6.4.2.1 Measuring instruments, auxiliary equipment, utensils and materials

Areometers in accordance with GOST 18481, type AM, with a scale division of 0.5 kg / m 3, without a thermometer or type AMT, with a graduation of 1.0 kg / m3, with a thermometer.

Cylinder - 1 39 (45, 50) / 265 (280, 415) in accordance with GOST 18481.

Liquid glass thermometer in accordance with GOST 28498, measuring range from 0 ºС to 100 ºС and a scale division of 0.5 ºС.

Laboratory filter paper in accordance with GOST 12026.

It is allowed to use other measuring instruments, auxiliary equipment that are not inferior to the above in terms of metrological and technical characteristics and provide the necessary measurement accuracy.

6.4.2.2 Preparing to take measurements

The density of the product is determined at a temperature of (20.0 ± 2.0) o C. If the temperature of the test product does not correspond to the specified one, the sample is heated in a water bath or cooled under a stream of cold water.

Hydrometers and glass cylinders should be thoroughly washed with detergent solutions, rinsed with distilled water, and the remaining moisture removed with filter paper.

After preparing the hydrometer for measurement, do not touch its working surface with your hands. The hydrometer is taken by the upper part of the rod, free from the scale.

A sample with a volume of 0.10 or 0.25 dm 3 is thoroughly mixed and carefully, in order to avoid the formation of foam, poured along the wall into a dry cylinder, which should be kept in a slightly tilted position.

6.4.2.3 Making measurements

The cylinder with the test product sample is placed on a flat horizontal surface and the temperature of the sample is measured. The temperature readings are counted not earlier than 2–4 minutes after the thermometer is lowered into the sample.

A dry, clean hydrometer is lowered slowly into the test sample, immersing it until 3-4 mm remains to the expected mark of the areometric scale, then leaving it in a free floating state. In this case, the hydrometer should not touch the cylinder walls.

The location of the cylinder with the sample on a horizontal surface should be, in relation to the light source, convenient for reading the readings on the density scale and on the thermometer scale.

First density reading ( ρ 1) is carried out visually from the hydrometer scale 3 minutes after it has been established in a stationary position. Thereafter, the hydrometer is carefully raised to the level of the ballast in it and again lowered, leaving it in a free floating state. After establishing it in a stationary state, a second reading of the density readings is carried out ( ρ 2). When reading density readings, the eye should be at the level of the meniscus. The reading is carried out along the upper edge of the meniscus.

The readings on the AM and AMT hydrometers are counted up to half of the smallest division of the scale.

The discrepancy between parallel density measurements should not exceed 0.5 kg / m 3.

6.4.2.4 Processing of measurement results

The mean value of the hydrometer readings at the temperature of the test sample (20.0 ± 2.0) o C is the arithmetic mean of the results of the two readings ρ 1 and ρ 2 obtained under repeatability conditions.

Reproducibility limit R Is the absolute difference between the results of two parallel measurements obtained under reproducibility conditions - at a confidence level at R= 0.95 should not exceed 0.8 kg / m 3.

The limits of the permissible absolute error in determining the density of milk whey by the areometric method are ± 0.5 kg / m 3.

Conversion of the density value of whey to the mass fraction of dry substances is carried out in accordance with table 2.

Table 2

Density, kg / m 3	Mass fraction of dry substances,%
cheese whey	cottage cheese and casein whey
	5,60	5,40
	5,80	5,60
	6,00	5,70
	6,20	5,90
	6,30	6,10
	6,40	6,20
	6,50	6,30
	6,70	6,50
	6,90	6,80
	7,20	7,00
	7,40	7,25

Method for determination of mass fraction of dry substances by drying

The essence of the method

The method is based on the change in the mass of the sample of the analyzed product under the influence of temperature.

6.4.3.2 Measuring instruments, auxiliary equipment, glassware, materials and reagents

Scales of non-automatic operation in accordance with GOST OIML R 76-1 with limits of permissible absolute error no more than ± 0.1 mg.

Electric drying cabinet without forced convection (ventilation) of air, providing temperature maintenance (102 ± 2) о С.

Mechanical watches in accordance with GOST 3145.

Electric tiles in accordance with GOST 14919.

Pipettes 1 (2) –1 (2) –10 in accordance with GOST 29228.

Aluminum laboratory buckets with a diameter of 50 mm, a height of 38 mm
GOST 25336.

Desiccator 2-100 (140, 190) in accordance with GOST 25336.

