Spine 

It contains organic acids and. Organic acids, their varieties

Found in pure form in plants, as well as in the form of salts or esters - organic compounds

In a free state, such polybasic hydroxy acids are found quite often in fruits, while compounds are characteristic primarily of other plant elements such as stems, leaves, and so on. If you look at organic acids, their list is constantly growing and, in general, is not closed, that is, it is regularly replenished. Acids such as:

Adipic,

Benzoin,

Dichloroacetic,

Valerian,

Glycolic,

Glutaric,

Lemon,

Maleic,

Margarine,

Oil,

Dairy,

Monochloroacetic,

Formic,

Propionic,

Salicylic,

Trifluoroacetic,

Fumaric,

Acetic,

Sorrel,

Apple,

Succinic and many other organic acids.

Such substances can often be found in fruit and berry plants. Fruit plants include apricots, quince, cherry plum, grapes, cherries, pears, citrus fruits and apples, while lingonberries, cherries, blackberries, cranberries, gooseberries, raspberries, and black currants are considered berry plants. They are based on tartaric, citric, salicylic, oxalic and organic acids are also present in berries, including many

To date, many properties of acids have been studied directly in the field of pharmacology and biological effects on the human body. For example:

  • firstly, organic acids are quite significant components of metabolism (metabolism, namely proteins, fats and carbohydrates);
  • secondly, they cause the secretory work of the salivary glands; promote acid-base balance;
  • thirdly, they take a significant part in increasing the separation of bile, gastric and pancreatic juices;
  • and finally, they are antiseptics.

Their acidity ranges from four points to five and five.

In addition, organic acids play an important role in the food industry, acting as a direct indicator of the quality or poor quality of products. For the latter, the method of ion chromatography is very often used, in which not only organic acids, but also inorganic ions can be detected at a time. With this method, conductometric detection with background conductivity damping shows a result that is almost ten times more accurate than detection at low wavelengths of ultraviolet radiation.
Revealing the profile of organic acids in fruit juices is necessary not only to establish the quality of the drink, its admissibility for consumption, but also contributes to the determination of counterfeiting.
If we consider directly the properties of carboxylic acids, then they primarily include:

Giving red color to litmus paper;

Easy solubility in water;

Sour taste present.

They are also quite an important electrical conductor. According to the strength of decomposition, absolutely all acids belong to the weak group of electrolytes, with the exception, of course, of formic acid, which in turn occupies an average intensity value. The molecular weight height of a carboxylic acid affects the strength of decomposition and is inversely proportional. With the help of specifically defined metals, it becomes possible to separate hydrogen and salt from acids, which occurs much more slowly than when interacting with such as sulfuric or hydrochloric. Salts also appear when exposed to basic oxides and bases.

Organic acids, as you might guess, are organic substances with acidic properties. They include carboxylic acids, sulfonic acids, and some others. Carboxylic acids contain a carboxyl group -COOH, and sulfonic acids contain a sulfo group with the general formula SO 3 H.

Carboxylic acids

Carboxylic acids are derivatives of hydrocarbons, in the molecules of which one or more carbon atoms form a carboxyl group. Carboxylic acids are classified by basicity (number of carboxyl groups) and by the type of radical:

  • Monobasic saturated acids... The first member of the homologous series is formic acid HCOOH, then acetic (ethanoic) acid CH 3 COOH. In nature, higher fatty acids are found in fats. Of these, stearic acid C 17 H3 35 COOH is the most important.
  • Dibasic saturated acids... The simplest of these acids is oxalic (another name is ethanedioic) acid HOOC-COOH, which is formed in some plants (sorrel, rhubarb).

DEFINITION

Acid - electrolytes, during the dissociation of which only H + ions are formed from positive ions:

HNO 3 ↔ H + + NO 3 -

CH 3 COOH↔ H + + CH 3 COO -

Classification of acids

Acids are primarily classified into inorganic and organic (carboxylic). Organic compounds such as alcohols and phenols exhibit weak acidic properties. Inorganic and carboxylic acids, in turn, have their own classifications. So, all inorganic acids can be classified:

  • by the number of hydrogen atoms capable of elimination in an aqueous solution (monobasic –HCl, HNO 2, dibasic –H 2 SO 4, H 2 SiO 3, tribasic –H 3 PO 4)
  • acid composition (oxygen-free - HI, HF, H 2 S and oxygen-containing - HNO 3, H 2 CO 3)

Carboxylic acids are classified:

  • by the number of carboxyl groups (monobasic - HCOOH, CH 3 COOH and dibasic –H 2 C 2 O 4)

Physical properties of acids

Under n.u. most inorganic acids exist in a liquid state, some in a solid state (H 3 PO 4, H 3 BO 3).

