Organoleptic indicators of the quality of bread and bakery products. Sanitary examination of bread

27.09.2020

Organoleptic assessment is carried out to establish the conformity of the organoleptic indicators of the quality of products to the requirements of regulatory and technical documentation. Organoleptic assessment is carried out to determine indicators of appearance, color, taste, aroma, consistency, etc. through the senses. A tasting committee in the amount of at least five people is created on the basis of the selection of tasters, taking into account their individual sensitivity and ability to establish specific differences in color, taste, smell, aroma.

With the organoleptic method, the quality of bread is assessed using the human senses: sight, smell, taste, touch, hearing.

The following parameters of a cookie are determined by the organoleptic method: appearance, condition of packaging, marking, shape, surface condition, color, taste, smell, consistency, appearance in a fracture. The organoleptic method is distinguished by its simplicity and speed of determination, but it is subjective in nature, which makes the quality assessment inaccurate. In addition, the organoleptic method does not give a complete picture of the quality of the cookie, its chemical composition, presence or absence of harmful substances. In the process of tasting, with the help of the senses, not only the taste is determined, but also the appearance, smell, color, consistency of the product.

In terms of organoleptic characteristics, rye, rye-wheat and wheat-rye bread must meet the requirements specified in Table 6.

Indicator name	Characteristic
Appearance:
shape: hearth	Round, oval or oblong-oval, not vague, without imprints, with slightly pointed ends in Minsk bread
Shaped	Corresponds to the bread form in which the baked goods were made, without side outlets
surface:
Shaped	With gloss at Borodino bread; smooth, without large cracks and explosions in other types of bread; with the presence of caraway seeds or anise in rye custard bread, coriander, caraway seeds or anise in Borodino bread; the presence of a seam from the divider-stacker is allowed
Podovoy	No major explosions. Glossy in bread from Minsk and Riga, rough in other types of bread; pricks, cracks, powderiness of the upper and lower crusts are allowed. For baked bread "Viru", one transverse cut at both ends or pricks is allowed. Peeling of the crust from the crumb is not allowed in pan and hearth bread
	Dark brown for Borodino bread; from light brown to dark brown for other types of bread
Crumb condition:
Baked	Baked, not sticky, not wet to touch, elastic. After light pressure with your fingers, the crumb should return to its original shape. Custard bread has a crumb with a little stickiness
	No lumps and traces of impurities
porosity	Developed, without voids and seals. For custard bread, the crumb is slightly thickened
	Peculiar to this type of product, without any foreign taste. At the canteen, near Moscow, Riga and baked bread "Viru" is slightly sour sweet Borodino bread has a sweetish
	Peculiar to this type of product, without foreign smell. At rye custard bread, Moscow, Borodino, Minsk, Riga, baked "Viru" - with a light aroma of caraway, anise or coriander

Notes:

1. Large cracks are considered to pass through the entire upper crust in one or more directions and have a width of more than 1 cm.
2. Large explosions are considered to cover the entire length of one of the sides of the pan bread or more than half of the circumference of the hearth bread and have a width of more than 1 cm in the pan bread and more than 2 cm in the hearth bread.
3. It is allowed to produce round-shaped Minsk bread when it is produced on complex mechanized lines equipped with round-shaped dough pieces transplants.

To determine the organoleptic indicators of the quality of rye-wheat bread, we took two samples from one manufacturer:

1. Rye - wheat bread "Korenskoy" molded in packaging, manufactured by JSC "Kurskkhleb", Russia, Kursk, st. Dmitrova, 100. (TU 9113-001-00348097-05)
2. Bread rye - wheat "Stolichny" molded in packaging, manufactured by JSC "Kurskkhleb", Russia, Kursk, st. Dmitrova, 100. (GOST 26984-86)

The study of organoleptic indicators of the quality of cookies is presented in (Appendix 1).

On the basis of the tasting card, the analysis of the arithmetic mean and standard deviation was carried out, the results of the analysis were drawn up in the form of a protocol of the tasting commission (Appendix 2).

Results of Tasting evaluation of Korenskoy molded rye-wheat bread in packaging (TU 9113-001-00348097-05).

