1 solution of acetic acid of 9

GOST R 54756-2011

Group H19

NATIONAL STANDARD OF THE RUSSIAN FEDERATION

MILK AND MILK PRODUCTS

Determination of the mass fraction of whey proteins by the Kjeldahl method

Milk and milk products. Determination of mass fraction of whey proteins with Kjeldahl method

OKS 67.100.10
OKSTU 9209

Introduction Date 2013-01-01

Foreword

The objectives and principles of standardization in the Russian Federation are established by Federal Law of December 27, 2002 N 184-ФЗ “On Technical Regulation”, and the rules for applying national standards of the Russian Federation are GOST R 1.0-2004 “Standardization in the Russian Federation. Basic Provisions”

Standard Information

1 DEVELOPED by the State Scientific Institution of the All-Russian Scientific Research Institute of the Dairy Industry of the Russian Agricultural Academy (GNU VNIMI of the Agricultural Agricultural Academy)

2 INTRODUCED by the Technical Committee for Standardization TC 470 "Milk and milk processing products"

3 APPROVED AND INTRODUCED BY Order of the Federal Agency for Technical Regulation and Metrology of December 13, 2011 N 945-st

4 ENTERED FOR THE FIRST TIME


Information on changes to this standard is published in the annually published information index “National Standards”, and the text of changes and amendments is published in the monthly published information index “National Standards”. In the case of revision (replacement) or cancellation of this standard, the corresponding notification will be published in the monthly published information index “National Standards”. Relevant information, notification and texts are also posted in the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet

1 area of ​​use

1 area of ​​use

This standard applies to milk and dairy products in part of raw milk, raw cream, drinking milk, drinking cream (hereinafter - the product) and establishes the determination of the mass fraction of whey proteins by the Kjeldahl method.

2 Normative references

This standard uses normative references to the following standards:

GOST R 12.1.019-2009 Occupational safety standards system. Electrical safety. General requirements and nomenclature of types of protection

GOST R ISO 5725-1-2002 Accuracy (trueness and precision) of measurement methods and results. Part 1. The main provisions and definitions

GOST R ISO 5725-6-2002 Accuracy (accuracy and precision) of measurement methods and results. Part 6. The use of precision values ​​in practice

GOST R 51652-2000 Rectified ethyl alcohol from food raw materials. Technical conditions

GOST R 52738-2007 Milk and milk processing products. Terms and Definitions

GOST R 53228-2008 Scales non-automatic action. Part 1. Metrological and technical requirements. Tests

GOST 12.1.004-91 Occupational safety standards system. Fire safety. General requirements

GOST 12.1.005-88 Occupational safety standards system. General sanitary and hygienic requirements for working area air

GOST 12.1.007-76 Occupational safety standards system. Harmful substances. Classification and general safety requirements

GOST 12.4.009-83 Occupational safety standards system. Fire equipment to protect objects. The main types. Accommodation and service

GOST 12.4.021-75 Occupational safety standards system. Ventilation systems. General requirements

GOST 61-75 Reagents. Acetic acid. Technical conditions

GOST 1770-74 (ISO 1042-83, ISO 4788-80) Laboratory volumetric glassware. Cylinders, beakers, flasks, test tubes. General technical conditions

GOST 3622-68 Milk and dairy products. Sampling and preparation for testing

GOST 4145-74 Reagents. Potassium sulfate. Technical conditions

GOST 4165-78 Reagents. Copper (II) 5-water sulfate. Technical conditions

GOST 4204-77 Reagents. Sulfuric acid. Technical conditions

GOST 4328-77 Reagents. Sodium hydroxide. Technical conditions

GOST 5833-75 Reagents. Sucrose. Technical conditions

GOST 6709-72 Distilled water. Technical conditions

GOST 9147-80 Porcelain laboratory ware and equipment. Technical conditions

GOST 9656-75 Reagents. Boric acid. Technical conditions

GOST 10929-76 Reagents. Hydrogen peroxide. Technical conditions

GOST 12026-76 Laboratory filter paper. Technical conditions

GOST 13928-84 Harvested milk and cream. Acceptance rules, sampling methods and preparation for analysis

GOST 14919-83 Electric stoves, stoves and household ovens. General technical conditions

GOST 19908-90 Crucibles, bowls, glasses, flasks, funnels, test tubes, and a tip made of transparent quartz glass. General technical conditions

GOST 25336-82 Laboratory glassware and equipment. Types, basic parameters and dimensions

GOST 25794.1-83 Reagents. Methods for the preparation of titrated solutions for acid-base titration

GOST 26809-86 Milk and dairy products. Acceptance rules, sampling methods and sample preparation for analysis

GOST 28498-90 Liquid glass thermometers. General technical requirements. Test methods

GOST 29227-91 (ISO 835-1-81) Glass laboratory glassware. Graduated pipettes. Part 1. General requirements

GOST 29251-91 (ISO 385-1-84) Glass laboratory glassware. Burettes Part 1. General requirements

Note - When using this standard, it is advisable to check the operation of reference standards in the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet or on the annually published information index "National Standards", which is published as of January 1 of this year , and according to the corresponding monthly published information signs, published in the current year. If the reference standard is replaced (modified), then when using this standard should be guided by a replacement (modified) standard. If the reference standard is canceled without replacement, the provision in which reference is made to it is applied in the part that does not affect this reference.

