Fatty acids are included. Monounsaturated fatty acids. Unsaturated acids for skin

Over 200 fatty acids have been found in nature, which are part of the lipids of microorganisms, plants and animals.

Fatty acids are aliphatic carboxylic acids (Figure 2). In the body, they can be both in a free state and serve as building blocks for most classes of lipids.

All fatty acids that make up fats are divided into two groups: saturated and unsaturated. Unsaturated fatty acids having two or more double bonds are called polyunsaturated. Natural fatty acids are very diverse, but have a number of common features. These are monocarboxylic acids containing linear hydrocarbon chains. Almost all of them contain an even number of carbon atoms (from 14 to 22, most often found with 16 or 18 carbon atoms). Fatty acids with shorter chains or with an odd number of carbon atoms are much less common. The content of unsaturated fatty acids in lipids is usually higher than that of saturated ones. Double bonds are typically between 9 and 10 carbons, are almost always separated by a methylene group, and are in the cis configuration.

Higher fatty acids are practically insoluble in water, but their sodium or potassium salts, called soaps, form micelles in water that are stabilized by hydrophobic interactions. Soaps have the properties of surfactants.

Fatty acids are:

- the length of their hydrocarbon tail, the degree of their unsaturation and the position of double bonds in fatty acid chains;

– physical and chemical properties. Typically, saturated fatty acids are solid at 22°C, while unsaturated fatty acids are oils.

Unsaturated fatty acids have a lower melting point. Polyunsaturated fatty acids oxidize faster in the open air than saturated ones. Oxygen reacts with double bonds to form peroxides and free radicals;

Table 1 - The main carboxylic acids that make up lipids

In higher plants, there are mainly palmitic acid and two unsaturated acids - oleic and linoleic. The proportion of unsaturated fatty acids in the composition of vegetable fats is very high (up to 90%), and of the limiting ones, only palmitic acid is contained in them in an amount of 10-15%.

Stearic acid is almost never found in plants, but is found in significant amounts (25% or more) in some solid animal fats (sheep and bull fat) and tropical plant oils (coconut oil). There is a lot of lauric acid in bay leaf, myristic acid in nutmeg oil, arachidic and behenic acid in peanut and soybean oils. Polyunsaturated fatty acids - linolenic and linoleic - make up the main part of linseed, hemp, sunflower, cottonseed and some other vegetable oils. The fatty acids of olive oil are 75% oleic acid.

In the body of humans and animals, such important acids as linoleic and linolenic acids cannot be synthesized. Arachidonic - synthesized from linoleic. Therefore, they must be ingested with food. These three acids are called essential fatty acids. The complex of these acids is called vitamin F. With a long absence of them in food, animals experience stunting, dryness and flaking of the skin, and hair loss. Cases of insufficiency of essential fatty acids have also been described in humans. So, in infants receiving artificial nutrition with a low fat content, scaly dermatitis may develop, i.e. symptoms of avitaminosis appear.

Recently, much attention has been paid to omega-3 fatty acids. These acids have a strong biological effect - they reduce platelet adhesion, thereby preventing heart attacks, lowering blood pressure, reducing inflammation in the joints (arthritis), and are necessary for the normal development of the fetus in pregnant women. These fatty acids are found in fatty fish (mackerel, salmon, salmon, Norwegian herring). It is recommended to eat sea fish 2-3 times a week.

Nomenclature of fats

Neutral acylglycerols are the main constituents of natural fats and oils, most often mixed triacylglycerols. By origin, natural fats are divided into animal and vegetable. Depending on the fatty acid composition, fats and oils can be liquid or solid in consistency. Animal fats (lamb, beef, lard, milk fat) usually contain a significant amount of saturated fatty acids (palmitic, stearic, etc.), due to which they are solid at room temperature.

Fats, which include a lot of unsaturated acids (oleic, linoleic, linolenic, etc.), are liquid at ordinary temperatures and are called oils.

Fats are usually found in animal tissues, oils - in the fruits and seeds of plants. The content of oils (20-60%) is especially high in the seeds of sunflower, cotton, soybeans, and flax. The seeds of these crops are used in the food industry to produce edible oils.

According to the ability to dry in air, oils are divided into: drying (linseed, hemp), semi-drying (sunflower, corn), non-drying (olive, castor).

Physical properties

Fats are lighter than water and insoluble in it. Highly soluble in organic solvents, such as gasoline, diethyl ether, chloroform, acetone, etc. The boiling point of fats cannot be determined, since when heated to 250 ° C, they are destroyed with the formation of aldehyde, acrolein (propenal), which strongly irritates the mucous membranes of the eyes, from glycerol during its dehydration.

For fats, there is a fairly clear relationship between the chemical structure and their consistency. Fats, in which the residues of saturated acids predominate -solid (beef, lamb and pork fat). If unsaturated acid residues predominate in fat, it hasliquid consistency. Liquid vegetable fats are called oils (sunflower, linseed, olive, etc. oils). The organisms of marine animals and fish contain liquid animal fats. into fat molecules greasy (semi-solid) consistency includes both the remains of saturated and unsaturated fatty acids (milk fat).

Chemical properties of fats

Triacylglycerols are capable of entering into all chemical reactions inherent in esters. The saponification reaction is of the greatest importance; it can occur both during enzymatic hydrolysis and under the action of acids and alkalis. Liquid vegetable oils are converted into solid fats by hydrogenation. This process is widely used to make margarine and cooking oil.

Fats with strong and prolonged shaking with water form emulsions - dispersed systems with a liquid dispersed phase (fat) and a liquid dispersion medium (water). However, these emulsions are unstable and quickly separate into two layers - fat and water. Fats float above water because their density is less than that of water (from 0.87 to 0.97).

Hydrolysis. Among the reactions of fats, hydrolysis is of particular importance, which can be carried out both with acids and bases (alkaline hydrolysis is called saponification):

Saponifiable lipids 2

Simple lipids 2

Fatty acids 3

Chemical properties of fats 6

ANALYTICAL CHARACTERISTICS OF FATS 11

Complex lipids 14

Phospholipids 14

Soaps and detergents 16

Hydrolysis of fats is gradual; for example, the hydrolysis of tristearin yields first distearin, then monostearin, and finally glycerol and stearic acid.