Glass sticks.

Sieve with openings 1.0–1.5 mm.

Crucible tongs.

Filter paper in accordance with GOST 12026.

Washed and calcined sand.

Hydrochloric acid in accordance with GOST 3118, concentrated.

Calcium chloride technical according to GOST 450, anhydrous, calcined.

Distilled water in accordance with GOST 6709.

All reagents used must be of the chemical grade or analytical grade.

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

6.4.3.3 Preparation for measurement

The sand is sieved onto a baking sheet through a sieve with a hole diameter of 1.5 mm, then through a sieve with a hole diameter of 0.5 mm. The part of the sand that remains on the second sieve is taken into the cup, and washed several times with drinking water until a transparent layer above the sand. The water is drained, a solution of hydrochloric acid is poured in until the sand is completely covered and left for 12-14 hours, stirred with a spatula (spoon) 3-5 times.

Hydrochloric acid is drained and the sand is washed with drinking water by decantation until neutral (control is carried out using indicator paper). Then the sand is washed with distilled water, transferred to an evaporation cup, dried in an oven at a temperature of (130 ± 5) o C and calcined in a muffle furnace at a temperature not lower than 500 o C until the organic matter is completely removed (10 minutes after the cessation of smoke ).

The prepared sand is stored in a plastic container with a closed lid.

6.4.3.4 Making measurements

A metal bottle with 20–30 g of sand, prepared according to 6.4.3.3, and a glass rod that does not protrude beyond the edges of the bottle, is placed in a drying oven at a temperature of (102 ± 2) о С and kept at this temperature for 30–40 minutes. Then the bottle is removed from the cabinet, placed in a desiccator, covered with a lid, kept for 40 minutes, then weighed. Measure 10 cm 3 of a specific product into a weighing bottle with a pipette and weigh. Then the bottle is placed in a drying cabinet. The beginning of drying is considered the time to reach the temperature (102 ± 2) о С in the air space of the drying oven.

After 2 hours, the bottle is removed from the drying oven, placed in a desiccator, covered with a lid, cooled for 40 minutes and weighed.

Subsequent weighings are carried out after drying after 1 hour until the difference between subsequent weighings is equal to or less than 0.001 g.

6.4.3.5 Processing of measurement results

Mass fraction of dry matter WITH,%, calculated by the formula (1)

where m- weight of a weighing container with sand and a glass rod, g;

m 0 - weight of the weighing bottle with sand, glass rod and product before drying, g;

m 1 is the mass of a weighing bottle with sand, a glass rod and a product after drying, g.

Calculations are carried out to the third decimal place, followed by rounding to the second decimal place.

The final measurement result is taken as the arithmetic mean of two parallel determinations performed under repeatability conditions and rounded to the second decimal place if the acceptability condition is met: the absolute difference between the results of two parallel measurements does not exceed the repeatability (convergence) limit, r= 0.10% at R=0,95.

Reproducibility limit R Is the absolute difference between the results of two parallel measurements, obtained under reproducibility conditions, - at R=0,95, should not exceed 0.20%.

The limits of the absolute measurement error at R= 0.95 are ± 0.10%.

When making bread products from wheat flour natural whey can be used:

to activate fermentative microflora, yeast suspension, liquid dough, etc.;

to intensify the dough preparation process, increase the nutritional value of bread products with sponge and accelerated methods of dough making and save flour;

for the production of varieties of bread, the recipe of which provides for its use.

When using milk whey to activate the fermenting microflora or to intensify the process of dough making, it is used instead of part of the water used to prepare the dough.
The amount of natural whey used depends on the type and baking qualities of the flour used, the type of bread products, the technological schemes used, as well as the acidity of the whey.

Approximate data on the consumption of natural in the production of bread products from wheat flour are given in Table 3.

Table 3

Name products	The ways cooking test	Whey consumption,% by weight of flour, in natural form	Whey consumption,% by weight of flour, on dry matter
Wheat flour bread and a mixture of wheat wallpaper with wheat flour, grade II	Any method used in baking	15 - 20	0,75 - 1,0
Wheat Bread II and I varieties	Spooky, unpaired	10 - 15	0,5 - 0,75
Bakery and pastries from flour of II, I and extra grades	Spooky, unpaired	7 - 10	0,35 - 0,5
Wheat baked goods flour of II, I and extra grades	Accelerated	10 - 15	0,5 - 0,75
Wheat pastries flour I and extra grade	Accelerated	10 - 15	0,5 - 0,6
Lamb products	Any way	5 - 10	0,25 - 0,5

If during production wheat bread are used, they are brought in natural both at the stage of making tea leaves for them, and in the process of preparing a nutritious mixture. When preparing a brew, it can replace either part of the water (about 20%) when brewing with hot water, or all of the water when brewing with live steam.