Organic acids with the number of carbon atoms up to 3 are easily mobile, colorless liquids with a characteristic pungent odor; acids with 4-9 carbon atoms are oily liquids with an unpleasant odor, and acids with a large number of carbon atoms are solids that are insoluble in water.

Carboxyl group structure

DEFINITION

Carboxyl group - -COOH consists of a carbonyl group -\u003e С \u003d O and a hydroxyl group –OH, which mutually influence each other. The lone pair of electrons of the oxygen atom in the hydroxide ion is displaced towards the carbon atom of the carbonyl group, which weakens the –OH bond and determines the presence of acidic properties (Fig. 1).

Fig. 1 The structure of the carboxyl group

Getting acids

Inorganic and organic acids are prepared in different ways. So, inorganic acids can be obtained:

  • by the reaction of acid oxides with water

    SO 3 + H 2 O \u003d H 2 SO 4

  • by the reaction of combining non-metals with hydrogen

    H 2 + S ↔ H 2 S

  • by the exchange reaction between salts and other acids

    K 2 SiO 3 + 2HCl → H 2 SiO 3 ↓ + 2KCl

Organic acids are obtained by:

  • oxidation of aldehydes and primary alcohols (KMnO 4 and K 2 Cr 2 O 7 act as oxidants)

    R - CH 2 –OH → R –C (O) H → R-COOH,

    where R is a hydrocarbon radical.

Chemical properties of acids

The general chemical properties of both organic and inorganic acids include:

- the ability to change the color of indicators, for example, litmus becomes red when it gets into a solution (this is due to the dissociation of acids);

- interaction with active metals

2RCOOH + Mg \u003d (RCOO) 2 Mg + H 2

Fe + H 2 SO 4 (p - p) \u003d FeSO 4 + H 2

- interaction with basic and amphoteric oxides

2RCOOH + CaO \u003d (RCOO) 2 Ca + H 2 O

6RCOOH + Al 2 O 3 \u003d 2 (RCOO) 3 Al + 3H 2 O

2HCl + FeO \u003d FeCl 2 + H 2 O

6HNO 3 + Al 2 O 3 \u003d 2Al (NO 3) 3 + 3H 2 O

- interaction with bases

RCOOH + NaOH \u003d RCOONa + H 2 O

H 2 SO 4 + 2NaOH \u003d Na 2 SO 4 + H 2 O

- interaction with salts of weak acids

RCOOH + NaHCO 3 \u003d RCOONa + H 2 O + CO 2

CH 3 COONa + HCl \u003d CH 3 COOH + NaCl

Specific properties of inorganic acids

The specific properties of inorganic acids include redox reactions associated with the properties of acid anions:

H 2 SO 3 + Cl 2 + H 2 O \u003d H 2 SO 4 + 2HCl

Pb + 4HNO 3 (conc) \u003d Pb (NO 3) 2 + 2NO 2 + 2H 2 O

Specific properties of organic acids

The specific properties of organic acids include the formation of functional derivatives by substitution of the hydroxyl group (1, 2, 3, 4), as well as halogenation (5), reduction (6), and decarboxylation (7).

R –C (O) -OH + PCl 5 \u003d R –C (O) -Cl (acid chloride) + POCl 3 + HCl (1)

R –C (O) -OH + H-O-C (O) -R \u003d R - C (O) - O - C (O) - R (anhydride) (2)

CH 3 COOH + CH 3 -CH 2 -OH \u003d CH 3 -C (O) -O-C 2 H 5 (ethyl acetate (ester)) + H 2 O (3)

CH 3 COOH + СH 3 –NH 2 \u003d CH 3 -C (O) -NH-CH 3 (amide) + H 2 O (4)

CH 3 –CH 2 -COOH + Br 2 \u003d CH 3 - CHBr –COOH + HBr (catalyst - P cr) (5)

R-COOH + LiAlH 4 (aqueous solution acidified with HCl) \u003d R-CH 2 -OH + AlCl 3 + LiCl (6)