In practice, the hydrolysis of fats is carried out either by superheated steam, or by heating in the presence of sulfuric acid or alkalis. Excellent catalysts for the hydrolysis of fats are sulfonic acids obtained by sulfonation of a mixture of unsaturated fatty acids with aromatic hydrocarbons ( Petrov's contact). Castor seeds contain a special enzyme - lipase accelerating the hydrolysis of fats. Lipase is widely used in technology for the catalytic hydrolysis of fats.

Chemical properties

The chemical properties of fats are determined by the ester structure of triglyceride molecules and the structure and properties of hydrocarbon radicals of fatty acids, the residues of which are part of the fat.

Like esters fats enter into, for example, the following reactions:

– Hydrolysis in the presence of acids ( acid hydrolysis)

Hydrolysis of fats can also proceed biochemically under the action of the digestive tract enzyme lipase.

Hydrolysis of fats can proceed slowly during long-term storage of fats in an open package or heat treatment of fats in the presence of water vapor from the air. A characteristic of the accumulation of free acids in fat, which give the fat bitterness and even toxicity, is "acid number": the number of mg of KOH used for titration of acids in 1 g of fat.

– Saponification:

Most interesting and useful reactions of hydrocarbon radicals are double bond reactions:

– Hydrogenation of fats

Vegetable oils(sunflower, cottonseed, soybean) in the presence of catalysts (for example, sponge nickel) at 175-190 o C and a pressure of 1.5-3 atm are hydrogenated at double C \u003d C bonds of hydrocarbon radicals of acids and turn into solid fat. When so-called fragrances are added to it to give the appropriate smell and eggs, milk, vitamins to improve nutritional qualities, they get margarine. Salomas is also used in soap making, pharmacy (bases for ointments), cosmetics, for the manufacture of technical lubricants, etc.

– Addition of bromine

The degree of unsaturation of fat (an important technological characteristic) is controlled by "iodine number": number of mg of iodine used to titrate 100 g of fat as a percentage (analysis with sodium bisulfite).

– Oxidation

Oxidation with potassium permanganate in an aqueous solution leads to the formation of saturated dihydroxy acids (Wagner reaction)

rancidity

During storage, vegetable oils, animal fats, as well as fat-containing products (flour, cereals, confectionery, meat products) under the influence of air oxygen, light, enzymes, moisture acquire an unpleasant taste and smell. In other words, fat goes rancid.

Rancidity of fats and fat-containing products is the result of complex chemical and biochemical processes occurring in the lipid complex.

Depending on the nature of the main process occurring in this case, there are hydrolytic and oxidative rancidity. Each of these can be divided into autocatalytic (non-enzymatic) and enzymatic (biochemical) rancidity.

HYDROLYTIC RANCIENCY

At hydrolytic Rancidity is the hydrolysis of fat with the formation of glycerol and free fatty acids.

Non-enzymatic hydrolysis proceeds with the participation of water dissolved in fat, and the rate of fat hydrolysis at ordinary temperatures is low. Enzymatic hydrolysis occurs with the participation of the enzyme lipase on the surface of contact between fat and water and increases during emulsification.

As a result of hydrolytic rancidity, acidity increases, an unpleasant taste and smell appear. This is especially pronounced in the hydrolysis of fats (milk, coconut and palm), containing low and medium molecular weight acids, such as butyric, valeric, caproic. High molecular weight acids are tasteless and odorless, and an increase in their content does not lead to a change in the taste of oils.

OXIDATIVE RANCIENCY

The most common type of spoilage of fats during storage is oxidative rancidity. First of all, unsaturated fatty acids are oxidized, and not bound in triacylglycerols. The oxidation process can occur in non-enzymatic and enzymatic ways.

As a result non-enzymatic oxidation Oxygen attaches to unsaturated fatty acids at the double bond to form cyclic peroxide, which decomposes to form aldehydes, which give the fat an unpleasant odor and taste:

Also, non-enzymatic oxidative rancidity is based on chain radical processes involving oxygen and unsaturated fatty acids.

Under the action of peroxides and hydroperoxides (primary oxidation products), fatty acids are further decomposed and secondary oxidation products (carbonyl-containing) are formed: aldehydes, ketones and other substances that are unpleasant in taste and smell, as a result of which the fat becomes rancid. The more double bonds in a fatty acid, the higher the rate of its oxidation.

At enzymatic oxidation this process is catalyzed by the enzyme lipoxygenase to form hydroperoxides. The action of lipoxygenase is associated with the action of lipase, which pre-hydrolyzes fat.

ANALYTICAL CHARACTERISTICS OF FATS

In addition to the melting and solidification temperatures, the following values ​​are used to characterize fats: acid number, peroxide number, saponification number, iodine number.

Natural fats are neutral. However, during processing or storage due to hydrolysis or oxidation processes, free acids are formed, the amount of which is not constant.

Under the action of the enzymes lipase and lipoxygenase, the quality of fats and oils changes, which is characterized by the following indicators or numbers:

Acid number (Kh) is the number of milligrams of potassium hydroxide required to neutralize free fatty acids in 1 g of fat.

During storage of the oil, hydrolysis of triacylglycerols is observed, which leads to the accumulation of free fatty acids, i.e. to an increase in acidity. Increasing K.ch. indicates a decline in quality. The acid number is a standardized indicator of oil and fat.

Iodine number (Y.h.) - this is the number of grams of iodine added at the place of double bonds to 100 g of fat:

The iodine number allows you to judge the degree of unsaturation of the oil (fat), its tendency to dry out, rancidity and other changes that occur during storage. The more unsaturated fatty acids contained in the fat, the higher the iodine number. A decrease in the iodine number during storage of the oil is an indicator of its deterioration. To determine the iodine number, solutions of iodine chloride IC1, iodine bromide IBr or iodine in a sublimate solution are used, which are more reactive than iodine itself. The iodine number is a measure of the unsaturation of fatty acids. It is important for assessing the quality of drying oils.

