What are fats? Definition, formula, classification, properties

The question of what fats are can be answered in one word - these are triglycerides. But it will not bring clarity to the topic. Like the explanation that triglycerides (or, as they are also called, triacylglycerides) are the products of the esterification of carboxylic acids and 3-atomic alcohol glycerol.

In simpler language, fats are the most important natural compounds found in the body of every living being, without exception. And therefore about them, as well as about everything related to this topic, it is necessary to tell in details.

what is fat


Just look at the above image to understand how it looks and what visually represents a combination of fats.

The formula is easy to understand. R1, R2 and R3 are radicals of the same or different acids. Oh, as everyone knows, it is oxygen, C is carbon, and H is hydrogen.

The composition of natural fats always contains three acid radicals with an unbranched structure. The number of carbon atoms is usually odd. The content of "even" is usually less than 0.1%.


The composition of fats was determined by the nineteenth-century French scientists named Michel Eugene Chevrel and Pierre Eugene Marcelain Berthelot.

Chemists did not work together. Chevrel in 1811 found out that if you heat a mixture of water and fat in an alkaline medium, then carboxylic acids (oleic and stearic, to be more precise) and glycerin are formed. And in 1854, Bertlo got the opposite reaction. He synthesized fat by heating a mixture of carboxylic acids and glycerin.

Also, due to such experimental studies, it was found out that triglycerides are hydrophobic. They are not soluble in water. But they are able to split other liquids. 5-10% ethanol can do this in part. And organic solvents - entirely.

fat application

Alkanoic acid

You can not ignore them, talking about what fats are. Alkanoic acids are derivatives of saturated carbons with one functional carboxyl group. The composition of natural fats, as a rule, includes:

  • Stearic alkanoic acid. C17H35COOH. It is odorless, soluble in ether, but not in water. It can be obtained by oxidation of saturated hydrocarbons with manganese compounds.It is a part of lipids (one of the components of tissues and cells of animal organisms) and glycerides.
  • Margarine alkanoic acid. C16H33COOH. In natural sources contained in low concentrations. In peanut butter, for example, it is only 0.2% of the sum of all other fatty acids.
  • Palmitic alkanoic acid. C15H11COOH. It is the most common monobasic saturated acid. In butter, for example, it contains 25%. In lard - 30%. Widely applicable in the manufacture of napalm, cosmetics and detergents, plasticizers and lubricating oils.
  • Kapron alkanoic acid. C5H11COOH. It is contained in Babassu palm oil, in some wood, also formed during the fermentation of sugar with the participation of rotten cheese. Used to produce esters, which are used as flavors.
  • Oily alkanoic acid. C5H7COOH. The most important low molecular weight acid synthesized in the intestine. Element supporting homeostasis in the body. It shows anti-inflammatory and anti-cancer effects, affects appetite.

Alkanoic acids in fats most. Least of all - carboxylic.However, this is not the full range of acids that make up their composition. But about it - further.

Alkene acids

These are chemically active elements that easily enter into oxidation reactions and hydrogenate with hydrogen or strong reducing agents to alkanes. The composition of natural fats includes only two alkene acids:

  • Palmitoleic. C15H29COOH. Monounsaturated. That it is one of the components of human subcutaneous fat (about 3-5% by weight of other acids). It is also in rapeseed, sesame, safflower, olive oil. Partially synthesized from carbohydrates. The use of fats of this class is necessary - the rate of an adult person is 10% of the caloric content of his daily diet.
  • Olein. C17H33COOH. The alkali metal salts of this acid are widely used in the textile industry. Its esters, like herself, are applicable in the manufacture of paints and varnishes, in the process of soap making, in the production of sizing and cosmetics. It is found in large quantities in many fats - beef, pork, cod, oil of papaya, almond, camellia, olive, pistachio, etc.

 getting fat

Other acids

Continuing the theme of chemistry "Fats", it is worth noting that they also include one type of alkadienic (hydrocarbon) acids. Linoleic, to be precise (C17H31COOH).It is widely distributed in vegetable oils. It is an indispensable fatty acid necessary for proper life. In the body comes from food.

And the last type of acids related to the composition of natural fats is alkatrienic. From this class one should distinguish linolenic acid (not to be confused with the one mentioned above) and arachidonic.

What are they? Linolenic acid is synthesized from linoleic. In large quantities found in algae and in the leaves of green plants. Also indispensable. But arachidonic acid is synthesized by the human body independently from linoleic acid. In the composition of lipids, it is present in milk fat, in the liver and brain.

Animal fats

Now you can go to the classification. The chemistry of fats, as it was already possible to understand on the basis of their composition, is rather complicated. But nevertheless, everyone knows that these substances are divided into animal and vegetable by origin.