As a result, natural can be added in an amount of 6-10% to the mass of flour in the dough.

Good results are obtained by using natural pressed yeast to activate. In this case, it is used to dilute the tea leaves or to prepare nutrient mixture consisting of flour and natural in a ratio of 1: 3. Whey consumption in this case will be 4 - 6% by weight of flour in the dough.

As a result of the use of serum, lifting force improves, acidity increases faster, and foaming decreases.

The rest of the whey can be added while kneading the dough. Its total amount must comply with the recommendations given in the table, taking into account the type and quality of flour, the quality of whey and the dough preparation technology used at the enterprises.

With sponge methods of dough making, natural water can be added instead of part of the water both to the dough and to the dough.
At the same time, the fermentation time of the dough with milk whey is reduced by 40 - 60 minutes. The fermentation time of dough mixed with dough with milk whey is practically the same as usual. The introduction of whey directly during the kneading of the dough leads to a reduction in the duration of its fermentation by 20 - 40 minutes.

With accelerated methods of dough making (with the use of intensive kneading on a batch machine RZ-KhTI-3, on a liquid emulsified phase, etc.), it is advisable to use acidic types of whey obtained in the production of cottage cheese and edible casein.

When preparing dough by accelerated methods, the amount of whey required to obtain a dough with a given acidity is determined from the following ratio:

where: q t, q m, q syv - respectively the mass of dough, flour, whey;

K m, K syv - respectively, the acidity of flour (hail), whey (° T),

К т - the given initial acidity of the dough, degrees,

0.1 - coefficient of conversion of acidity (° T) in deg.

From this ratio, the amount of whey that must be added is determined to obtain a dough with a given acidity:

Example. Production sliced ​​loaves from wheat flour I grade weighing 0.4 kg.

Recipe for 100 kg of flour, kg

We accept the yield of dough from 100 kg of flour equal to 165 kg, acidity of Turner's 75 ° whey (7.5 degrees of acidity accepted in baking), acidity of flour 2.5 degrees, the given initial acidity of the dough is 2.2 degrees (followed by fermentation to acidity 2.6-2.8 degrees).

We determine the amount of whey that is needed to obtain 165 kg of dough (from 100 kg of flour) with an acidity of 2.2 degrees:

When making donut products, it is advisable to use whey for kneading dough. Whey dosage is 5-10% by weight of flour. The use of whey leads to a reduction in the duration of proofing of the dough by 5-10 minutes, an improvement in the physical properties of the dough and its cutting on dividing and seaming machines. The amount of waste when cutting such a dough is reduced.

The technological mode of cooking bagels and dryers with the use of whey in the dough instead of water practically does not change.
Lamb products are fragile, with good color, gloss and swelling properties.

Powdered milk whey (cheese)
Whey (cheese) is a dry powder obtained from milk processed during the production of cheese. It is obtained in four main stages: purification, pasteurization, thickening and drying. All components, except moisture, remain in the same ratio. Whey contains healthy proteins and lactose from milk. Its use in various industries is due to its high biological value, health benefits and relatively low cost. Basically, whey powder serves as a substitute for milk powder.

Baltic Food Company offers dry milk whey for your production.
Whey protein is the most easily digestible and in its composition it is closest to the protein of human milk. The immunostimulating effect of whey is associated with the composition of the (irreplaceable) amino acids of whey protein, it contains, in comparison with casein, 4 times more cysteine ​​and 19 times more tryptophan, which ensures the regeneration of liver proteins, the formation of hemoglobin and blood plasma proteins. Whey protein has been shown to increase levels of glutathione, one of the body's most important antioxidants. Whey protein contains minimal amount lactose, which is food for lactic acid bacteria (Lacto and bifidobacteria) and during the preparation of the drink it is utilized to monosaccharides. The main component of whey solids is milk sugar (lactose). Hydrolysis (decomposition) of lactose in the intestine proceeds slowly, in connection with which the fermentation processes are limited and the vital activity of the beneficial intestinal microflora is normalized. As a result, putrefactive processes, gas formation and absorption of toxic putrefactive products slow down. Milk whey contains a small amount of fat, 0.05-0.4%, but its quality is high. The value of whey milk fat is determined by the presence of phospholipids, which serve as oxygen transmitters and have a beneficial effect on blood coagulation, oxidation of fatty acids, and enhancement of enzyme activity. Whey fat is highly digestible due to the presence of small fat globules.