Peroxide number (p.h.) shows the amount of peroxides in fat, expressed as a percentage of iodine isolated from potassium iodide by peroxides formed in 1 g of fat.

There are no peroxides in fresh fat, but when exposed to air, they appear relatively quickly. During storage, the peroxide value increases.

Saponification number (N.O. ) is equal to the number of milligrams of potassium hydroxide consumed during the saponification of 1 g of fat by boiling the latter with an excess of potassium hydroxide in an alcohol solution. The saponification number of pure triolein is 192. A high saponification number indicates the presence of acids with "smaller molecules". Low saponification numbers indicate the presence of higher molecular weight acids or unsaponifiables.

Oil polymerization. The reactions of autoxidation and polymerization of oils are very important. On this basis, vegetable oils are divided into three categories: drying, semi-drying and non-drying.

Drying oils in a thin layer they have the ability to form elastic, shiny, flexible and durable films in air, insoluble in organic solvents, resistant to external influences. The use of these oils for the preparation of varnishes and paints is based on this property. The most commonly used drying oils are shown in Table. 34.

Table 34. Characteristics of drying oils

The main characteristic feature of drying oils is the high content of unsaturated acids. To assess the quality of drying oils, the iodine number is used (it must be at least 140).

The drying process of oils is oxidative polymerization. All unsaturated fatty acid esters and their glycerides oxidize in air. Apparently, the oxidation process is a chain reaction leading to an unstable hydroperoxide, which decomposes to form hydroxy and keto acids.

Drying oils containing glycerides of unsaturated acids with two or three double bonds are used to prepare drying oils. To obtain drying oil, linseed oil is heated to 250-300 ° C in the presence of catalysts.

Semi drying oils (sunflower, cottonseed) differ from drying ones in a lower content of unsaturated acids (iodine number 127-136).

Non-drying oils (olive, almond) have an iodine value below 90 (for example, for olive oil 75-88).

Waxes

These are esters of higher fatty acids and higher monohydric alcohols of fatty (rarely aromatic) series.

Waxes are solid compounds with pronounced hydrophobic properties. Natural waxes also contain some free fatty acids and macromolecular alcohols. The composition of waxes includes both the usual ones contained in fats - palmitic, stearic, oleic, etc., and fatty acids characteristic of waxes, which have much larger molecular weights - carnoubic C 24 H 48 O 2, cerotinic C 27 H 54 O 2, montanic C 29 H 58 O 2, etc.

Among the macromolecular alcohols that make up waxes, one can note cetyl - CH 3 - (CH 2) 14 -CH 2 OH, ceryl - CH 3 - (CH 2) 24 -CH 2 OH, myricyl CH 3 - (CH 2) 28 -CH 2 OH.

Waxes are found in both animal and plant organisms and perform mainly a protective function.

In plants, they cover leaves, stems and fruits with a thin layer, thereby protecting them from wetting with water, drying out, mechanical damage and damage by microorganisms. Violation of this plaque leads to rapid deterioration of the fruit during storage.

For example, a significant amount of wax is released on the surface of the leaves of a palm tree growing in South America. This wax, called carnouba wax, is basically a cerotinic myricyl ester:

,

has a yellow or greenish color, is very hard, melts at a temperature of 83-90 0 C, goes to the manufacture of candles.

Among animal waxes, beeswax is the most important, honey is stored under its cover and bee larvae develop. In beeswax, palmitic-myricyl ether predominates:

as well as a high content of higher fatty acids and various hydrocarbons, beeswax melts at a temperature of 62-70 0 C.

Other representatives of animal wax are lanolin and spermaceti. Lanolin protects hair and skin from drying out, a lot of it is found in sheep's wool.

Spermaceti - a wax extracted from the spermaceti oil of the sperm whale cranial cavities, consists mainly (90%) of palmitic-cetyl ether:

solid, its melting point is 41-49 0 C.

Various waxes are widely used for the manufacture of candles, lipsticks, soaps, various plasters.

Fats in the human body play both an energy and a plastic role. In addition, they are good solvents for a number of vitamins and sources of biologically active substances.

Fat increases the palatability of food and causes a feeling of long-term satiety.

The role of fats in the process of culinary processing of food is great. They give it special tenderness, improve organoleptic qualities and increase nutritional value. Due to the low oxidizability of fat, 1 g of it during combustion gives 9.0 kcal, or 37.7 kJ.

There are protoplasmic fat, which is a structural element of the protoplasm of cells, and spare, or reserve, which is deposited in adipose tissue. With a lack of fat in the diet, disturbances occur in the state of the body (weakening of immunological and protective mechanisms, changes in the skin, kidneys, organs of vision, etc.). Animal experiments have shown a shortening of life expectancy with insufficient fat content in the diet of animals.

CHEMICAL COMPOSITION AND BIOLOGICAL VALUE OF FAT

Fatty acids are divided into limiting (saturated) and unsaturated (unsaturated). The most common saturated fatty acids are palmitic, stearic, butyric and caproic. Palmitic and stearic acids are high molecular weight and are solids.

Saturated fatty acids are found in animal fats. They have low biological activity and can have a negative effect on fat and cholesterol metabolism.

Unsaturated fatty acids are widely present in all dietary fats, but most of them are found in vegetable oils. They contain double unsaturated bonds, which determines their significant biological activity and ability to oxidize. The most common are oleic, linoleic, linolenic and arachidonic fatty acids, among which arachidonic acid has the highest activity.

Unsaturated fatty acids are not formed in the body and must be administered daily with food in the amount of 8-10 g. Sources of oleic, linoleic and linolenic fatty acids are vegetable oils. Arachidonic fatty acid is almost not found in any product and can be synthesized in the body from linoleic acid in the presence of vitamin B 6 (pyridoxine).

The lack of unsaturated fatty acids leads to growth retardation, dryness and inflammation of the skin.

Unsaturated fatty acids are part of the membrane system of cells, myelin sheaths and connective tissue. Their participation in fat metabolism and in the conversion of cholesterol into easily soluble compounds that are excreted from the body is known.