Indicators						Average mark.
Appearance
Surface

Taste and smell
Crumb condition
Points total

Results of the Tasting assessment of rye-wheat bread "Stolichny" molded in packaging (GOST 26984-86)

Indicators						Average mark.
Appearance
Surface

Taste and smell
Crumb condition
Points total

The results of the tasting evaluation showed that the greatest amount of points was scored by rye-wheat bread "Stolichny" molded in packaging, manufactured by JSC "Kurskkhleb", Russia, Kursk, st. Dmitrova, 100. (GOST 26984-86) Since it had an appearance corresponding to the bread form in which the baking was made, without side outlets, the crumb is baked, not sticky, elastic, without lumps and traces of trade. Taste corresponding to this type of product without foreign odors.

To determine the organoleptic indicators of the quality of rye bread, we took two samples from one manufacturer:

1. Bread rye "Zavarnaya" molded in packaging, manufactured by JSC "Kurskkhleb", Russia, Kursk, st. Dmitrova, 100. (GOST 2077-84)
2. Bread rye "Moskovsky" molded in packaging, manufactured by JSC "Kurskkhleb", Russia, Kursk, st. Dmitrova, 100. (GOST 2077-84)

The study of organoleptic indicators of the quality of cookies is presented in (Appendix 3).

Molded rye bread "Zavarnaya" in packaging, manufactured by JSC "Kurskkhleb", Russia, Kursk, st. Dmitrova, 100. (GOST 2077-84)

Indicators						Average mark.
Appearance
Surface

Taste and smell
Crumb condition
Points total

Molded rye bread "Moscow" in packaging, manufactured by JSC "Kurskkhleb", Russia, Kursk, st. Dmitrova, 100. (GOST 2077-84)

The results of the tasting evaluation showed that the greatest amount of points was scored by bread rye bread "Zavarnaya" molded in packaging, manufactured by JSC "Kurskkhleb", Russia, Kursk, st. Dmitrova, 100. (GOST 2077-84)

Since it had an appearance corresponding to the bread form in which the baking was made, without lateral protrusions, the crumb is baked, not sticky, elastic, without lumps and traces of promises. Taste corresponding to this type of product without foreign odors.

The hygienic assessment of bread is given on the basis of organoleptic examination and determination of moisture, porosity and acidity. If necessary, a microbiological analysis of the bread is carried out and the determination of poisonous and foreign inclusions in it.

Organoleptic characteristics of bread

The surface of the bread should be smooth, without cracks and tears, swelling, burnt spots, foreign inclusions. The upper crust is not allowed to lag behind the crumb. The thickness of the crusts should be no more than 0.5 cm.If the upper crust is very thin and lags behind the crumb, then the oven temperature was too high, the crust formed quickly, and gases (carbon dioxide, water vapor and alcohol) expanding in a heated space, trying to escape outward, raised the top crust. On the contrary, a thick crust and the presence of hardening (a layer of unbaked dough in bottom crust) - signs of insufficient oven temperature. The color of the crust should be uniform, brown-brown for rye bread, light or dark yellow for wheat bread. The crumb in the cut should be homogeneous (there should be no lumps of unmixed dough or old bread), finely porous and, with light pressure with a finger, should quickly take its original shape. The taste should be pleasant, without bitterness and foreign aftertaste. When chewing, there should be no crunch on the teeth and mineral impurities.

The smell of bread should be pleasant, fragrant, characteristic of this type of bread. A musty smell is a sign of the poor quality of the flour from which the bread is baked.

Determination of porosity

The porosity of bread is an indicator of the quality of the bread baked and the good quality of the flour from which it is baked. The porosity of the bread improves the organoleptic properties of the bread and promotes better absorption of nutrients. Porosity is understood as the ratio of the pore volume of the crumb to the total volume of the crumb, expressed as a percentage.

To determine the porosity of bread, a Zhuravlev device is used, which consists of the following parts: a metal cylinder with a pointed end on one side; wooden sleeve; wooden or metal tray with a transverse wall.

A piece 7-8 cm long is cut out from the middle of the bread, a notch is made from its crumb with a cylinder of the device (with a rotational movement, after having lubricated its sharp edge vegetable oil). The crumb-filled cylinder is placed on the tray so that its rim fits into the slot provided in the tray. Then the bread crumb is pushed out of the cylinder by about 1 cm and cut off at the edge of the cylinder with a sharp knife. The cut piece is removed, and the remaining cylinder is pushed out by the sleeve to the wall of the tray and cut off at the very rim of the cylinder. The volume of the cylinder crumb is 27 cm 3.

To determine porosity wheat bread do 3, and for rye bread and bread from a mixture of flour - 4 cylindrical cavities. The prepared recesses are weighed at the same time and the porosity is calculated by the formula:

X is the required percentage of porosity,

B - the total volume of bread dumps,

a is the weight of the grooves in grams,

b - density of non-porous mass.