3 Terms and definitions

In this standard, the terms and definitions established by the regulatory legal act of the Russian Federation and GOST R 52738 are applied.

4 The essence of the method

The method is based on the preliminary precipitation of casein with a solution of acetic acid, the mineralization of the obtained filtrate with concentrated sulfuric acid in the presence of an oxidizing agent, an inert salt and a catalyst. This forms ammonium sulfate dissolved in sulfuric acid, which is converted into ammonia, distilling the latter into a solution of boric acid, quantitatively accounting for ammonium compounds by the titrimetric method and calculating the mass fraction of whey proteins in the analyzed sample of the product.

5 Measuring instruments, auxiliary equipment, dishes, reagents and materials

Scales according to GOST R 53228, ensuring weighing accuracy with limits of permissible absolute error of a single weighing ± 0.0001; ± 0.01 and ± 0.1 g

A laboratory liquid thermometer with a temperature measuring range from 0 ° С to 100 ° С, at the cost of dividing the scale of 1 ° С according to GOST 28498.

A 1000 W electric tile according to GOST 14919, which allows to maintain the temperature from 450 ° C to 500 ° C with an allowable error of ± 25 ° C.

Thermostatically controlled water bath, which allows to maintain the temperature from 0 ° С to 100 ° С with a tolerance of ± 2 ° С.

Flasks measured 1-100-2, 1-500-2, 1-1000-2 or 2-100-2, 2-500-2, 2-1000-2 according to GOST 1770.

Pipettes of execution of 1 or 2, 1 class of accuracy, type 2, with a capacity of 5 or 25 cm in accordance with GOST 29227.

Measuring cylinders 1-25-1, 1-50-1, 1-100-1, 1-1000-1 or 1-25-2, 1-50-2, 1-100-2, 1-1000-2, or 3-25-1, 3-50-1, 3-100-1, 3-1000-1, or 3-25-2, 3-50-2, 3-100-2, 3-1000-2 according to GOST 1770.

Burettes 1-1-2-25-0,1 or 1-2-2-25-0,1 according to GOST 29251.

Ball cooler or with a straight tube of versions 1, 2, 3, casing length 400 mm according to GOST 25336.

Tank-steam generator or flask of heat-resistant glass with a capacity of 2000 cm according to GOST 25336.

Kjeldahl flasks 2-250-TS according to GOST 25336.

Test tubes from quartz glass in accordance with GOST 19908.

Kapleulovitel of execution of KO-60 in accordance with GOST 25336.

Conical flasks 2, with a capacity of 250 cm according to GOST 25336.

Flat-bottomed flasks with ground stoppers with a capacity of 250 and 500 cm TC according to GOST 25336.

Laboratory glass beakers according to GOST 25336.

Funnels В-36-80, В-75-110 ХС according to GOST 25336.

Mortar porcelain with a pestle according to GOST 9147.

Glass porcelain with a capacity of 1000 cm according to GOST 9147.

Dropper glass laboratory according to GOST 25336.

Glass sticks melted.

Metal (porcelain) spatula or spoon.

Laboratory filter paper according to GOST 12026.

Bromocresol green, h.a.

Potassium sulfate according to GOST 4145, h.a.

Hydrogen peroxide according to GOST 10929.

Sulfuric acid concentrated according to GOST 4204 with a density of 1830-1840 kg / m, h.ch.

Hydrochloric acid, standard titer by, aqueous solution of molar concentration (HCl) = 0.1 mol / dm.

Boric acid in accordance with GOST 9656, ch.d.a.

Acetic acid according to GOST 61, an aqueous solution with an acetic acid volume fraction of 10%.

Rectified ethyl alcohol according to GOST R 51652.

Copper (II) 5-water sulfate according to GOST 4165, p.a.

Methylene blue, ch.d.a.

Methyl red, h.a.

Sodium hydroxide according to GOST 4328, ch.d.a.

Sucrose containing not more than 0.002% nitrogen according to GOST 5833.

Distilled water according to GOST 6709.

It is allowed to use other measuring instruments, auxiliary equipment, which are not inferior to the above in metrological and technical characteristics and provide the necessary measurement accuracy, as well as reagents and materials in terms of quality not worse than the ones mentioned above.

6 Sampling

Sampling and preparation of samples - in accordance with GOST 3622, GOST 13928 and GOST 26809.

If the determination cannot be carried out immediately after sampling, they are stored in a refrigerator at a temperature of (4 ± 2) ° C.

7 Preparation for measurement

7.1 Preparation of mixed catalyst

In a porcelain mortar, one part by weight of copper sulphate and 30 parts by weight of potassium sulphate are mixed, carefully ground with a pestle and mixed until a fine powder is obtained.