To meet the physiological needs of the body in unsaturated fatty acids, it is necessary to introduce 15-20 g of vegetable oil into the diet daily.

Sunflower, soybean, corn, linseed and cottonseed oils have a high biological activity of fatty acids, in which the content of unsaturated fatty acids is 50-80%.

The biological value of fats is characterized by their good digestibility and the presence in their composition, in addition to unsaturated fatty acids, tocopherols, vitamins A and D, phosphatides and sterols. Unfortunately, none of the dietary fats meet these requirements.

FAT-LIKE SUBSTANCES.

Certain value for the body and fat-like substances - phospholipids and sterols. Of the phospholipids, lecithin has the most active effect, which promotes the digestion and better metabolism of fats, and increases the separation of bile.

Lecithin has a lipotropic effect, i.e. it prevents fatty liver, prevents the deposition of cholesterol in the walls of blood vessels. A lot of lecithin is found in egg yolks, in milk fat, in unrefined vegetable oils.

The most important representative of sterols is cholesterol, which is part of all cells; especially a lot of it in the nervous tissue.

Cholesterol is part of the blood, is involved in the formation of vitamin D3, bile acids, hormones of the gonads.

Violation of cholesterol metabolism leads to atherosclerosis. From fats and carbohydrates in the human body per day, about 2 g of cholesterol is formed, 0.2-0.5 g comes with food.

The predominance of saturated fatty acids in the diet enhances the formation of endogenous (internal) cholesterol. The highest amount of cholesterol is found in brains, egg yolk, kidneys, fatty meats and fish, caviar, butter, sour cream and cream.

Cholesterol metabolism in the body is normalized by various lipotropic substances.

In the body there is a close relationship between the exchange of lecithin and cholesterol. Under the influence of lecithin, the level of cholesterol in the blood decreases.

To normalize fat and cholesterol metabolism, a diet rich in lecithin is necessary. With the introduction of lecithin into the diet, it is possible to reduce the level of cholesterol in the blood serum, even if foods containing a large amount of fat are included in the diet.

Overheated fats.

The production of crispy potatoes, fish sticks, frying canned vegetables and fish, as well as the preparation of fried pies and donuts has become widespread in nutrition. Vegetable oils used for these purposes are subjected to heat treatment in the temperature range from 180 to 250 °C. With prolonged heating of vegetable oils, the process of oxidation and polymerization of unsaturated fatty acids occurs, resulting in the formation of cyclic monomers, dimers and higher polymers. At the same time, the unsaturation of the oil decreases and the products of oxidation and polymerization accumulate in it. Oxidation products formed as a result of prolonged heating of the oil reduce its nutritional value and cause the destruction of phosphatides and vitamins in it.

In addition, this oil has an adverse effect on the human body. It has been established that prolonged use of it can cause severe irritation of the gastrointestinal tract and cause the development of gastritis.

Overheated fats also affect fat metabolism.

A change in the organoleptic and physico-chemical properties of vegetable oils used for frying vegetables, fish and pies usually occurs in case of non-compliance with the technology of their preparation and violation of the instructions “On the procedure for frying pies, using deep fat and controlling its quality”, when the duration of heating oil exceeds 5 hours, and the temperature is 190 °C. The total amount of fat oxidation products should not exceed 1%.

The body's need for fat.

Rationing of fat is carried out depending on the age of the person, the nature of his work activity and climatic conditions. In table. 5 shows the daily requirement for fats of the adult working population.

For young and middle-aged people, the ratio of protein to fat can be 1:1 or 1:1.1. The need for fat also depends on climatic conditions. In the northern climatic zones, the amount of fat can be 38-40% of the daily calorie content, in the middle - 33, in the southern - 27-30%.

Biologically optimal is the ratio in the diet of 70% animal fat and 30% vegetable fat. In adulthood and old age

the ratio can be changed in the direction of increasing the specific gravity of vegetable fats. This ratio of fats allows you to provide the body with a balanced amount of fatty acids, vitamins and fat-like substances.

Fat is an active reserve of energy material. With fats, the substances necessary to maintain the activity of the body come: in particular, vitamins E, D, A. Fats help the absorption of a number of nutrients from the intestines. The nutritional value of fats is determined by their fatty acid composition, melting point, the presence of essential fatty acids, the degree of freshness, and taste. Fats are made up of fatty acids and glycerol. The value of fats (lipids) is diverse. Fats are contained in cells and tissues, participating in metabolic processes.

Liquid fats are unsaturated fatty acids(most vegetable oils and fish fats contain them), in solid fats - saturated fatty acids - fats of animals and birds. Of the solid fats, mutton and beef fat are the most refractory and difficult to digest, and milk fat is the easiest. The biological value is higher than v fats rich in unsaturated fatty acids.

Of particular importance are POLYUNSATURATED ESSENTIAL FATTY ACIDS: linoleic and arachidonic. Like vitamins, they are almost never produced by the body and must be obtained from food. These substances are an important component of cell membranes, necessary to regulate metabolism, especially cholesterol metabolism, form tissue hormones (prostaglandins). Sunflower, corn and cottonseed oil contains about 50% linoleic acid. 15-25 g of these oils fill the daily requirement for essential fatty acids. This amount is increased to 25-35 g in atherosclerosis, diabetes mellitus e, obesity and other diseases. However, long-term use of very large amounts of these fats can be unfavorable for the body. These acids are relatively rich in fish fats, poor (3-5%) mutton and beef fats, butter.

Lecithin belongs to fat-like substances - phosphatides - which contributes to the digestion and good metabolism of fats and forms cell membranes together with protein. It also normalizes cholesterol metabolism.

Lecithin also has a lipotropic effect, since it reduces the concentration of fats in the liver, preventing its obesity in diseases and the action of various poisons. Fat-like substance cholesterol is involved in the formation of essential acids in the body. The deposition of cholesterol in the inner lining of the arteries is the main symptom of atherosclerosis.

Vegetable products do not contain cholesterol.