Using whey in baking

Whey powder is widely used in the bakery industry.
Before use in production, the whey is diluted with water at a temperature of 35-45 ° C in a ratio of 1: (10 -12).
When making bread with thick sourdough, it is recommended to add whey when kneading the dough. The amount of added dry whey is up to 1-2% of the total mass of flour used to make bread and bakery products. Whey enriches bread and bakery products essential amino acids, especially tryptophan and lysine, as well as calcium and phosphorus. At the same time, the yield of bread increases slightly, its quality improves, and the nutritional value increases.
Dry milk whey can be used in the production of donut products (simple donuts, butter, simple drying, etc.) to improve their quality. Powdered milk whey is added when kneading the dough in an amount of 0.5-1.0% by weight of flour. Lamb products are of the best quality - fragile, with good color, gloss and swelling properties. Physical properties are improved. It can be cut well on dividing and seaming machines. The amount of waste when cutting such a dough is reduced.

The consumption of dry milk whey in the production of bread products from wheat flour is shown in Table 1

Products	Dough preparation method	Consumption of dry milk whey in natural form,% by weight of flour
Bread from wheat wallpaper and a mixture of wheat wallpaper with wheat flour of 2 grade	Any method used in baking
Grade 1 and 2 wheat flour bread	Spooky, unpaired
Bakery and pastry products from flour of the highest, 1 and 2 grades	Spooky, unpaired
Bakery products from wheat flour of the highest, 1 and 2 grades	Accelerated
Pastries from wheat flour of the highest and 1 grades	Accelerated
Lamb products	Any way

The consumption of dry milk whey in the production of rye and rye-wheat breads is given in table 2

Use of whey in production confectionery, desserts
Powdered milk whey is used in the production of wafer sheets, cookies, gingerbread, as well as in the production of jelly, jelly, puddings, pastes, mousses.
In the production of confectionery products, whey powder is used to replace sugar and other types of raw materials in existing formulations and in the development of new types of products.

Candy

In the production of praline sweets based on confectionery fat, part of the icing sugar dry milk whey, which is introduced at the stage of preparation of the mixture in the amount of 10% by weight of powdered sugar on dry matter.
When producing sweet tiles, dry milk whey is introduced into the mixture together with the dry components provided for by the recipe (cocoa powder, sugar, etc.), in an amount of 10% of the sugar mass. At the same time, its consumption is reduced by 10% in terms of dry matter.
When producing peanut and sunflower halva dry milk whey is introduced before kneading halva in an amount of 9.4% in peanut and 10.4% in sunflower mass (in dry matter). This reduces the consumption of caramel mass by 43 kg, sunflower or peanut mass - by 15.1 kg / t.

Wafer sheets, cookies and gingerbread

Powdered milk whey is used when kneading dough for wafer sheets, sugar cookies and gingerbread, dissolving it in water with a temperature of 35-45 ° C in a ratio of 1:10. Accordingly, in the formulations of manufactured products, the amount of sugar is reduced by 1-2%.
When making sugar biscuits, some of the granulated sugar can be replaced with whey powder. In this case, the amount of sugar dry matter according to the recipe is reduced by the corresponding amount of dry matter introduced with whey. The consumption of whey powder per 1 ton of sugar biscuits is 15 kg, while saving 14.3 kg of sugar. Powdered milk whey is used in the production of sugar biscuits with a sugar content in the recipe of at least 100 kg.
In the production of custard gingerbread, dry whey is used in the preparation of the dough.

Candy fillings
In the production of fatty glazes, whey powder is introduced into a mixture with dry components provided for in the recipe (cocoa powder, sugar, etc.), in an amount of 5% by weight of sugar in the recipe, while the amount of sugar is reduced by 5% calculated on dry matter.
By producing chocolate nut fillings containing powdered milk, dry milk whey is used instead of dry milk in an amount of not more than 90 kg per 1 ton of filling. The whey is introduced together with the rest of the components at the stage of preparing the mixture for the fillings.
When preparing fatty milk fillings for waffles and wafer cakes, whey powder completely replaces milk powder. The technology for the production of fillings, waffles and wafer cakes does not change at the same time

desserts

Kissel
Produced from dry milk whey, diluted in water with a temperature of 35-45 ° C in a ratio of 1:10, with the addition of starch and flavorings.
One of the jelly recipes (kg per 1000 kg of product): dry milk whey - 89.04 diluted in water with a temperature of 30-35 ° C in a ratio of 1:10; granulated sugar-103 kg; starch-36.05 kg.