The shelf life of the mixed catalyst is not more than 1 month.

7.2 Preparation of 10% acetic acid solution

In a volumetric flask with a capacity of 100 cm is placed (10,000 ± 0,001) g of acetic acid and the volume of the solution was adjusted to the mark with distilled water.

The shelf life of the solution is not more than 1 month.

7.3 Preparation of a hydrochloric acid solution of molar concentration (HCL) = 0.1 mol / dm

Use the standard titer of hydrochloric acid. An aqueous solution is prepared in accordance with the attached instructions.

The shelf life of the solution in a dark dish is no more than 1 month.

7.4 Preparation of boric acid solution of mass concentration 40 g / dm;

(40,000 ± 0,005) g of boric acid are placed in a volumetric flask with a capacity of 1000 cm and dissolved in a small amount of distilled water at a temperature of (45 ± 5) ° C and thoroughly mixed. After cooling the solution to a temperature of (20 ± 5) ° C, the volume of the solution is brought to the mark with distilled water and stirred.

7.5 Preparation of mixed indicator

In a volumetric flask with a capacity of 100 cm is placed (0,200 ± 0,001) g of methyl red and (0,100 ± 0,001) g of methylene blue (or (0,100 ± 0,001) g of bromocresol green), dissolved in a small amount of ethanol. The volume of the solution is adjusted with ethyl alcohol to the mark and mix.

The shelf life of the mixed indicator in a tightly sealed dark container in a refrigerator at a temperature of (4 ± 2) ° C - not more than 10 days.

7.6 Preparation of an aqueous solution of sodium hydroxide mass concentration of 400 g / dm

(400,000 ± 0,005) g of sodium hydroxide are dissolved in a porcelain cup with a capacity of 1000 cm, dissolved in 700 cm of distilled water, stirred until complete dissolution of sodium hydroxide and cooled to a temperature of (20 ± 5) ° C and quantitatively transferred into a 1000 cm volumetric flask, the volume of the solution is adjusted to the mark with distilled water and stirred.

The shelf life of the solution - no more than 14 days.

7.7 Preparation of the device for the distillation of ammonia

The device for the distillation of ammonia is collected in accordance with Appendix A (Figure A.1).

In steam tank 1   through the funnel 2   distilled water is poured in (about 2/3 volume) and the tap is opened 3   and clamp 4 . Heat the water in the tank on the gas burner or hotplate 11 . Attach an empty Kjeldahl flask 10   to drip tray 7   and hydroxide funnel 5 and after the water in the tank begins to boil, close the tap 3 . Turn on the fridge 8 , put an empty conical flask under it 9   and "steamed the device" for 5-10 minutes.

Perhaps the use of automatic or semi-automatic device for distillation. Preparation of the device is carried out in accordance with the instructions for use.

8 Measurement conditions

When performing measurements in the laboratory, the following conditions must be met:

9 Taking measurements

9.1 In a conical flask with a capacity of 100 cm is placed 20.0 g of the analyzed product, heated in a water bath to a temperature of 40-45 ° C. In a heated sample, add 1 cm of 10% acetic acid solution and leave it alone for 10 minutes to precipitate casein. The resulting flakes are filtered twice through a folded paper filter to obtain a clear serum.

9.2. In a Kjeldahl flask or a quartz tube, place 2,000-3,000 g of filtrate obtained in 9.1. 1.50-2.00 g of the mixed catalyst is added and then 10 cm of concentrated sulfuric acid and 10 cm of a 30% hydrogen peroxide solution are carefully added. The flask is covered with a nozzle or a glass funnel, the quartz tube is covered with a special droplet separator and proceed to heating in an inclined position at an angle of 45 ° at a temperature of from 450 ° C to 500 ° C.

Care must be taken to ensure that the liquid in the flask continuously boiled and that there were no black unburned particles on the walls of the flask, washing them away with light circular motions.

If there are black particles on the neck of the flask, if they are not captured by condensate of acid vapor during boiling or acid while mixing the flask contents, cool the flask well, rinse these particles into the flask with a small amount of water, then continue burning.

After the liquid in the flask becomes discolored (a slightly greenish shade is allowed), heating is continued for another 30 minutes. Allow the flask to cool to a temperature of (20 ± 5) ° C, rinse the contents of the flask, washing the walls of the flask, from 20 to 30 cm of distilled water, and proceed to distill off the ammonia.

9.3 After preparation of the distillation apparatus according to 7.7, the taps are opened 3   and 6   and close the clamp 4 (see drawing of Appendix A). Under the refrigerator, instead of an empty flask, a flask with 25 cm of boric acid of a mass concentration of 40 g / dm and five drops of a mixed indicator is inserted so that the tip of the refrigerator is immersed in the solution. Instead of an empty Kjeldahl flask, a flask with a mineralized sample is attached.