CH 2 \u003d CH-CH 2 -COOH \u003d CO 2 + CH 2 \u003d CH-CH 3 (7)

Examples of problem solving

EXAMPLE 1

The task Write the reaction equations as follows:

Decision 1) 3C 2 H 5 OH + 4Na 2 CrO 4 + 7NaOH + 4H 2 O \u003d 3CH 3 COONa + 4Na 3

2) СН 3 СООС 2 Н 5 + NaOH \u003d CH 3 COONa + С 2 Н 5 ОН

3) 5C 2 H 5 OH + 4KMnO 4 + 6H 2 SO 4 \u003d 5CH 3 COOH + 2K 2 SO 4 + 4MnSO 4 + 11H 2 O

4) CH 3 COONa + C 2 H 5 I \u003d CH 3 COOS 2 H 5 + Nal

5) CH 3 COONa + HCl \u003d CH 3 COOH + NaCl

6) CH 3 COOH + C 2 H 5 OH CH 3 COOS 2 H 5 + H 2 O (Exposure to H 2 SO 4)

EXAMPLE 2

The task Determine the mass of pyrite (FeS2) required to obtain such an amount of SO3 so that when the latter is dissolved in a solution of sulfuric acid with a mass fraction of 91% and a mass of 500 g, oleum with a mass fraction of 12.5% \u200b\u200bis obtained.
Decision Let's write down the reaction equations:

1) 4FeS 2 + 11O 2 \u003d 2Fe 2 O 3 + 8SO 2

2) 2SO 2 + O 2 \u003d 2SO 3

3) SO 3 + H 2 O \u003d H 2 SO 4

Let's find the molar masses of the substances required for further calculations:

M (H 2 O) \u003d 18 g / mol; M (SO 3) \u003d 80 g / mol; M (H 2 SO 4) \u003d 98 g / mol; M (FeS 2) \u003d 120 g / mol

The mass of water in 100 g of sulfuric acid solution (ω \u003d 91%) will be:

100 - 91 \u003d 9.0 g

v (H 2 O) \u003d 9/18 \u003d 0.5 mol

From the reaction equation (3) it follows that

1 mol SO 3 → 1 mol H 2 O → 1 mol H 2 SO 4, i.e.

0.5 mol H 2 O will react with 0.5 mol SO 3 and 0.5 mol H 2 SO 4 is formed

Calculate the mass of SO 3

m (SO 3) \u003d 0.5 80 \u003d 40 g

Calculate the mass of H 2 SO 4

m (H 2 SO 4) \u003d 0.5 98 \u003d 49 g

Then the total mass of H2SO4 will be

m (H 2 SO 4) sum \u003d 91 + 49 \u003d 140 g

To obtain oleum (ω \u003d 12.5%) for 140 g of H 2 SO 4, SO 3 is required:

m (SO 3) \u003d 12.5 140 / 87.5 \u003d 20 g

Thus, total SO 3 is consumed

m (SO 3) sum \u003d (40 + 20) \u003d 60 g

v (SO 3) sum \u003d 60/80 \u003d 0.75 mol

It follows from the reaction equations (2, 3) that the formation of 0.75 mol of SO 3 requires

v (FeS 2) \u003d 0.75 / 2 \u003d 0.375 mol

m (FeS 2) \u003d 0.375 120 \u003d 45 g
Answer Pyrite mass 45 g.

Organic acids are indispensable components of the chemical composition of plant materials. They are found in all tissues and organs of plants: for storage organs - fruits, rhizomes, etc. - the predominance of free organic acids is characteristic, in vegetative organs - grass, buds, leaves - they are found, as a rule, in the form of acidic salts.

Acids play an extremely important role in the metabolism of a plant cell: being mainly products of the conversion of sugars, they participate in the synthesis of amino acids, alkaloids and many other compounds. A number of plants have the ability to synthesize and accumulate organic acids and can serve as raw materials for their industrial production.

The list of organic acids that make up plant materials is quite wide, while the most common are acetic acid, which participates in the metabolism of all plants without exception in the form of acetyl CoA, as well as malic, citric, oxalic and succinic acids, which are the primary products of photosynthesis and are involved in the metabolism of plant cells.

Apple acid (COOH – CH 2 –CH (OH) –COOH)) is the most labile, it participates in the processes of photosynthesis, undergoing rapid changes and being an intermediate product in the biosynthesis of many compounds. This acid is known in three stereoisomeric forms, but only the L isomer is found in plants.