Cholesterol limit the diet to 300-400 mg per day with atherosclerosis, cholelithiasis, diabetes, decreased thyroid function, etc. However, it must be borne in mind that even in a healthy body, cholesterol is formed 3-4 times more than it comes with food. Increased cholesterol formation arises from various reasons, including malnutrition (excess of animal fats and sugar in food), eating disorders.

Cholesterol metabolism is normalized by essential fatty acids, lecithin, methionine, a number of vitamins and microelements.

Fat must be fresh. Since fats are very easily oxidized. In overheated or stale fats, harmful substances accumulate, which lead to irritation of the gastrointestinal tract, kidneys, and disrupt metabolism. Such fats are strictly prohibited in the diet. The need for a healthy person in various fats is 80-100 g per day. In the diet, the quantitative and qualitative composition of fats can change. A reduced amount of fats, especially refractory ones, is recommended for atherosclerosis, pancreatitis, hepatitis, exacerbation of enterocolitis, diabetes, and obesity. And when the body is depleted after serious illnesses and with tuberculosis, it is recommended, on the contrary, to increase the intake of fat to 100-120 g per day.

Unsaturated fatty acids are monobasic compounds that have one (monounsaturated), two or more (polyunsaturated) double bonds between carbon atoms.

Their molecules are not completely saturated with hydrogen. They are found in all fats. The greatest amount of useful triglycerides is concentrated in nuts, vegetable oils (olive, sunflower, linseed, corn, cottonseed).

Unsaturated fats are a secret weapon in the fight against excess weight, if used correctly. They speed up metabolism, suppress appetite, the production of cortisol (stress hormone) against which overeating occurs. In addition, beneficial acids reduce leptin levels and block the gene responsible for the accumulation of fat cells.

General information

The most important property of unsaturated fatty acids is the ability to peroxide, due to the presence of double unsaturated bonds. This feature is necessary for the regulation of renewal, the permeability of cell membranes and the synthesis of prostaglandins, leukotrienes responsible for immune defense.

The most consumed mono- and polyunsaturated fatty acids:

• linolenic (omega-3);
• eicosapentaenoic (omega-3);
• docosahexaenoic (omega-3);
• arachidonic (omega-6);
• linoleic (omega-6);
• oleic (omega-9).

Useful triglycerides the human body does not produce on its own. Therefore, they must be present in the daily diet of a person without fail. These compounds are involved in fat, intramuscular metabolism, biochemical processes in cell membranes, are part of the myelin sheath and connective tissue.

Remember, the lack of unsaturated fatty acids causes dehydration, growth retardation in children, and inflammation of the skin.

Interestingly, omega-3, 6 form an indispensable fat-soluble vitamin F. It has a cardioprotective, antiarrhythmic effect, improves blood circulation, and prevents the development of atherosclerosis.

Types and role

Depending on the number of bonds, unsaturated fats are divided into monounsaturated (MUFA) and polyunsaturated (PUFA). Both types of acids are useful for the human cardiovascular system: they reduce the level of bad cholesterol. A distinctive feature of PUFAs is a liquid consistency, regardless of the ambient temperature, while MUFAs harden at +5 degrees Celsius.

Characteristics of beneficial triglycerides:

1. Monounsaturated. They have one double carbohydrate bond and lack two hydrogen atoms. Due to the inflection at the double bond point, monounsaturated fatty acids are difficult to condense, retaining a liquid state at room temperature. Despite this, they, like saturated triglycerides, are stable: they are not subject to granulation over time and rapid rancidity, therefore they are used in the food industry. Most often, fats of this type are represented by oleic acid (omega-3), which is found in nuts, olive oil, and avocados. MUFAs support the health of the heart and blood vessels, inhibit the reproduction of cancer cells, and give elasticity to the skin.
2. Polyunsaturated. In the structure of such fats, there are two or more double bonds. There are two types of fatty acids most commonly found in foods: linoleic (omega-6) and linolenic (omega-3). The first has two double clutches, and the second has three. PUFAs are able to maintain fluidity even at negative temperatures (freezing), exhibit high chemical activity, quickly rancid, and therefore require careful use. Such fats cannot be heated.

Remember, omega-3.6 is the building block needed to form all the beneficial triglycerides in the body. They support the protective function of the body, increase brain function, fight inflammation, and prevent the growth of cancer cells. Natural sources of unsaturated compounds include: canola oil, soybeans, walnuts, linseed oil.

Unsaturated fatty acids improve blood flow and repair damaged DNA. They enhance the delivery of nutrients to the joints, ligaments, muscles, internal organs. These are powerful hepatoprotectors (protect the liver from damage).

Useful triglycerides dissolve cholesterol deposits in blood vessels, prevent the appearance of atherosclerosis, myocardial hypoxia, ventricular arrhythmias, blood clots. Provide cells with building material. Due to this, worn-out membranes are constantly updated, and the youth of the body is prolonged.

For human life, only fresh triglycerides, which are easily oxidized, provide value. Overheated fats have a detrimental effect on metabolism, the digestive tract, and kidneys, as they accumulate harmful substances. Such triglycerides should be absent from the diet.

With daily use of unsaturated fatty acids, you will forget about:

• fatigue and chronic fatigue;
• painful sensations in the joints;
• itching and dry skin;
• type 2 diabetes;
• depression;
• poor concentration;
• fragility of hair and nails;
• diseases of the cardiovascular system.

Unsaturated acids for skin

Preparations based on omega acids relieve small wrinkles, maintain the "youth" of the stratum corneum, accelerate the healing of the skin, restore the water balance of the dermis, and relieve acne.

Therefore, they are often included in ointments for burns, eczema and cosmetic products for the care of nails, hair, and face. Unsaturated fatty acids reduce inflammatory reactions in the body, increase the barrier function of the skin. The lack of useful triglycerides leads to compaction and drying of the upper layer of the dermis, blockage of the sebaceous glands, penetration of bacteria into the deepest layers of tissues and the formation of acne.

EFA, which are part of cosmetics:

• palmitoleic acid;
• eicosene;
• erucic;
• acetic acid;
• oleic;
• arachidonic;
• linoleic;
• linolenic;
• stearic;
• nylon.