Close the tap 6 60 ml of sodium hydroxide solution are poured into the funnel and gradually opening the tap 6   with gentle rocking of the Kjeldahl flask, pour in sodium hydroxide. Opening the clamp 4 close the taps 3   and 6 . In the refrigerator, vapors of the ammonia solution are condensed and transferred to a flask with a solution of boric acid. The distillation is continued for 10 minutes, counting from the moment when the boric acid in the receiving flask acquires a green color. After the end of the distillation, the end of the cooler tube is taken out of boric acid, rinsed with distilled water and the distillation process is continued for another 2 minutes. Then open the taps 3   and 6 close clamp 4 .

When using automatic devices for distillation, the process is carried out according to the attached instructions for use.

9.4 The contents of the receiving flask are titrated with an aqueous solution of hydrochloric acid of molar concentration (HCl) = 0.1 mol / dm until the indicator turns from green to violet.

9.5 The sample is analyzed twice in repeatability conditions in accordance with the requirements of GOST R ISO 5725-1 (Subsection 3.14).

9.6 To make an appropriate correction for the reagents in the measurement result, determine the mass fraction of nitrogen in the control sample, using instead of the analyzed product 2 cm of distilled water and (0.100 ± 0.001) g of sucrose. The determination of the mass fraction of nitrogen in the control sample is carried out according to three parallel determinations. For the final result of determining the correction for reagents take the arithmetic average of the results of three parallel determinations.

The control sample is carried out when replacing at least one of the reagents.

10 Processing of measurement results

10.1 Mass fraction of whey proteins,%, in the analyzed sample of the product is calculated by the formula

where is the volume of hydrochloric acid solution consumed for titration of the analyzed solution, cm;

  - the volume of hydrochloric acid solution consumed for titration in the control experiment, cm;

  - the actual molar concentration of hydrochloric acid, mol / dm, in accordance with the requirements of GOST 25794.1;

14.0067 - mass of nitrogen, equivalent to 1 dm of hydrochloric acid solution with molar concentration (HCl) = 0.1 mol / dm, g;

6.28 - the conversion factor of the mass fraction of nitrogenous substances in the analyzed sample to the mass fraction of whey protein;

0.95 is a correction factor that takes into account the mass fraction of non-protein nitrogen;

  - mass of the analyzed sample of 9.2, g;

1000 - cm conversion factor in dm.

Calculations are carried out up to the third decimal place.

The arithmetic average of the results of two parallel determinations, rounded to the second decimal place, is taken as the final result of determining the mass fraction of whey protein in the product.

10.2 Mass fraction of whey proteins in the total protein fraction of the analyzed product is determined by the formula

where is the mass fraction of whey proteins, determined by (1),%;

  - mass fraction of total protein in the analyzed sample,%. The determination of the mass fraction of total protein () is carried out by the Kjeldahl method. The conversion factor of nitrogenous substances in the analyzed sample to the mass fraction of total protein is 6.38.

Calculations of the mass fraction of whey proteins in the total protein fraction are carried out up to the third decimal place.

11 Control of accuracy of measurement results

  11.1 Metrological characteristics of the method

The assigned characteristics of the error and its components of the method for determining the mass fraction of whey proteins according to (1) at 0.95 are given in Table 1.


Table 1

11.2 Verification of the acceptability of measurement results obtained under repeatability conditions

The acceptance of the results of measurements of the mass fraction of whey proteins obtained under repeatability conditions (two parallel determinations, 2) is checked against the requirements of GOST R ISO 5725-6 (clause 5.2.2).

Measurement results are deemed acceptable provided:

where, - the values ​​of two parallel measurements of the mass fraction of whey proteins, obtained under repeatability conditions;

  - the limit of repeatability (convergence), the value of which is given in Table 1.

If this condition is not met, then repeated measurements and verification of the acceptability of the measurement results under repeatability conditions are carried out in accordance with the requirements of GOST R ISO 5725-6 (clause 5.2.2).

When you repeat the specified standard, find out the reasons leading to unsatisfactory analysis results.

11.3 Verification of the acceptability of measurement results obtained under reproducibility conditions

The acceptance of the results of measurements of the mass fraction of whey proteins obtained under reproducible conditions (in two laboratories, 2) is checked against the requirements of GOST R ISO 5725-6 (clause 5.3.2.1).

Measurement results performed under reproducibility conditions are considered acceptable provided that:

where, - the values ​​of two parallel measurements of the mass fraction of whey proteins, obtained in two laboratories in reproducible conditions;

  - reproducibility limit, the value of which is given in table 1.

If this condition is not met, then perform the procedures in accordance with the requirements of GOST R ISO 5725-6 (clause 5.3.3).

12 Registration of the determination results

The final measurement result,%, at 0.95 is expressed as:

where is the arithmetic mean value of the results of two parallel determinations,%;

  - boundaries of absolute measurement error,%.