Malic acid is predominant in apples (0.4 ... 0.7 g / 100 g product), most types of stone fruits; it is rich in red-fruited mountain ash, garden strawberries (1.2 g / 100 g), cranberries and gooseberries (1.0 g / 100 g), raspberries (1.4 g / 100 g) and sea buckthorn (2.0 g / 100 g) ), green grapes (0.7 ... 1.5 g / 100 g), a fairly high content is noted in plums (3.5% of the dry matter) and barberry berries (up to
6% of the dry matter), the presence of malic acid was revealed in the composition of the acids of quince (0.5 g / 100 g) and peaches (0.2 g / 100 g), citrus fruits, rose hips, lemongrass and blueberries, flowers of calendula.

As malates malic acid accumulates in the leaves of coltsfoot, black currant and plantain (in the latter 0.2 ... 0.5%), horsetail grass and other raw materials; especially significant in the leaves of this. Tolstyankovs. Free acid and its salts are also included in the accompanying substances of FAS in most types of raw materials harvested by rhizomes and roots.

Using the example of grapes, it is shown that plants growing in the northern regions accumulate more malic acid than the same crops grown to the south. This fact is explained by the fact that at higher average daily temperatures, malic acid in fruits and green mass of plants is consumed for oxidation faster than tartaric acid, as a result of which its share in the composition of acids decreases.

Lemon acidand her salts citrates:

Found in plant raw materials no less often. They are the richest in citrus fruits (lemon - 5.5 ... 5.7 g / 100 g), of which citric acid was mainly isolated on an industrial scale until 1922; pomegranates, currant berries (2.0 ... 10.0 g / 100 g), lemongrass, raspberries, cranberries (1.1 ... 3.0 g / 100 g), a smaller amount of citric acid is contained in gooseberry berries (0.3 g / 100 g) and strawberries (0.1 g / 100 g), quince (0.3 g / 100 g), peaches (0.1 ... 0.2 g / 100 g) and apples (0.1 g / 100 g), rose hips, red-fruited mountain ash and hawthorn; from herbaceous raw materials, citric acid has been identified in the leaves of bilberry, black currant, celandine, plantain (1.2 ... 1.5%) and some others.

Oxalic acid (HOOC – COOH) is one of the by-products of the life of a plant cell, therefore it is chemically the least active and accumulates in plant raw materials mainly in the form of calcium salt ( oxalates - crystals of various forms specific to the plant species; this feature is used to identify medicinal and technical raw materials), accumulating mainly in juicy herbaceous raw materials: leaves of sorrel (calcium oxalate 0.56 ... 0.93 g / 100 g) and rhubarb (2.37 g / 100 g), horsetail herb, succulent scales of bulbous plants, tree bark, etc. Fruit and berry products are not rich in oxalic acid (up to 0.01 ... 0.02 g / 100 g), insignificant amounts are found in Schisandra berries (0.06 g / 100 g) and berries of this family. Lingonberry.

Physiologically significant content succinic acid (HOOC – CH 2 –CH 2 –COOH) is characteristic of gooseberries, lemongrass, red currants, blueberries and grasslands, rhubarb stalks. In sufficiently high amounts (0.01 ... 0.02 g / 100 g), this acid and its salts succinates found in unripe fruits and berries, such as cherries, cherries, plums, apples, grapes. Among other types of raw materials, in the acid complex of which free succinic acid and its salts are isolated, it is possible to note hawthorn berries, rhizomes and roots of rhodiola, plantain leaves (0.2 ... 0.5%), bitter wormwood, belladonna, poppy, corn.



Less commonly found in plant materials wine acid(COOH – CH (OH) –CH (OH) –COOH, D-isomer): in berries (green - 0.8 ... 1.3 g / 100 g, ripe - from 0.2 to 1.0 g / 100 d), stems and leaves of grapes (up to 3.7% on dry weight), red-fruited mountain ash, hawthorn, plum and pomegranate fruits; berries of raspberry, gooseberry, currant, lemongrass and lingonberry. Along with D-acid, grapes contain pyruvic acid (traces) and an inactive DL-isomer of tartaric acid - grape acid. In addition to the named types of raw materials, tartaric acid is a part of the acids of the leaves of lingonberry, coltsfoot, plantain, etc.