Unsaturated triglycerides are chemically more active than saturated ones. The rate of acid oxidation depends on the number of double bonds: the more there are, the thinner the consistency of the substance and the faster the electron donation reaction proceeds. Unsaturated fats thin the lipid layer, which improves the penetration of water-soluble substances under the skin.

Signs of a lack of unsaturated acids in the human body:

• thinning of the hair fiber;
• dryness, roughness of the skin;
• baldness;
• development of eczema;
• dullness of the nail plates, frequent appearance of burrs.

The effect of omega acids on the body:

1. Oleic. Restores the barrier functions of the epidermis, retains moisture in the skin, activates lipid metabolism, slowing down peroxidation. The largest amount of oleic acid is concentrated in sesame oil (50%), rice bran (50%), coconut (8%). They are well absorbed into the dermis, do not leave greasy marks, enhance the penetration of active ingredients into the stratum corneum.
2. Palm. Restores the skin, gives elasticity to the "mature" dermis. Differs in high stability at storage. Oils that contain palmic acid do not burn through over time: palm (40%), cottonseed (24%), soybean (5%).
3. Linoleic. It has an anti-inflammatory effect, interferes with the metabolism of biologically active substances, facilitating their penetration and absorption in the layers of the epidermis. Linoleic acid prevents uncontrolled evaporation of moisture through the skin, the lack of which leads to overdrying and peeling of the stratum corneum. It protects tissues from the harmful effects of ultraviolet rays, relieves redness, improves local immunity, and strengthens the structure of cell membranes. The lack of omega-6 in the body causes inflammation and dryness of the skin, increases its sensitivity, leads to hair loss, eczema. Contained in rice oil (47%) and sesame (55%). Due to the fact that linoleic acid stops inflammation, it is indicated for atopic eczema.
4. Linolenic (Alpha and Gamma). It is a precursor to the synthesis of prostaglandins that regulate inflammatory responses in the human body. Unsaturated acid is part of the membranes of the epidermis, increases the level of prostaglandin E. With insufficient intake of the compound in the body, the skin becomes prone to inflammation, irritated, dry and flaky. The largest amount of linolenic acid is found in breast milk.

Cosmetics with linoleic and linolenic acids accelerate the restoration of the lipid barrier of the epidermis, strengthen the structure of membranes, and act as a component of immunomodulatory therapy: it reduces the development of inflammation and stops cell damage. For dry skin types, oils containing omega-3, 6 are recommended to be used externally and internally.

In sports

To maintain the health of an athlete, at least 10% of fats must be present in the menu, otherwise sports results worsen, morpho-functional disorders appear. The lack of triglycerides in the diet inhibits the anabolism of muscle tissue, reduces the production of testosterone, and undermines the immune system. Only in the presence of unsaturated fatty acids is it possible to absorb B vitamins, which are essential for a bodybuilder. In addition, triglycerides cover the increased energy costs of the body, maintain healthy joints, accelerate the recovery of muscle tissue after intense training and fight inflammation. PUFAs prevent oxidative processes and are involved in muscle growth.

Remember, a deficiency of healthy fats in the human body is accompanied by a slowdown in metabolism, the development of beriberi, problems with the heart, blood vessels, hepatic dystrophy, and malnutrition of brain cells.

The best sources of omega acids for athletes: fish oil, seafood, vegetable oils, fish.

Remember, too much doesn't mean good. An excess of triglycerides (over 40%) in the menu leads to the opposite effect: fat deposition, deterioration of anabolism, decreased immunity, and reproductive function. As a result, fatigue increases and performance decreases.

The rate of consumption of unsaturated fatty acids depends on the sport. For a gymnast, it is 10% of the total diet, fencers - up to 15%, martial artists - 20%.

Harm

Excessive consumption of triglycerides leads to:

• the development of arthritis, multiple sclerosis;
• premature aging;
• hormonal failure in women;
• accumulation of toxins in the body;
• increased load on the liver, pancreas;
• the formation of stones in the gallbladder;
• inflammation of intestinal diverticula, constipation;
• gout;
• appendicitis;
• diseases of the coronary vessels of the heart;
• breast cancer, prostate cancer;
• irritation of the gastrointestinal tract, the appearance of gastritis.

Under the influence of heat treatment, healthy fats polymerize and oxidize, decomposing into dimers, monomers, polymers. As a result, vitamins and phosphatides in them are destroyed, which reduces the nutritional value of the product (oil).

Daily rate

The body's need for unsaturated fatty acids depends on:

• labor activity;
• age;
• climate;
• immune status.

In medium climatic zones, the daily rate of fat consumption per person is 30% of the total calorie intake, in the northern regions this figure reaches 40%. For the elderly, the dose of triglycerides is reduced to 20%, and for heavy manual workers it increases to 35%.

The daily requirement for unsaturated fatty acids for a healthy adult is 20%. This is 50 - 80 grams per day.

After an illness, with exhaustion of the body, the rate is increased to 80 - 100 grams.

To maintain good health and maintain health, exclude fast food and fried foods from the menu. Instead of meat, give preference to fatty sea fish. Give up chocolate, store-bought confectionery in favor of nuts and grains. Take as a basis to start the morning with a dessert spoon of vegetable oil (olive or linseed) on an empty stomach.

To enhance the positive effect of omega acids on the body, it is recommended to simultaneously consume antioxidants, zinc, vitamin B6, D.

natural springs

List of foods that contain unsaturated fatty acids:

• avocado;
• unsalted nuts (pecan, walnut, Brazilian, cashew);
• seeds (sesame, sunflower, pumpkin);
• fatty fish (sardines, mackerel, salmon, tuna, herring);
• vegetable oils (camelin, olive, corn, linseed, walnut);
• cereals;
• black currant;
• corn;
• dried fruits.

The maximum amount of nutrients is concentrated in cold-pressed vegetable oils in their raw form. Heat treatment destroys beneficial compounds.

Conclusion

Unsaturated fatty acids are essential nutrients that the human body cannot synthesize on its own.