Fats of the first type are extracted from the connective tissues - bone and fat. They are also found in milk, eggs, in some reptiles, in fish, poultry and meat of mammals.It is important to note that animal fats also have their own classification. They are divided by:

  • Types of animals. There are fats of marine and freshwater fish, reptiles and amphibians, terrestrial and mammals.
  • Kinds of animals. There are pork fat, mutton, beef, chicken, mink, whale, etc.
  • The source of receipt. Fat can be liver, bone, interior, subcutaneous.
  • Consistency. There are liquid, soft and hard fats.
  • Variety. There are only four of them - the third, the second, the first and the highest.
  • Quality. There are technical fat, crude, refined, refined and deeply cleaned.
  • Purpose. There are technical, cosmetic, medical, feed and edible fats.
  • The method of obtaining. There is an acid fat, alkaline, extraction, vibroextraction, evaporation, separation, as well as obtained by the process of dry or wet heating.

What is the raw material from which it is extracted? Usually these are bones, skin ridges, skins, omentum, fat, fatty cutting, stomachs, intestines, internal organs, etc.

fat formula

Vegetable fats

About them, too, should say a few words. Fats in plants are contained in relatively small quantities.The exceptions are oilseeds. Such plants as soybean, rapeseed, sunflower, european olive, coconut palm, cotton, peanuts, etc. are meant. Their seeds may contain more than 50% of fat. And it is good for production.

Oil extraction

Getting fats from this raw material is not an easy process. Initially, seeds are thoroughly cleaned and processed. They need to get rid of husk, dirt. And some even blow through the air in order to get rid of unnecessary impurities. Then the seeds are dried and after a while they are pressed - and so it is possible to remove vegetable fats from the raw materials. Only then they go through the final stage (filtration and sometimes heat treatment) and go on sale.

 medical fats


A few words should be said about them. The following chemical properties of fats are distinguished:

  • Saponification The triglycerides of the previously listed acids have the ability to transform, which is characteristic of esters. Their bonds are broken down by caustic alkalis. The result - the formation of alkaline salts of fatty acids and free glycerol.
  • Rancid This property of fats is manifested when they are stored in adverse conditions - in warm, in the light, in places with high moisture and free access to air.Under the influence of these factors, fats begin to smell foul and acquire a bitter taste.
  • Drying. Most fats are by definition fluid. But some of them, being deposited on something with a thin layer, remain as such, while others oxidize and turn into a resin-like film. Such fats are called drying. And the ability of certain oils to dry is used in the national economy (in the paint industry, for example).

But this is all generalized. Above it was said a lot about what fats are, so on the basis of such detailed information we can conclude that their specific properties are determined by the qualitative composition, quantitative ratio, percentage of acids, as well as many other factors.

fat properties


We all eat fats in one way or another. Almost all products and dishes contain a certain proportion of them. It is logical, because what is fat? This is one of the components of our body. Fat is a certain percentage of the human body mass. For men, the minimum figure is 9-22%, for women - 15-25%.

So getting fat from food is a must.This substance is one of the main sources of energy for us. It has twice the energy value than carbohydrates. In addition, it is fats, deposited in the subcutaneous tissue, perform the function of a heat insulator that protects the body from heat loss. A good example is seals and whales.

Saturated Fat

The main source of energy can cause undoubted harm to the body. If it is saturated fats. They are solid, of animal origin and poorly digested. If you use too many products with their content, they will form visceral deposits in the body. And they, like cotton wool, envelop the internal organs.

The consequences are terrible - strokes, heart attacks, atherosclerosis, obesity, hepatosis, cirrhosis of the liver and a number of intractable diseases and ailments.

chemical properties of fats

Lipid Therapy

Finally, I would like to touch on this topic. Lipid therapy is aimed at not quite standard and habitual use of fats. For healing purposes, to be precise.

Healing fats are used externally - to prevent skin diseases, improve the condition of the integument, heal wounds, ulcers and burns.They are also used for massage, compresses, baths and even inhalations.

  • Lamb fat is often used as an ointment base. It accelerates the absorption of healing substances from ointments.
  • Badger fat is taken orally for tuberculosis, pneumonia and bronchitis. It is considered an excellent preventive measure.
  • Goose fat helps to get rid of pain in the hips, with cracks in the legs and arms. They are also good to lubricate frostbitten places.
  • Snake oil is used for compresses. It is also rubbed with pain of a different nature. And he effectively pulls old fragments and relieves muscle pain.
  • Goat fat is common in traditional medicine, as the basis for the manufacture of ointments. And with an intestinal ulcer do with it an enema.
  • Pig fat is considered beneficial in tumors, ulcers of the intestines and stomach.
  • Bear helps to remove purulent crusts from wounds, heals motionless joints, sore bones and muscles. Take inward to eliminate leprosy and discomfort in the anus. It is rubbed into the scalp - it helps with hair loss.
  • Fish oil has a great effect on the immune system, reducing the risk of developing many diseases.It also helps to alleviate the effects of chemical and thermal burns.
  • And finally fat groundhog. The rarest. They rubbed the chest and back with colds.

As you can see, the use of fats is very extensive. And if you believe the people who use them, then they have an amazing effect.

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