Not only the taste of plant raw materials depends on the content and composition of organic acids, but to some extent also its aromatic properties, which is determined by the presence of free formic, acetic, propionic, butyric, caprylic and valeric acids and their esters in the volatile fraction. These acids cause specific aroma shades of medicinal and technical raw materials, mainly ether-bearing plants, they all have a sharp, pungent odor. So, formic acid (HCOOH) is a part of organic acids of apples, bearberry, viburnum, juniper cone berries, raspberries (1.76 mg / 100 g), stalks and leaves of nettles, yarrow herb and many other raw materials; in a free state, it is more often found in green leaves; it is believed that it belongs to the intermediate products of photosynthesis. Acetic acid (CH 3 –COOH), both in the free state and in the composition of esters with alcohols, participates in the formation of the flavor characteristics of the same viburnum and juniper, lingonberry berries
(traces), peppermint leaves, wormwood herb and forest land-
nicks, yarrow, rhizomes and roots of valerian, elecampane and
angelica, etc. Availability valerian and / or isovaleric acid ((CH 3) 2 CH – CH 2 –COOH) was established for mint and laurel leaves, hyssop herb, wormwood and yarrow, wild strawberries, viburnum fruits, peaches and cocoa fruits, rhizomes and roots of valerian and angelica. The chemical composition of valerian, in addition to the already mentioned organic acids, includes oil(CH 3 –CH 2 –CH 2 –COOH); Butyric acid is also a part of chamomile flowers.

Caprylic aciddetermines the aroma of peaches:

Propionic acid (CH 3 –CH 2 –COOH) from the whole variety of plant materials is found only in the flower baskets of yarrow. As can be seen from the above, for many types of plant raw materials - sources of essential oils - the presence of all volatile acids is characteristic at once.

Esters of organic acids determine the characteristic aroma of plant raw materials: octyl acetate - orange, methylbutyrate - apricot, isoamyl ether of isovaleric acid - apples, sebacin acetate - pine cone of juniper, borneol ether with valeric acid - rhizomes and roots of valerian officinalis, etc.

Some of the organic acids are found in the harvested raw material much less frequently, in some cases being of particular interest as an identification feature. These acids include angelic - rhizomes and roots of angelica; aconite (COOH – CH \u003d C (COOH) –CH 2 –COOH) - grass of horsetail, delphinium, adonis and yarrow; malonic (COOH – СH 2 –COOH) - plantain leaf, maple sap, plant tissues of this family. Legumes; fumaric (COOH – CH \u003d CH – COOH), which is considered genetically related to succinic and malic acids and from among higher plants, revealed only in the composition of plants of the family. Macophytes, in berries
barberry, cranberry and erika gray, quince fruits; sorbin
(CH 3 –CH \u003d CH – CH \u003d CH – COOH), undoubtedly associated with alcohol, sorbitol and found in the berries of the red-fruited mountain ash, lingonberry; DL-milk (CH 3 –CH (OH) –COOH) - raspberry and agave leaves, blueberries and cumanberries; glyoxalic(CHO – COOH) - green leaves and unripe grapes, cranberries, dogwood fruits
etc.

It is especially necessary to say about keto acids, which are a link in the metabolism of carbohydrates and proteins and have a high physiological activity. For plants, the accumulation of keto acids in significant amounts is not typical, the total content pyruvic (CH 3 –CO – OOH), α -ketoglutaric (COOH – CH 2 –CH 2 –CO – COOH), oxaloacetic (COOH – CH 2 –CO – COOH) and sorrel amber (COOH – CH 2 –CH (COOH) –CO – COOH) acids usually does not exceed several mg per 100 g of raw material. The maximum content of keto acids was found in the leaves and berries of lingonberry (0.13 mg / 100 g of pyruvic; 0.22 mg / 100 g of α-ketoglutaric; 0.025 mg / 100 g of oxaloacetic), strawberry leaves (0.87 mg / 100 g of pyruvic; 28.4 mg / 100 g α-ketoglutaric; 0.65 mg / 100 g
oxaloacetic) and mint leaves (0.11 mg / 100 g of pyruvic and 1.9 mg / 100 g of ketoglutaric).

Cyclohexane series acids - cinchona (coffee, fruits of quince, irgi, plums and peaches, berries of actinidia, cranberries and blueberries, lingonberry leaves, etc.) and shikimovaya, found in the fruits of star anise and cranberries, are not only specific, but it is customary to separate them into a separate subgroup of PAS, as they play a particularly important role in the biosynthesis of aromatic amino acids (shikimic acid is a precursor of phenylalanine and tyrosine), cinnamic acids and some other substances.