To maintain the vital activity of all organs and systems, it is important to include foods containing omega compounds in the daily diet.

Useful triglycerides control the composition of the blood, supply cells with energy, support the barrier functions of the epidermis and help shed extra pounds. However, you need to use EFAs wisely, as their nutritional value is unusually high. An excess of fat in the body leads to accumulation of toxins, increased cholesterol, blockage of blood vessels, and a lack of fat leads to apathy, deterioration of the skin condition, and a slowdown in metabolism.

Eat in moderation and stay healthy!

Or an anti-cholesterol vitamin. They are divided into monounsaturated (omega-9) and polyunsaturated fatty acids (omega-6 and omega-3). At the beginning of the 20th century, much attention was paid to the study of these acids. Interestingly, vitamin F got its name from the word "fat", which means "fat" in English.

Despite the fact that fatty acids are called a vitamin, from the point of view of pharmacology and biochemistry, these are completely different biological compounds. These substances have a paravitamin effect, that is, they help the body fight beriberi. They also have a parahormonal effect due to the fact that they are able to turn into prostaglandins, thromboxanes, leukotrienes and other substances that affect the human hormonal background.

Benefits of unsaturated fatty acids

A special role among unsaturated fatty acids is occupied by linolenic type acids. they are indispensable for the body. Gradually, the human body loses the ability to produce gamma-linolenic acid by consuming linolenic acid with plant foods. Therefore, food, which includes this acid, you need to consume more and more. Also a good way to obtain this substance are biologically active additives (BAA).

Gamma-linolenic acid belongs to the group of omega-6 fatty acids. It plays an important role in the functioning of the body as it is part of cell membranes. If this acid is not enough in the body, then there is a violation of the metabolism of fats in tissues and the functioning of intercellular membranes, which leads to such diseases as liver damage, dermatosis, atherosclerosis of blood vessels, etc.

Unsaturated fatty acids are essential for humans, as they are involved in the synthesis of fats, cholesterol metabolism, the formation of prostaglandins, have an anti-inflammatory and antihistamine effect, stimulate the body's immune defenses, and promote wound healing. If these substances act with a sufficient content of vitamin D, then they also participate in the assimilation of phosphorus and calcium, which is necessary for the normal functioning of the skeletal system.

Linoleic acid is also important because if it is present in the body, the other two can be synthesized. You need to know that the more a person consumes carbohydrates, the more he needs foods containing unsaturated fatty acids. They accumulate in the body in certain organs - the heart, kidneys, liver, brain, muscles and blood. Linoleic and linolenic acids also affect the level of cholesterol in the blood, preventing it from settling on the walls of blood vessels. Therefore, with a normal content in the body of these acids, the risk of diseases of the cardiovascular system is reduced.

Lack of unsaturated fatty acids in the body

Most often, vitamin F deficiency occurs in young children.- under the age of 1 year. This happens when there is insufficient intake of acids from food, a violation of the absorption process, some infectious diseases, etc. This can result in stunting, weight loss, flaky skin, thickening of the epidermis, loose stools, and increased water intake. But there may be a lack of unsaturated fatty acids in adulthood. In this case, suppression of reproductive functions, the appearance of infectious or cardiovascular diseases can occur. Also often symptoms are brittle nails, hair, acne and skin diseases (most often eczema).

Unsaturated fatty acids in cosmetology

Since unsaturated fatty acids have a beneficial effect on the skin and hair, it is often used in the manufacture of various cosmetics. Such products help maintain the youthfulness of the skin and get rid of fine wrinkles. Also, preparations with vitamin F contribute to the restoration and healing of the skin, so they are used to treat eczema, dermatitis, burns, etc. With the help of a sufficient content of unsaturated fatty acids in the body, the skin effectively retains moisture. And with desiccated skin, normal water balance is restored.

Researchers have also shown that these acids help with acne. With a lack of vitamin F in the body, the upper layer of skin tissues thickens, which leads to blockage of the sebaceous glands and inflammatory processes. In addition, the barrier functions of the skin are disrupted, and various bacteria easily penetrate into the deeper layers. That is why today cosmetic preparations with vitamin F are becoming more and more popular. With these substances, products are made to care not only for the skin of the face, but also for hair and nails.

Excess unsaturated fatty acids

No matter how useful unsaturated fatty acids, but it is also not worth abusing products containing them in large quantities. These substances are non-toxic and non-toxic. However, with an increased content of omega-3 acids in the body, blood thinning occurs, which can lead to bleeding.

Symptoms of excess vitamin F in the body can be stomach pain, heartburn, skin-allergic rashes, etc. It is also important to know that unsaturated acids should be consumed in certain proportions. For example, with an excess of omega-6, there is a violation of the production of omega-3 acid, which can lead to the development of asthma and arthritis.

Sources of unsaturated fatty acids

The best sources of unsaturated fatty acids are vegetable oils.. However, ordinary refined sunflower oil is unlikely to bring much benefit. Wheat ovary, safflower, sunflower, flaxseed, olives, peanuts, and soybeans are best eaten. Other plant foods are also suitable - avocados, almonds, corn, nuts, brown rice and oatmeal.

In order to always have a sufficient amount of unsaturated fatty acids in the body, it is enough to eat, for example, about 12 teaspoons of sunflower oil (unrefined) per day. In general, all oils must be chosen carefully. They should not be filtered or deodorized. It is also important to know that when exposed to air, light, or heat, some acids can form free radicals and toxic oxides. Therefore, they must be stored in a dark, cool place in a tightly closed container. With the additional use of vitamins B6 and C, the effect of the action unsaturated fatty acids intensifies.

Fats are such macronutrients that are needed for a good nutrition of people. Each person's diet should include a variety of fats, each of which plays a role. They are part of all cells of the body and are necessary for the absorption of certain vitamins, ensuring thermoregulation, normal functioning of the human nervous and immune systems. There are saturated and unsaturated fatty acids in our body, and if the latter bring great benefits, the former are considered to be harmful. But is it really so, what role do saturated fats play in our body? We will consider this question today.

NLC - what is it?