The density of the non-porous mass (b) is taken for rye bread, wheat bread made from wallpaper flour and rye wheat bread - 1.21; wheat of the second grade - 1.26, wheat of the highest and first grade - 1.31.

Indicator name	Characteristic
Appearance: hearth surface	Corresponds to the bread form in which the baked goods were made, with a slightly convex upper crust, no lateral protrusions Rounded, oval or oblong - oval, not diffuse without imprints. Allowed when working on tunnel kilns with mechanized transfer of 1 - 2 small slip. Free from large cracks and tears, with or without punctures or cuts as per the technical description. The presence of a seam from the divider is allowed
	Light yellow to dark brown (on top crust)
Crumb condition: baked porosity	Baked, not damp to the touch. Elastic, after light pressure with your fingers, the crumb should take its original shape. No lumps and traces of impurities. Developed without voids and seals.
	Peculiar to this type of product, without any foreign taste.
	Peculiar to this type of product, without foreign smell.

Crumb condition.

The bread should be well baked, not sticky and not wet to the touch, without lumps, voids and traces of impurities, with uniform porosity, elastic.

The crumb, after lightly pressing with your fingers, should take its original shape, be fresh.

The taste and smell should be characteristic of this type of bread.

When assessing physical and chemical indicators, the moisture content of the crumb, acidity and porosity are determined.

The moisture content is provided by the standard, taking into account the type, baking method and recipe of bread: for simple rye and custard bread - no more than 51%, for wheat bread made from wallpaper flour - no more than 48%, hearth products have a lower moisture content than molded ones. Increased humidity reduces nutritional value bread, impairs its taste and shortens the shelf life. As a rule, the higher the flour grade, the lower the bread moisture rate.

The acidity of bread is due to the way the dough is prepared and the type of flour. Acidity affects taste properties of bread. Not enough or too sour bread tastes bad. This indicator is used to judge the correctness of the technological process.

Table 6 Physical and chemical parameters of wheat bread

Rye products cooked with sourdough have a higher acidity (up to 12 °) than wheat products cooked with yeast, and their acidity does not exceed 4 °.

The state of the crumb of the products is characterized by its baking, porosity, elasticity and freshness. For baked products, the crumb is dry, non-sticky, not moist to the touch, without lumps and traces of impurities, elastic, impure and not crumbly. Porosity is objectively defined as the ratio of the pore volume of the crumb to the total volume of the crumb, expressed as a percentage.

The higher the porosity of the product, the longer they retain their freshness and are better absorbed by the body. Well-loosened bread with uniform fine thin-walled porosity is better impregnated with digestive juices and therefore more fully absorbed. The crumb with good elasticity in cooled bread quickly takes on its original shape after pressing.

Fresh products have a dry crust with an even surface, the crumb is uniform, elastic, soft, taste and smell characteristic of the name of the product, without signs of bitterness, foreign tastes and odors.

The safety indicators of bread products must correspond to the levels of toxic elements, microtoxins, pesticides, radionuclides, the standards of the Office.

Table 7 Safety indicators of bread and bakery products

Bread defects are caused by various reasons: the quality of the main and auxiliary raw materials, violation of its dosage and technical process, careless handling of bread after baking.

Distinguish between defects in appearance, crumb, taste and odor defects.

Defects in appearance - irregular shape of bread, cracks, tears on the crust, burnt or pale crust, lack of gloss on it.

Incorrect shape of products, which can be when using flour with a low quality of gluten, with improper shaping and insufficient or excessive proofing of the dough.

Cracks and tears on the crust are formed when the bread is insufficiently proofed, when the temperature is too high, or there is no steam in the oven.

A burnt or pale crust is caused by the oven temperature during the baking process. Dark color or thick rind appears with increasing temperature or baking time; an increased amount of sugar in the dough causes a dark color of the crust, a decreased amount - a pale one.

During transportation and storage, bread can be deformed as a result of careless or tight packing of hot products into containers.

Crumb defects - impurities, lagging of the crust from the crumb, hardening, crumbling, uneven porosity and impermeability of the crumb. Crumb defects occur when flour made from sprouted grains is used, or when too much water is added, resulting in an uncooked and sticky crumb.

The quality of bread is determined by a combination of various properties, which can be divided into five groups (Fig. 1). The role of each of these groups is the same. Obviously, when assessing the quality of bread, it is impossible to take into account all of its indicators. It is not about measuring quality in general, but only a set of indicators reflecting the consumer value of a product.