Acids are involved in the formation of the individual taste of certain types of plant materials. Each acid has its own specific taste and sensation threshold: malic and citric acids have a pure, non-astringent taste; tartaric acid has a sour astringent taste; succinic acid has an unpleasant taste, etc. The intensity of the sour taste of raw materials is determined by the composition and quantitative ratio of individual acids, the ratio of free and bound acids, the composition of accompanying substances (sugars mask the sour taste, tannins enhance and make them astringent).

For an objective assessment of the taste of plant materials, the so-called sugar-acid coefficient was adopted, the calculation of which is based on the ratio of acids and sugars (taking into account the sweetness of the latter):

,

where is the glucose content,%;

- fructose content,%;

- sucrose content,%;

- acid content,%.

Acidity is expressed as a percentage of the dominant acid.

Physiologically, organic acids have a beneficial effect on digestion processes, lowering the pH of the environment and contributing to the creation of a certain composition of microflora, inhibiting the processes of decay in the gastrointestinal tract. Phenolic acids have a bactericidal effect. Assimilated organic acids are also involved in the formation of the energy value of food and drinks with their participation: malic acid - 2.4 kcal / g, citric acid - 2.5 kcal / g, lactic acid - 3.6 kcal / g, etc. Tartaric acid is not absorbed by the human body.

Some organic acids are involved in the mechanisms of metabolic processes responsible for body weight control (for example, hydroxycitric acid, which inhibits citrate lyase in the enzyme system for the synthesis of fatty acids) - this property is the basis for the development of dietary supplements from medicinal plant raw materials, the action of which is based on inhibition of synthesis fatty acids from carbohydrates de novo... Succinic acid improves the energy supply of the cells of the brain, myocardium, liver, kidneys; has an antioxidant and antihypoxic effect (the mechanism of action is associated with an increase in ATP synthesis, inhibition of glycolysis and activation of aerobic processes in cells, an increase in gluconeogenesis). In addition, succinic acid helps to stabilize cell membranes, which prevents the loss of enzymes and ensures the functioning of detoxification mechanisms in cells. Against the background of flavonoids and saponins (licorice, for example), succinic acid exhibits anti-inflammatory, detoxifying and spasmolytic effects.

From a hygienic and toxicological point of view, the ability of organic acids to influence mineral metabolism is noted. So, oxalic acid intensively binds calcium, and citric acid, on the contrary, promotes its absorption by the human body. The aforementioned properties of organic acids must be taken into account when formulating food and beverages with an orientation of the latter to certain categories of consumers.

Based on the generalized data obtained using epidemiological methods, organic acids are included in the list of mandatory components of an optimal diet. An adequate level of consumption of the sum of organic acids (angelic, tartaric, glycolic, glyoxalic, citric, isolimonic, malic, fumaric, cinnamic and couple-kumarovaya) for a modern person, whose vital activity is characterized by low energy consumption (at the level of 2300 kcal per day), is 500 mg / day; the upper permissible level of consumption is 1500 mg / day. The adequate level of consumption of valeric acid is especially stipulated -
2 mg / day - and succinic acid - 200 mg / day (the upper permissible levels of consumption are 5 mg and 500 mg, respectively).

The main food applications are citric, tartaric and lactic acids, mainly in the production of confectionery, soft drinks, canned food and food concentrates. Free organic acids and their salts also find medical use: acetic acid is widely used in the manufacture of pharmaceutical products (many drugs are more soluble, and, accordingly, more assimilable in the form of acetates); succinic acid finds independent use as a pharmaceutical; salts of malic acid (for example, malic acid iron) are used in the treatment of anemia; the sodium salt of citric acid is used as a preservative in blood transfusions; citrate copper is sometimes used in the treatment of eye diseases; Wastes from the production of grape wines - sour potassium tartrate, "tartar" (cremotartar) - are used in medicine and the food industry to obtain crystalline tartaric acid.

References to section 3

1. Grebinsky, S. Biochemistry of plants / S. Grebinsky. - Lviv: Publishing house of Lviv University, 1967 .-- 272 p.

2. Shcherbakov, V.G. Biochemistry: textbook / V.G. Shcherbakov, V.G. Lobanov, T.N. Prudnikova, A.D. Minakov. - SPb .: GIORD, 2003 .-- 440 p.