Before considering the role of saturated fatty acids (SFAs), we learn what they are. EFAs are solids that melt at high temperatures. They are most often absorbed by the human body without the participation of bile acids, therefore they have a high nutritional value. But excess saturated fat is always stored in the body in reserve. EFAs give the fats they contain a pleasant taste. They also contain lecithin, vitamins A and D, cholesterol, saturate cells with energy.

For the past thirty years, it has been generally accepted that the content of saturated fatty acids in the body causes great harm to it, as it contributes to the development of diseases of the cardiovascular system. Thanks to new scientific discoveries, it became clear that they do not pose a danger, on the contrary, they have a good effect on the activity of internal organs. They also take part in thermoregulation, improve the condition of hair and skin. Even cholesterol is vital for the human body, as it takes part in the synthesis of vitamin D and hormonal processes. With all this, the body should have moderate amounts of saturated fatty acids. Benefits and harms will be discussed below.

Benefits of EFA

Saturated (marginal) fats are needed by the human body in the amount of fifteen grams per day. If a person does not receive the required number of them, then the cells will receive them by synthesis from other food, which will lead to an unnecessary load on the internal organs. The main function of saturated fatty acids is to provide energy to the entire body. In addition, they take part in the synthesis of hormones, the formation of testosterone and estrogen, membrane cells, fat layer to protect internal organs, and also normalize the protective functions of the body.

Lack of saturated fatty acids in the body

Insufficient intake of EFAs in the body can adversely affect its development. So, quite often in this case there is a decrease in body weight, disruption of the hormonal and nervous systems, the condition of the skin and hair. Over time, women may become infertile.

Harm

Some EFAs of animal origin are directly associated with the occurrence of severe inflammatory diseases. The risk increases especially when acids enter the human body in large quantities. So, the use of large portions of fats can cause an acute inflammatory process, unpleasant sensations occur within a short period of time after eating. It is also possible to accumulate cholesterol in large quantities, which is dangerous for the cardiovascular system.

An excess of SFA in the body

Excessive intake of SFA can also adversely affect its development. In this case, there is an increase in blood pressure, disruption of the cardiovascular system, the appearance of kidney stones. Over time, excess weight accumulates, cardiovascular diseases develop, and cancerous tumors develop.

What should be consumed?

First of all, you need a balanced diet that will be saturated with fatty acids. Useful foods rich in SFAs - eggs, fish and organ meats - are most preferable. In the daily diet, fatty acids should be allocated no more than ten percent calories, that is, fifteen or twenty grams. The best option is considered to be the use of fats, which are part of products that have a large number of useful properties, such as seaweed, olives, nuts, fish and others.

Natural butter is considered a good choice; lard is recommended to be consumed in salted form in small quantities. Refined oils, as well as their substitutes, bring the least benefit. Unrefined oils cannot be heat treated. In addition, you need to remember that you can not store fats in the sun, in the open air and in the light.

Basic EFAs

1. Propionic acid (formula - CH3-CH2-COOH). It is formed during the metabolic breakdown of fatty acids having an odd number of carbon atoms, as well as some amino acids. In nature, it is found in oil. Since it prevents mold and some bacteria from growing, propionic acid, whose formula we already know, is often used as a preservative in the manufacture of foods that people consume. For example, in bakery production it is used in the form of sodium and calcium salts.
2. Butyric acid (formula CH3-(CH2)2-COOH). It is one of the most important, it is formed in the intestines in a natural way. This fatty acid contributes to the self-regulation of the intestine, and also supplies energy to the epithelial cells. It creates such an acidic environment in which conditions become unfavorable for the development of pathogenic microflora. Butyric acid, the formula of which we know, has an anti-inflammatory effect, helps to stop the development of cancer cells, and increases appetite. It also helps to stop metabolic disorders, increases local immunity.
3. Valeric acid (formula CH3-(CH2)3-COOH). It has a mild antispasmodic effect. Like oil, it activates the motility of the colon, affecting the nerve endings of the intestine and stimulating smooth muscle cells. Acid is formed as a result of the metabolism of microorganisms in the colon. Valeric acid, the formula of which was given above, occurs as a result of the activity of bacteria that make up the intestinal microflora.
4. Caproic acid (formula CH3-(CH2)4-COOH). In nature, this acid can be found in palm oil, animal fats. Especially a lot of it in butter. It has a detrimental effect on many pathogenic bacteria, even those that are resistant to antibodies. Caproic acid (the formula above) plays an important role for the human body. It has anti-allergic activity, improves liver function.

• severe diseases of the respiratory system;
• great physical activity;
• in the treatment of the digestive system;
• pregnancy and lactation;
• in the cold season, as well as people who live in the Far North;
• some diseases of the heart and blood vessels.

For quick assimilation, fats must be consumed with vegetables, herbs and herbs. It is best to use natural products that contain them, as well as having most of the useful components in their composition.

Sources of SFA

Most saturated fatty acids are found in foods that are of animal origin. It can be meat, fish, poultry, milk and cream, lard, beeswax. EFAs are also found in palm and coconut oils, cheeses, confectionery, eggs, and chocolate. People who lead a healthy lifestyle and watch their figure need to include saturated fats in their diet.

Summing up

Saturated and unsaturated fatty acids are the main sources of energy for the human body. They are important for the structure and development of cells and come from food of animal origin. Such fats have a solid consistency that does not change at room temperature. Lack and excess of them adversely affects the body.

In order to have good health, you need to consume about fifteen or twenty grams of saturated acids per day. This will replenish energy costs and not overload the body. Nutritionists recommend replacing harmful fatty acids found in fried meat, fast food, confectionery with dairy products, sea fish, nuts, and more.

It is necessary to constantly monitor not only the quantity, but also the quality of food consumed. Proper nutrition helps to improve well-being and health in general, increase productivity, and overcome depression. Thus, it is impossible to divide fats into “good” and “bad”, they all play an important role in the development and structure of the body of each of us. You just need to be more careful about the composition of your daily diet and remember that health problems arise due to a combination of factors, as well as a person’s lifestyle, so you should not be afraid of fats, both saturated and unsaturated.