13 Security Requirements

When performing work it is necessary to observe the following requirements:

- the laboratory room must be equipped with a common supply and exhaust ventilation in accordance with the requirements of GOST 12.4.021. The content of harmful substances in the air of the working area shall not exceed the norms established by the requirements of GOST 12.1.005;

- safety requirements when working with chemical reagents in accordance with the requirements of GOST 12.1.007;

- safety requirements when working with electrical installations in accordance with the requirements of GOST R 12.1.019.

The laboratory room must comply with fire safety requirements in accordance with the requirements of GOST 12.1.004 and be equipped with fire extinguishing agents in accordance with the requirements of GOST 12.4.009.

Appendix A (reference). The scheme of the device for the distillation of ammonia by the Kjeldahl method

Appendix A
(reference)

A.1 The scheme of the device for the distillation of ammonia by the Kjeldahl method is shown in Figure A.1.

1   - tank steam generator (or a flask from heat-resistant glass with a capacity of 2000 cm); 2   - funnel; 3   - crane; 4   - clamp; 5   - hydroxide funnel; 6   - crane; 7   - drip tray; 8   - fridge; 9   - conical flask with a capacity of 250 cm; 10   - Kjeldahl flask; 11   - electric tile

Figure A.1

Bibliography

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Preparation of solutions. Equivalent acetic acid is equal to its molecular weight, 3 = 60.05, since the acid is monobasic. To prepare 2 n. the solution must be in 1 l of a solution of 60.05-2 = 120.10 g of CH3COOH. The available glacial acetic acid contains 99.8% of CH3COOH (p = 1.0503), it will require 100: 99.8 = X: 120.10; 120.10Х ХЮ0: 99.8 = 120.34 g, which will be 120.34: 1.0503 = 114.6 ml.

80% acetic acid will need 140 ml to dissolve in water and dilute to 1 l.

To prepare 6 n. Acid solution requires 420 ml of 80% acetic acid or 344 ml of ice-cold (99.8%) per 1 liter of solution.

Cleaning and receiving. 1. Acetic acid boils at 118.2 ° C and is easily distilled in a conventional distillation apparatus. In the distillation flask is placed a little anhydrous sodium acetate and pour acetic acid not more than 2 / s capacity of the flask. For a uniform boiling of the acid, the glass pieces or capillaries are drained into the flask and heated in a sand bath. Receiving flask should be open. Avoid hot acid burns.

2. Acetic acid can be obtained in the laboratory from

sodium acetate. 100 g are placed in the distillation apparatus.

anhydrous sodium acetate, add 800 g (435 ml) of concentrated sulfuric acid and heat for distillation

UNHC. To the distillate add 1 g of dichromate (or

potassium permanganate) and 5 g of anhydrous sodium acetate,

shaken, the liquid is drained and again distilled. The output --60 g (80%).

To obtain anhydrous sodium acetate, the CH3CO0Xa-3H20 crystalline hydrate is placed in a porcelain dish and heated on a weak burner flame. The acetate is melted and after evaporation of a significant part of the water hardens again. As the flame increases, the hardened acetate melts again. Heat a few more minutes, preventing the decomposition and tarification of salt. Hardened, still hot salt is ground in a porcelain mortar and transferred to a jar with ground glass stopper.

3. To obtain glacial acetic acid spend

fractional freezing. The acid is cooled to 0 ° C; at

this forms crystals that stand for several hours at 4 ° C, then the liquid is drained. By

weak heating the crystals dissolve and then by

cooling to 0 ° C they crystallize again, and the remaining liquid is drained.

Precautionary measures

Glacial acetic acid causes severe skin burns. Acid fumes strongly irritate mucous membranes. Contact with chromic anhydride, sodium peroxide and nitric acid is dangerous, as ignition can occur. Stewed with water.

Acetic acid is stored in glass vessels at a temperature above 16 ° C. Below 16 ° C, it becomes solid and, expanding, can break the vessel. Acetic acid should be stored separately from oxidizing agents - chromic anhydride, sodium peroxide and nitric acid.

AMMONIA AND ALKALI

Ammonia (ammonia water, ammonium hydroxide) NH * OH (M 35.05)

Properties Aqueous ammonia is a colorless transparent liquid with a strong odor. Commercially available ammonia contains 25-27% NH3; p = 0.901-f-O, 907. Gaseous ammonia at low concentrations in the air causes irritation of the eyes and nasal mucosa, nausea and headaches. It is very dangerous to get into the eyes of aqueous solutions of ammonia.

Cold water vigorously absorbs ammonia. 1176 ml (0.907 g) dissolve in 1 ml of water at 0 ° С, and 702 ml of ammonia (NH3) at 20 ° С. When boiling a solution of ammonia completely volatilizes.

Gaseous ammonia is liquefied under pressure of 846 kPa (8.46 atm) at 20 "C, forming a readily mobile, colorless liquid boiling at –33.4 ° C; at -77" C it hardens. Liquid ammonia is stored in cylinders. Air density is 0.5962.

Gaseous ammonia in an oxygen atmosphere can burn with a greenish flame, forming nitrogen and water. A mixture of 4 volumes of ammonia with 3 volumes of oxygen explodes strongly when ignited. It can dissolve in ethanol and other alcohols.