3. Markh, A.T. Biochemistry of fruit and vegetable conservation / A.T. March. - M .: Food industry, 1973 .-- 372 p.

4. Tsapalova I.E. Examination of wild fruits, berries and herbaceous plants: study guide / I.E. Tsapalova, M.D. Gubina, V.M. Poznyakovsky. - Novosibirsk: Publishing house of Novosibirsk University, 2000 .-- 180 p.

5. Plotnikova, T.V. Expertise of fresh fruits and vegetables / T.V. Plotnikova, V.M. Poznyakovsky, T.V. Larina. - Novosibirsk: Sib. University. publishing house, 2001 .-- 302 p.

6. The chemical composition of food products / ed. THEM. Skurikhin and M.N. Volgareva. - M .: Agropromizdat, 1987 .-- 223 p.

7. Muravyova, D.A. Pharmacognosy / D.A. Muravyova. - M .: Medicine, 1981 .-- 656 p.

8. Rodopulo, A.K. Biochemistry of winemaking / A.K. Rodopoulo. - M .: Food industry, 1971. - 374 p.

9. Karklinsh, R.L. Biosynthesis of organic acids / R.L. Karklinsh, A.K. Traffic jams. - Riga: Zinatne, 1972 .-- 200 p.

10. Domaretsky, V.A. Production of concentrates, extracts and soft drinks: a reference book / V.A. Domaretsky. - Kiev: Harvest, 1990 .-- 245 p.

11. Chelnakova, N.G. Food products for body weight correction: new technologies, assessment of quality and efficiency: monograph / N.G. Chelnakova, E.O. Ermolaeva. - M .; Kemerovo: IO "Russian Universities"; Kuzbassvuzizdat - ASTI, 2006 .-- 214 p.

12. Poznyakovsky, V.M. Hygienic foundations of food, food quality and safety: textbook / V.M. Poz-nyakovsky. - Nsb .: Sib. univ. publishing house, 2004 .-- 556 p.

13. Production of food acids / under total. ed. E.I. Zhu-ravlevoy. - M .: Pishchepromizdat, 1953 .-- 236 p.

14. Smirnov, V.A. Food acids / V.A. Smirnov. - M .: Light and food industry, 1983. - 264 p.

Since I am a doctor by profession, on the role of acids in human life I know a lot. I'll tell you about those acids that are found in nature, as well as those that are most important from a medical point of view.

Where do acids occur naturally?

We encounter them every day, for example, raindrops seem clean only at first glance. In fact, they contain a lot of substances in dissolved form. For example, there is carbonic acid solution - carbon dioxide, or sulphuric acid, which is a consequence of the emission of exhaust gases. Our food is also rich in acids, for example lactic acid in kefir or carbonic acid in soda. Thanks to hydrochloric acid digestion is possible in our body, during which proteins are broken down for synthesis important elements - amino acids.

Organic acids

However, the most important for life on our planet are organic acidsthat play a particularly important role in the life cycle. Human cells are made up of protein and protein, so we need to eat to replenish these nutrients. However, for nutrition, only those proteins that contain amino acids... But what are amino acids? There are over 165 species, but only 20 are of value to the body, which act as main structural unit every cell.


Is our the body is able to synthesize only 12, naturally, subject to good nutrition. The remaining 8 cannot be synthesized, but only obtained from the outside:

  • valine - supports the exchange of nitrogen compounds. Dairy products and mushrooms;
  • lysine - the main purpose is the absorption, distribution of calcium in the body. Meat as well as bakery products;
  • phenylalanine - supports brain activity and blood circulation. Present in beef, soy and cottage cheese;
  • tryptophan - one of the key components of the vascular system. Oats, bananas and dates;
  • threonine - plays a role in the immune system, regulates liver function. Dairy products, chicken eggs;
  • methionine - strengthening the heart muscle. Present in beans, eggs;
  • leucine - promotes the restoration of bones and muscles. It is abundant in nuts and fish;
  • isoleucine - determines the level of sugar in the blood. Seeds, liver, chicken.

With a deficiency of one acid the body is unable to synthesize the required protein, which means that it is forced to select the necessary elements from other proteins. it leads to general imbalance, which develops into a disease, and in childhood causes mental and physical disabilities.

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