Jellies, puddings, mousses

Produced from dry milk whey, diluted in water with a temperature of 35-45 ° C in a ratio of 1:10, with the addition of gelling agents and flavorings.

The recipe for jelly, puddings, mousses, kg per 1 ton of product is shown in the table

Reconstituted serum
Low-fat cottage cheese
Fruit or berry syrup
Semolina
Gelling starch

Due to its unique properties, it has a beneficial effect on human health and progress technological processes, whey powder is widely used not only in the bakery and confectionery industry. Meat processing and dairy industry, production of food concentrates and baby food- this is not a complete list of development directions Food Industry, in which such a wonderful product as whey powder can be used.

Our experts will be happy to answer all your questions.

Dry milk whey -it is a powder obtained from a milk by-product by drying. You can dry the cheese mass or cottage cheese. Dry whey made from raw materials that have not been genetically modified.

Application of dry whey

dry whey

This product has a sweet-salty taste and a light yellow, sometimes white color. As such, it does not have a smell, only a slight specific aroma. The presence of lumps is allowed, but with mechanical stress they quickly disintegrate.

There are many uses for this product.

• Confectionery and bakery industry (raises the dough with the effect of yeast, improves taste qualities, perfectly distributes fat throughout the mass).
• Ice cream, whole milk products, dairy products, processed cheese, cottage cheese, fat and oil industry and condensed milk (increases viscosity, improves texture, increases nutritional value, creates a creamy texture, helps to reduce the freezing point of ice cream).
• Meat industry (increases the viscosity of the consistency, creates a beautiful color for the finished meat dish).
• Brewing industry (works as an enzyme activator in the production of beer wort).
• Sports nutrition (is a source of whey proteins and is used in the preparation of sports nutrition).
• Pet food.
• Cosmetic industry.

Whey powder can be prepared good jelly that will delight your little ones. To do this, strain a couple of glasses of liquid whey, heat to 70 ° C, add gelatin, berries, sugar, syrup or jam. Mix the whole mixture, pour into molds and put in the refrigerator.

The product is suitable for use within six months (maximum one year) from the date of manufacture, if the storage conditions are 18 (+/- 2) ° C with a humidity of more than 80%.

Composition and useful properties

dry whey promotes muscle building

Powdered whey has a fairly rich composition. It includes the following minerals and vitamins: vitamin A, organic acids, vitamin B2, vitamin PP, vitamin H, phosphorus, iron, iodine, potassium, cobalt, etc.

The dry whey contains almost all salts, microelements, soluble in water. It is especially rich in B vitamins, which are good sedatives. It should also be noted the important role of this product in vitamin deficiency. Taking into account the fact that there are many vitamins in dry whey, it replenishes the entire vitamin composition in the body.

The composition of the protein contained in milk whey is similar in composition to the protein of mother's milk, in contrast to cow's milk, which gives manufacturers the right to make children's food products from it. An important difference between fat in whey and fat in cow's milk is the degree of its dispersion, which contributes to easy absorption.

Almost everyone needs whey powder. For men, it has an anabolic effect on tissue and helps to build muscle mass. This can be considered the unraveled secret of nutrition for athletes. It helps women to remove toxins and excess fluid. It can be consumed daily, adding extra protein without gaining extra pounds. In addition, it can perfectly satisfy hunger, it is an effective means for a diet.

Serum is recommended for elderly people against latent forms of vitamin deficiency, atherosclerosis, hypertension and cardiovascular diseases. She helps children with vitamins, trace elements, salts, which help to increase immunity. The product improves blood pressure, increases vitality, and normalizes the intestinal microflora.

Serum obtained from goat milk... It helps with gastric and pulmonary insufficiency, with anemia.

Video: whey

In skim milk, buttermilk and milk whey, 50 ... 70% of milk solids are transferred. The conversion of dry matter from whole milk to whey is 52%. At the same time, milk sugar is almost completely transferred (96.0%). The conversion of proteins to whey is 24.3%. If in skim milk and buttermilk contains all milk proteins (the degree of their transition is 97.5 and 98.0%, respectively), then 22.5% of casein and 95% of whey proteins pass into milk whey. Chemical composition whey is given in table 1.