Ammonia destroys cork and rubber plugs. It is better to store ammonia in plastic containers, as it is

easily contaminated with silica leached from glass walls. Do not keep bottles with ammonia solutions near heaters, as this may lead to their rupture.

Ammonia solutions are prepared on the basis of its density and the percentage of NH3 in it (Table 11).

TABLE 11

Raft-bone

Density

NH „g in 1 l

Density

NHA WATER SOLUTIONS DENSITY AT 20 "C

21,5 22,1 22,8 23,4 24,0 24,7 25,3 26,0 26,7 27,3 28,0 28,7 29,3 30,0 30,7 31,4 32,1 32,8 33,6 34,4

0,918 0,916 0,914 0,912 0,910 0,908 0,906 0,904 0,902 0,900 0,898 0,896 0,894 0,892 0,890 0,888 0,886 0,884 0,882 0,880

9,87 10,4 11,0 11,5 12,5 12,6 13,1 13,7 14,3 14,9 15,5 16,1 16,7 17,2 17,9 18,5 19,1 19,7 20,3 20,9

94,55 99,42 104,5 109,4 114,3 119,3 12

Vinegar - a product used in cooking as a seasoning and preservative, containing a large amount of acetic acid, obtained from food-grade alcohol-containing raw materials, by microbiological synthesis using acetic acid bacteria. It is a colorless liquid with a specific aroma and a strongly sour taste.

The first vinegar, by fermentation of wine, was obtained about 3 thousand years ago. Then winemakers found that if you do not clog the grape wine after cooking, then after a few weeks it sours and turns into a caustic and acidic product that can be used as a seasoning and preservative. A little later, vinegar learned to cook from honey, vegetables, grains and fruits. But the principle of vinegar preparation has not changed over time: alcohol fermentation is first used, and then acetic acid.

Vinegar Information:

The composition of vinegar:

Vinegar is about:

• 97% of the water;
• 3% of carbohydrates.

Vinegar is natural and synthetic. Natural vinegar, depending on the product, on the basis of which it is made, contains tartaric, malic, citric, succinic acid, acetic, oxalic, lactic, as well as aldehydes, alcohols and water. Synthetic vinegar contains acetic acid and water.

Vitamin and mineral composition of natural vinegar depends on the product on the basis of which it is made. Apple cider vinegar contains such vitamins as A, B1, B2, B6, C, E and minerals - calcium, magnesium, sodium, iron, potassium, copper, sulfur and phosphorus.

Wine vinegar contains such vitamins as A, B5, C and minerals - potassium, fluorine, sodium, zinc, copper, manganese, calcium, iron, magnesium and phosphorus. In the synthetic table 9% vinegar, vitamins and minerals are missing.

The caloric content of 100 grams of vinegar depends on its type:

• synthetic table 9% vinegar - 11.3 kcal;
• apple vinegar - 21 kcal;
• wine vinegar - 9 kcal;
• rice vinegar - 41 kcal;
• malt vinegar - 54 kcal.

Types of vinegar:

Vinegar is classified according to the principle of preparation, the percentage of acetic acid, and the original substance, on the basis of which it is prepared.

Vinegar on the principle of cooking is:

• natural, derived from natural products;
• synthetic, obtained by diluting acetic acid produced by chemical means.

• 3% vinegar;
• 5% vinegar;
• 6% vinegar;
• 9% vinegar;
• any other% acetic acid content.

Vinegar on a product on the basis of which it is made happens:

1. Alcoholic. This vinegar is produced by fermenting alcohol. It does not have a pleasant odor and is mainly used for marinating meat.
2. Apple. It is made from apple cider. Most popular in Russia, USA and France. It has a pleasant aroma and slightly sour taste. It is used mainly for cooking fish dishes, pickling vegetables and acidifying sauces.
3. Wine. This type of vinegar is obtained by fermenting wine or juice. It is widely distributed in wine-making countries such as France. It happens white and red, depending on which wine it is made from. It has a pleasant smell. Mainly used for cooking marinades, sauces, salad dressing.
4. Rice. It is produced on the basis of sticky rice varieties, it is black, red and white. Most common in Asian countries. It is used mainly for the preparation of sushi, rice noodles, seafood, gravies and sauces. He is a good marinade.
5. Malt. This type of vinegar is obtained on the basis of beer wort. Most popular in the UK. It has a delicate taste and aroma. It is mainly used for pickling fish and vegetables, as well as for canning. The British use it as a spice in their popular dish - fish and chips.
6. Coconut. It is made on the basis of coconut milk. Popular in the Philippines and in India. It has a sweet taste and a strong smell. Suitable for marinating pork and seafood and chicken salad dressings.
7. Reed. This type of vinegar is produced by fermenting cane sugar syrup. Popular in southern countries where cane grows. It has a rich taste and unusual aroma. Perfect as a seasoning for fried poultry, fish and pork dishes.