Fig. 1 Properties that determine the quality of bread

The consumer first of all pays attention to the organoleptic properties - appearance, taste, aroma and freshness of products. The quality is much broader and includes nutritional value and harmlessness, conditions and shelf life and other characteristics of products.

The quality of the bread, as well as the main methods of its assessment, are regulated by standards. The quality of the bread is determined on the basis of the average sample taken in accordance with the standard methodology from each batch of bread in terms of organoleptic and physicochemical indicators.

From the organoleptic indicators in bread, the following is determined: appearance, crumb condition, taste and smell, which must meet the established requirements (Table 4).

The appearance of the bread is assessed by its shape, surface condition, color, as well as by the absence of crust defects. The shape should be correct, corresponding to a certain type of bread: for a tin - with a slightly convex top crust, no sagging, not mint; at the hearth - not blurry, not flat, not wrinkled, without protrusions and imprints. Wrinkled or deformed products due to careless handling are not allowed for sale.

The surface of the products should be smooth, shiny, without contamination, large explosions (cracks that cross the crust and have a width of more than 1 cm are considered large cracks, large explosions are explosions that cover half or more of the bread circumference with a width of 1-2 cm).

The rind color should not be pale and uniform. Wheat high-quality bread - from golden yellow to light brown. Products should not be burnt. For many types of bread, the thickness of the crusts is also standardized (for wheat bread, up to 1.5-3 mm).

The condition of the crumb is an important indicator of the quality of bread, indicating the quality of the raw materials used, the correctness of the technological process and determining the degree of digestibility. The state of the crumb of bread is characterized by its bakedness, blend, porosity, elasticity and freshness.

The taste and aroma of the bread should be pleasant, corresponding to the given type of product. The taste of the bread should be without any signs of bitterness, without any aftertaste and without crunching from mineral impurities. Depending on the type, variety and recipe of products, the taste of bread has significant differences. to determine the taste of five products, slices are cut with a thickness of 6-8 mm, a sample of 1-2 g is bite off from the upper, lower and side crusts and crumb, chewed and kept in the mouth for 3-5 seconds. The taste of the sample is compared with the description in the standards.

The smell of bread should also correspond to the given type or variety, without musty and other foreign odors. The smell is determined by deep breathing of air 2-3 times from a large surface of a whole t cut product immediately after cutting.

Table 4. Organoleptic indicators wheat bread

Indicator name

Characteristic

Appearance:

molded

hearth

surface

Corresponds to the bread form in which the baked goods were made, with a slightly convex upper crust, no lateral protrusions

Rounded, oval or oblong - oval, not diffuse without imprints. Allowed when working on tunnel kilns with mechanized transfer of 1 - 2 small slip.

Free from large cracks and tears, with or without punctures or cuts as per the technical description. The presence of a seam from the divider is allowed

Light yellow to dark brown (on top crust)

Crumb condition:

baked

porosity

Baked, not damp to the touch. Elastic, after light pressure with your fingers, the crumb should take its original shape.

No lumps and traces of impurities.

Developed without voids and seals.

Peculiar to this type of product, without any foreign taste.

Peculiar to this type of product, without foreign smell.

When assessing physical and chemical indicators, the moisture content of the crumb, acidity and porosity are determined, less often - the content of sugar and fat, table salt, the belonging of bread to one type or another, depending on the type of flour. Recently, great importance is attached to sanitary and hygienic indicators: the presence of salts of heavy metals, radionuclides, the determination of microbial contamination. Physicochemical indicators characterize the strict observance of the recipe and the technological process by bakery enterprises, as well as the sanitary impeccability of bread.

Increased moisture reduces the nutritional value of bread, impairs its taste and shortens its shelf life. As a rule, the higher the flour grade, the lower the bread moisture rate.

Acidity affects the taste of the bread. Not enough or too sour bread tastes bad. This indicator is used to judge the correctness of the technological process.

Table 5. Physical and chemical parameters of wheat bread

The safety indicators of bread products must correspond to the levels of toxic elements, microtoxins, pesticides, radionuclides, the standards of the Office.

Table 6. Safety indicators of wheat bread

1.4 Defects of bread and its falsification.

Bread defects are caused by various reasons: the quality of the main and auxiliary raw materials, violation of its dosage and technical process, careless handling of bread after baking. There are defects in appearance, crumb, taste and smell.