Table 1. The content of the main components in milk whey

The main component in the composition of milk whey is lactose, the composition is more than 70%. In milk whey, on average, 100 ml contains 0.135 mg of nitrogen, about 65% of which is part of protein nitrogenous compounds and about 35% is part of non-protein ones. The composition of protein nitrogenous compounds in whey ranges from 0.5 to 0.8% and depends on the method of coagulation of milk proteins adopted when obtaining the main product (cottage cheese, cheese, casein, etc.). The composition of the protein nitrogenous compounds of milk whey is shown in Table 2.

Whey proteins can serve as an additional source of arginine, histidine, methionine, lysine, threonine, tryptophan and leucine. This allows us to classify them as complete proteins that play an important role in the life of the body.

Whey contains all the essential amino acids. The composition of free amino acids in the cheese whey is 4 times, and in the cheese whey it is 10 times more than in the original milk.

Table 2 . Composition of whey proteins by fractions

The composition of carbohydrates in milk whey is similar to the carbohydrate component of milk - monosaccharides, oligosaccharides and amino saccharides. The main carbohydrate of whey is the disaccharide lactose, the composition of which is up to 90% of the total carbohydrate content. From monoses, glucose and galactose were found in serum - products of lactose hydrolysis in the process of processing milk into cheese and cottage cheese. Neuraminic acid and its derivatives, as well as ketopentose, were found in serum from amino saccharides. The serum contains serologically active oligosaccharides, as well as small amounts of arabinose.

Milk whey contains 0.05-0.5% fat, which is due to its content in the feedstock, and the technology for obtaining the main product. Separated whey has a fat content of 0.05-0.1%. The milk fat in the whey is crushed more than in whole milk, which has a positive effect on its digestibility. Almost all salts and microelements that make up milk, as well as those that are introduced during technological processing, pass into milk whey. The absolute content of the main ash elements in whey (in%) is shown in Table 3.

Table 3 - The content of the main ash elements in the whey composition

Mineral substances in whey are in the form of true and molecular solutions, in a colloidal and insoluble state, in the form of organic and non-organic salts. organic acids... The composition of inorganic salts includes 67% phosphorus, 78% calcium, 80% magnesium. The quantitative content of anions (5.831 g / l) and cations (3.323 g / l) in whey is similar to the content of trace elements in whole milk. Of the cations in serum, potassium, sodium, calcium, magnesium and iron prevail from anions - the remains of citric phosphoric, lactic and hydrochloric acids. In general, whey is a product with a natural set of vital minerals.

In addition to mineral compounds, water- and fat-soluble vitamins of milk are almost completely transferred to whey, and there are much more of them in the cheese whey than in the cheese whey. The relative content of vitamins in whey (in%) compared to their content in whole milk are shown in Table 3.

Table 3 - Relative content of vitamins in serum

The amount of pyridoxine, choline and, less often, riboflavin in serum often exceeds their content in whole milk, which is due to the vital activity of lactic acid bacteria. The content of vitamins in whey is subject to fluctuations and decreases sharply during storage. In general, in terms of the set and absolute content of vitamins, whey is a biologically complete product.

Of the organic acids, lactic acid was found in serum, as well as citric, nucleic and volatile fatty acids - acetic, formic, propionic, butyric. Lactic acid is formed from lactose as a result of the vital activity of bacteria.

Under the action of proteolytic enzymes that are produced lactic acid bacteria, there is a breakdown of whey protein substances, for the inactivation of which it is necessary heat treatment at temperatures above 60 ° C. In addition, lipase and phosphorylase enzymes should be considered, the presence of which can lead to a bitter taste in serum. Particular attention should be paid to the enzyme lactase, which is involved in the hydrolysis of lactose.

Milk whey contains gases - carbon dioxide, nitrogen and oxygen. The amount of gases in whey is slightly less than in whole milk, due to heat and machining milk in the production of cottage cheese, cheese and other products. During storage of whey, especially when it is littered with extraneous microflora, the amount of gas can increase sharply, which leads to increased foaming in the whey.

The composition of whey indicates that it is a complete type of raw material; in terms of their biological value, they are practically not inferior to whole milk. However, the energy value of whey is 3.5 times lower than that of whole milk. This determines the advisability of using milk whey in the production of products. diet food... Data on energy value serums are given below.