How to dilute vinegar:

It often happens that there is acetic essence or vinegar with a higher concentration of acetic acid than is required in the recipe. In this case, it is not necessary to go to the store for vinegar with the desired concentration of acetic acid, because it can be diluted with water. Make it simple - you need to calculate the proportions to mix vinegar and water, and then mix.

(Initial concentration of vinegar / Required concentration of vinegar) - 1.

For example, you have a tablespoon of 70% vinegar essence, and you want to get 9% vinegar from it. We use the formula: (70% / 9%) - 1 = 7.8 - 1 = 6.8. The resulting value is rounded for simplicity to 7. It follows from the formula that in order to obtain 9% of vinegar from 70% of vinegar, it is necessary to mix a tablespoon of 70% of vinegar with 7 spoons of water.

By this principle, it is possible to calculate the number of parts of water that must be added to concentrated vinegar to obtain vinegar with any lower content of acetic acid. It is only necessary to remember that the mixed parts should be equal - if you took a teaspoon of the original vinegar, then add parts of the water to it with teaspoons, if you took a tablespoon of the original vinegar, then you need to dilute it with tablespoons of water, if you took 100 milliliters of the original vinegar it is necessary to dilute it with so many parts of water 100 milliliters, which are obtained by the formula, that is, 100 milliliters multiplied by the result of the formula.

Below are tables with proportions for diluting vinegar:

Dilution of vinegar essence:

In the calculation field of this table indicates the number of parts of water that must be added to 1 part of the original vinegar. Parts must be equal. For example, to obtain 3% vinegar from 70%, it is necessary to add 22.4 equal parts of water to 1 part of 70% essence. For example, if a portion is a teaspoon, then 1 teaspoon of 70% of the essence is mixed with 22.4 teaspoons of water. For simplicity, the values ​​can be rounded up.

Dilution of vinegar:

In the calculation field of this table indicates the number of parts of water that must be added to 1 part of the original vinegar. Parts must be equal. For example, to get 3% vinegar from 7%, you need to add 1.4 equal parts of water to 1 part of 7% vinegar. For example, if a portion is a teaspoon, then 1 teaspoon of 7% vinegar is mixed with 1.4 teaspoons of water. For simplicity, the values ​​can be rounded up.

How to cook vinegar at home:

If you want to use natural vinegar in dishes, you can cook it yourself. Most often in Russia, apple or wine vinegar is prepared at home.

Recipes for homemade apple cider vinegar:

1. Apple vinegar from overripe apples:

To create apple cider vinegar for this recipe you will need the following ingredients:

• overripe apples - 1 kilogram;
• granulated sugar - 50 grams for sweet apples or 100 grams for sour apples;

In addition to the ingredients, you will need a large enameled pan and a jar.

1. Rinse the apples well.
2. Cut the apples and chop the pieces.
3. Boil water and cool to 70 degrees Celsius.
4. Transfer the crushed apples into an enamel pan and pour hot water over so that the water hides the apples a couple of centimeters of water.
5. If the apples are sweet, add 50 grams of sugar to the pan, and if they are sour, add 100 grams. Mix.
6. Put the pot in a dark and warm place and cover with a cloth. Leave for 2 weeks. Periodically stir with a wooden spoon.
7. Strain the contents of the pot into the jars, leaving the place to the brim for the fermentation of vinegar, as it will increase in volume during fermentation.
8. Leave for 2 weeks in a warm and dark place for further fermentation. If the liquid has brightened and acquired a pleasant sour taste, the fermentation process is over.
9. Strain the vinegar and pour into bottles for storage and use. Cover tightly with bottle caps and store in a dark place.

Vinegar from overripe apples is ready!

2. Apple cider vinegar from ordinary apples:

To create apple cider vinegar for this recipe will need the following ingredients:

• apples - 1.5 kilograms;
• real honey - 150 grams;
• rye bread - 50 grams;
• water - 2 liters;

In addition to the ingredients you will need a large enamel pan, jars and a grater.

If everything is, then you can proceed to creating apple cider vinegar, following the step-by-step recipe:

1. Boil 2 liters of water and cool to room temperature.
2. Rinse the apples well.
3. Grate apples on a coarse grater. Do not throw out the hearts.
4. Put grated apples with hearts in an enamel pan and pour 2 liters of boiled water at room temperature, while not topping up the edges, leave a place for fermentation.
5. Put in a jar 50 grams of rye bread and 150 grams of real bee honey.
6. Put the pot in a warm and dark place, cover with a cloth and leave for 12 days. Periodically stir with a wooden spoon.
7. Then strain the contents of the pan into jars and cover them with a cloth.
8. Leave in a dark and warm place for a month. If the liquid has brightened and acquired a pleasant sour taste, the fermentation process is over.
9. Strain the vinegar and pour into bottles for storage and use. Cover well and store in a dark place.

Vinegar from ordinary apples ready!

Recipe for Homemade Wine Vinegar:

To prepare vinegar at home you will need:

• grapes - the floor of a three-liter can;
• granulated sugar - 140 grams;
• water.

