of unsaturated acids, are capable of addition reactions.

Liquid fats differ from solid fats in that unsaturated acid residues predominate in their molecules.

Liquid fats and oils contain residues of unsaturated acids, solid fats are esters of saturated acids.

Liquid fats are of limited use as foodstuffs. The population is accustomed to the use of the most solid fats possible. In addition, natural animal and vegetable oils have a characteristic taste and smell that not everyone likes. Fish oils have a particularly unpleasant taste.

It is advisable to add liquid fats to mineral oils when machining steels with increased strength at low cutting speeds.

Liquid fats are esters of glycerol and, mainly, unsaturated (unsaturated) higher acids. This determines their ability to add hydrogen via double bonds in the presence of a nickel catalyst and, at the same time, to pass into the solid state.

Liquid fats and oils can be converted into solid fats by the catalytic addition of hydrogen at the double bonds of the unsaturated acids included in their composition. This method is called - hydrogenation (hardening) of fats. It was first developed in 1906 by the Russian scientist S. A. Fokin, and in 1909 he also implemented it on an industrial scale.

Liquid fats are converted into solid ones by a hydrogenation reaction.

Liquid fats are converted into solid fats by a hydrogenation reaction. Hydrogenation of fats consists in the addition of hydrogen at the site of a double bond break. It is carried out at 160 - 240 C in the presence of catalysts (metal nickel) under a hydrogen pressure of about 3 atm.

Liquid fats and oils contain residues of unsaturated acids, solid fats are esters of saturated acids.

Liquid fats, as already mentioned, are triglycerides of unsaturated fatty acids, and solid fats are derivatives of saturated fatty acids. Thus, the possibility of obtaining solid fats from liquid ones by hydrogenation is quite obvious. addition of hydrogen at the site of double bonds. The process is carried out by heating in an autoclave to 200 C. A stream of hydrogen is passed through the heated mixture of fat with a finely divided catalyst at a pressure of 2-15 atm. As a result, fats are obtained that are similar in all respects to solid natural fats.

natural compounds found in the tissues of animals, plants, seeds and fruits of various plants, in some microorganisms. As a rule, these are mixtures consisting of full esters of glycerol and fatty acids and having the composition

where R, R "and R are hydrocarbon residues (radicals) of fatty acids containing from 4 to 26 carbon atoms.

Back in the 17th century. German scientist, one of the first analytical chemists Otto Tachenius (16521699) was the first to suggest that fats contain a "hidden acid". In 1741 the French chemist Claude Joseph Geoffroy (16851752) discovered that when soap (prepared by boiling fat with alkali) is decomposed with acid, a mass is greasy to the touch. However, Geoffroy emphasized that this mass is not at all the original fat, since it differs from it in properties. The fact that fats and oils also contain glycerin was first discovered in 1779 by the famous Swedish chemist Carl Wilhelm Scheele. By heating olive oil with wet lead litharge (PbO) to obtain the ointment he needed (Scheele was an apothecary by profession), he isolated a previously unknown liquid substance from the mixture. Repeating experiments with lard, clove oil, other oils and fats, Scheele found that the substance he discovered is an integral part of all vegetable and animal fats.

In those days, when describing new substances, it was customary to indicate not only their physical and chemical properties, but also their taste. Therefore, it is not surprising that Scheele, who even tried to determine what hydrocyanic acid tastes like, also tried the substance he discovered. Fortunately, it turned out to be non-poisonous and even sweet. So he called it: "the sweet beginning of oils." In addition to glycerin, Scheele discovered previously unknown chemical compounds in the breakdown products of fats, which he called fatty acids.

For the first time, the chemical composition of fats was determined at the beginning of the last century by the French chemist Michel Eugene Chevreul, the founder of the chemistry of fats, the author of numerous studies of their nature, summarized in a six-volume monograph Chemical studies of bodies of animal origin. Chevreul lived an exceptionally fruitful and long life: he was born in 1786, three years before the storming of the Bastille, and died almost 103 years later, having caught a cold while inspecting the construction of the Eiffel Tower. More than two thousand scientists from all over Europe gathered for the celebrations dedicated to the centenary of Chevreul; at the banquet, the venerable professor danced famously with the youngest participant, eighteen-year-old Giselle Tifenot.

Acting with aqueous solutions of acids and alkalis on various fats, as a result of the hydrolysis (saponification) reaction, Scheele discovered glycerin and previously unknown chemical compounds - various fatty acids, many of which he gave names. And Scheele Chevreul called “sweet butter” glycerin (Greek glykeros sweet). As Scheele established, fats are similar in composition to the already known esters, which, upon hydrolysis, turn into alcohols and acids.

The formula and chemical structure of glycerin were established much later. It turned out that this substance is a trihydric alcohol HOCH 2 CH(OH)CH 2 OH, i.e. has three hydroxyl groups, so it can attach three acid molecules to form an ester glyceride. If all three hydroxyl groups have attached carboxylic acid residues, triglycerides are formed; upon hydrolysis, they decompose into glycerol and free acids:

It is from triglycerides that oils and fats are mainly composed.

In 1854, the French chemist Marcelin Berthelot (1827-1907) carried out an esterification reaction, that is, the formation of an ester between glycerol and fatty acids, and thus synthesized fat for the first time. In 1859, his compatriot Charles Wurtz (18171884), using the reaction named after him, synthesized fats by heating tribromopropane with "silver soaps", for example: CH 2 BrCHBrCH 2 Br + 3C 17 H 35 COOAg ® CH 2 (OOCC 17 H 35)CH(OOCC 17 H 35)CH 2 (OOCC 17 H 35) + 3AgBr. Similarly, mono- and diglycerides were obtained. In this way, "synthetic fats" can be obtained with any number of carbon atoms in the fatty acid chains. Of course, it is much easier and cheaper to get fats from natural sources, but Berthelot and Wurtz did not intend to replace natural fat with synthetic ones. The so-called “counter synthesis” carried out by them unambiguously proved the composition of natural fats. This method, along with the analysis of the substance under study, is often used in the study of complex organic compounds.

In its pure form, glycerin is a colorless, odorless, viscous liquid, heavier than water and easily mixed with it. Glycerin has a very high viscosity: at room temperature, it is a thousand times higher than the viscosity of water. The melting point of glycerin is +17.9 ° C; however, due to its high viscosity, it is very difficult to crystallize glycerol. With strong heating of glycerin, its molecules are split and a volatile, very caustic substance that causes lacrimation, acrylic aldehyde, or acrolein (from Latin acris caustic, pungent and oleum oil: HOCH 2 CH (OH) CH 2 OH ® CH 2 \u003d CHCHO + 2H 2 O. It is the formation of acrolein that explains why acrid smoke appears in the kitchen if oil or fat is overheated in a pan.

Different fats and oils can vary greatly in appearance, physical and chemical properties. These differences, firstly, are due to the fact that natural fats and oils are not individual compounds, but mixtures. Purified triglycerides are colorless, odorless compounds with specific physical properties: melting point, density, etc. So, tripalmitin full ester of glycerol and palmitic acid with 16 carbon atoms in the chain (systematic name 1,2,3-propanetrioltrihexadecanoate) has a density of 0.88 and melts at 66.4 ° C; tristearin (18 carbons per chain) melts at 73°C, trimyristin (14 carbons per chain) at 56.5°C, trilaurin (12 carbons) at 46.4°C, tricaprylin (8 carbons) at 10°C, triolein (18 carbons and one double bond) at 5.5°C, etc. Natural fats do not have a specific melting point, they often have an odor. This is because they contain a mixture of various glycerides, as well as free fatty acids, lipids, vitamins, carotene and other compounds. Thus, cod liver oil (“fish oil”) contains significant amounts of vitamins A and D and is used in medicine. And the liver of a polar bear contains such amounts of vitamin A that it can cause poisoning.

Secondly, the diversity of fats and oils is associated with the difference in the hydrocarbon radicals R, R "and R in their composition. These radicals can be the same or different, saturated or unsaturated, flexible (saturated hydrocarbon residues) and more rigid (unsaturated fatty acid residues with double bonds).At the same time, in one fat molecule there are at least two different radicals at the same time.These radicals can be saturated (they are denoted as S from the English saturated) and unsaturated (U unsaturated).The composition of triglycerides of natural fats depends on which of the three OH groups in glycerol terminal or central are substituted by the corresponding radicals.So, soybean oil contains 53.5% triglycerides UUU, 36.5% SUU, 6.0% SUS, 1.81 .9% SSU and USU and 0.3% USU, while beef tallow has a completely different fatty acid composition: 32.8% SUS, 28.8% SSS, 17.9% SUU, 15.8% SSU, and 2 each ,22.5% USU and UUU.In addition to the full esters of glycerol (triglycerides), fats in a small amount (13%) contain mono- and diglycerides, in which only one or two hydrogen atoms OH- are substituted (esterified). glycerol groups.

All this determines the appearance, physical and chemical properties of fats. So, triglycerides with saturated fatty acid residues are solid substances at room temperature: pork and mutton fat, palm oil, etc. Depending on the composition, they can soften at different temperatures (for example, palm oil at 3141 ° C). Fats with shorter carbon chains, as well as fats containing double bonds in these chains, are softer or liquid, the latter mainly include vegetable oils. This is because long, flexible, saturated hydrocarbon chains allow fat molecules to pack tightly together to form solid crystals. If the chains are unsaturated and more rigid, dense packing of glycerides and, accordingly, crystallization, is difficult, the result is fats that are liquid under normal conditions, called oils. That is why, despite the close structure, sunflower oil is liquid, lard is hard, and butter or margarine is soft and melts in your mouth.

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