In addition to the ingredients you need a three-liter jar.

If all the ingredients are there, then you can proceed to creating wine vinegar by following the step-by-step recipe:

1. Boil a little more than half a three-liter can of water. And then cool to room temperature.
2. Wash grapes well, pick diseased berries and discard.
3. Lay grapes up to half a three-liter jars.
4. Well knead grapes in a can hand.
5. Add half of the boiled water at room temperature to the jar.
6. Add 70 grams of sugar.
7. Mix well with a wooden spoon.
8. Cover the jar with gauze and place in a dark and warm place for 12 days. Stir once a day with a wooden spoon.
9. Strain the grape juice, squeeze the pulp and throw it away.
10. Strain the juice in a three-liter jar.
11. Add 70 grams of sugar and mix well with a wooden spoon.
12. Cover the jar with gauze and put in a dark and warm place for 2 months.
13. As soon as the mixture ceases to ferment and brightens a little, strain it into glass bottles.
14. Bottles corked and stored in a cool dark place.

Wine vinegar is ready!

What to replace the vinegar:

There are situations when you need to prepare a dish that includes vinegar in the recipe, but there is no vinegar at home. Then the question arises, what can replace the vinegar in the recipe. Everything is very simple. Vinegar can be replaced with citric acid or lemon juice.

Citric acid vinegar replacement ratio:

To obtain the equivalent of 70% acetic essence, you need to dilute 1 tablespoon of citric acid in 2 tablespoons of water.

Production technology of vinegar:

In general, the technological scheme of cooking vinegar in the production includes 7 stages:

1. First, the process of preparing the wort is carried out by mixing water, alcohol, various salts and sugars, which promotes the development of bacteria that will oxidize the main product and release acetic acid.
2. Next, in the generator-oxidants enter the filler in the form of birch or beech shavings, which irrigate with the wort and the product for oxidation, for example, alcohol. Fermentation occurs. Alcohol is oxidized to acetic acid for 5 days.
3. Next, the resulting vinegar is drained and clarified using gelatin and activated charcoal.
4. The liquid is filtered from the precipitate.
5. The vinegar is then diluted with water to form a solution with the required content of acetic acid.
6. Next, the vinegar is pasteurized to increase its shelf life.
7. Poured into the container and packaged.

Vinegar is produced according to “GOST R 56968-2016 Table vinegar. Technical conditions.

The shelf life of vinegar depends on its type and the percentage of acetic acid, it is listed on the label.

The benefits of vinegar:

Only natural vinegar containing vitamins and minerals can be beneficial to health, and synthetic vinegar does not bear any benefit to the human body, since it does not contain minerals and vitamins.

It should be immediately noted that natural vinegar can benefit human health only if it is added to dishes as seasoning or preservative moderately, in the proportions indicated in proven recipes. Just so you can not drink vinegar, so you can get a chemical burn of the gastrointestinal tract and cause serious harm to the body. That is why vinegar should be kept out of the reach of children.

The benefits of apple cider vinegar:

Apple cider vinegar is made from apple juice, due to which it is saturated with minerals and vitamins that are contained in apples. A small amount of apple cider vinegar, which enters the body as part of the main course, helps strengthen the immune system, due to the presence of large amounts of vitamins and minerals. Apple cider vinegar stimulates metabolic processes and speeds up digestion. Useful in that it improves the removal of toxins and toxins from the body. It reduces cholesterol and improves the condition of the blood vessels. It has antiseptic and diuretic properties. Helps strengthen hair and nails.

The benefits of wine vinegar:

Wine vinegar is made from grape juice, due to which it is saturated with minerals and vitamins that are contained in grapes. Getting into the body as part of the main dish, wine vinegar, slows down the aging process, reduces cholesterol levels, cleanses the blood vessels and strengthens the cardiovascular system. Improves the functioning of the lungs, gastrointestinal tract and urinary system. Wine vinegar normalizes the nervous system, improves hair and nails. It is an antioxidant and antiseptic.

Harm of vinegar:

Vinegar can cause the greatest harm to the body if it is drunk as a liquid. After that, a person receives a chemical burn of mucous membranes, food poisoning and renal failure occurs. That is why vinegar should be consumed only in small quantities in the composition of the main dishes prepared according to proven recipes. A bottle of vinegar should be kept out of the reach of children in order to avoid poisoning the child.

But as part of the dishes, vinegar can be harmful and contraindicated for people with diseases of the stomach and intestinal tract, such as gastritis, ulcers, colitis, enteritis, and increased acidity. Vinegar can harm these categories of people because it can aggravate these diseases. Also, do not use vinegar for people with obesity, nervous disorders, hypertension, nephritis, hepatitis, cholecystitis and cystitis.

Healthy people, without the mentioned diseases, vinegar should be consumed moderately as part of dishes prepared according to proven recipes. Only in this case, vinegar will not harm the body, and natural vinegar will have a beneficial effect on the body.