To defects appearance include:

irregular shape - obtained if the bread is baked from non-fermented or fermented dough or if the dough is not heated evenly during baking;

surface defects - lack of crust, large cracks, dark crust, appear when the dough is insufficiently broadened or when the temperature is too high, or when there is no steam in the oven.

To defects crumb relate:

impurities - these are areas of the crumb containing flour, pieces of salt, obtained as a result of a violation of the dough kneading regime;

hardening - a non-porous wet crumb layer located near the bottom crust; as a result of settling bread on a cold surface, when planting in an insufficiently heated oven;

sticky crumb - when using flour from sprouted and frosty grains, short baking time.

Defects taste and aroma- the presence of a crunch when chewing, the presence of impurities, the use of fermented dough.

Due to the high humidity, bread quickly deteriorates, it is a medium for the development of microorganisms.

Potato disease — caused by a bacterium called a potato bacillus. The pulp acquires an unpleasant odor and turns into a dark, viscous mass.

Cretaceous disease - occurs when bread is stored in plastic bags. It spreads as dry, white patches; such bread is not used for food.

Let's consider the main types of counterfeiting of bread and bakery products found in the Russian markets and used to deceive the buyer.

Assortment falsification bread is due to the substitution of bread made from one type of flour to another. The most common assortment falsification of bread is the sale of products made from 1st grade flour under the guise of bread made from premium flour. It is possible to distinguish such a fake by color, but a more accurate conclusion can be made on the basis of physical and chemical indicators: the content of fiber, pentosans, calcium, phosphorus, iron, which can only be carried out by an experienced expert on the instructions of a representative of consumer protection authorities.

Qualitative falsification bread can be achieved by the following methods: increased water content; adding other types of flour; introduction food additives- flour improvers; replacing yeast with chemical leavening agents; introduction food colors; underinvestment of valuable components (oil, eggs, sugar, etc.) provided for by the recipe; replacement of expensive valuable components with cheaper ones (margarine with vegetable oil, etc.); non-observance of technological parameters of bread production; adding preservatives, antibiotics.

Quantitative falsification bread (underweight) is a deception of the consumer due to significant deviations in the parameters of the goods (weight), exceeding the maximum permissible deviations.

Information falsification bread is a deception of the consumer with the help of inaccurate or distorted information about the product. This type of falsification is carried out by distorting information in shipping documents, labeling, and advertising of goods. The substitution of certificates of conformity and accompanying documents can also be carried out.

Thus, there are many ways to hide defects in bread and sell a counterfeit product, so the buyer should carefully examine the product before purchasing it.

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Home / For catering enterprises / Merchandising food products/ Physicochemical indicators of the good quality of bread

Physical and chemical indicators of the good quality of bread

The main physical and chemical indicators characterizing the good quality and nutritional value of bread include moisture, acidity and porosity, which must meet the requirements of GOST.

A change in the acidity and moisture content of bread towards an increase in hygienic terms is undesirable, since an increase in the content of moisture and organic acids deteriorates the taste properties and reduces the nutritional value of the bread.

Eating bread with high acidity, in addition, can cause exacerbations in persons suffering from gastrointestinal diseases (hyperacid gastritis, etc.). Moisture bread at laboratory research determined by drying. Humidity different varieties bread is 43-51%.

Determination of acidity is based on the extraction of organic acids from a sample of bread and their subsequent titration with an alkali solution.

The acidity of bread is expressed in degrees. The degree of acidity is taken as the number of milliliters of 1N alkali solution used to neutralize the acids contained in 100 g of bread crumb. The acidity of the bread should not exceed 2-12 ° T.

The porosity of bread is the volume of pores contained in 100 volumetric units of crumb. Porous bread is easy to digest, as it is well soaked in the gastrointestinal tract with digestive juices.

The porosity is higher in wheat breads, which undergo alcoholic fermentation during the manufacturing process.

In this type of fermentation, yeast enzymes break down carbohydrates to form carbon dioxide, which loosens the dough, giving it a foamy structure. Under the influence of the high temperature of the baking oven, the pore walls, consisting of proteins, curl up, which ultimately gives a special splendor to the bread.

The porosity of the highest varieties of wheat bread can reach 75% and more, while in rye bread made from wallpaper it rarely exceeds 55%. Consequently, the porosity of bread is a sign that increases its nutritional value. The porosity of bread can be determined using the Zhuravlev device with subsequent calculation according to the appropriate formulas and tables, which take into account the data of the mass and volume of several grooves of the bread crumb.

Bread with high humidity, acidity and low porosity is non-standard and needs to be processed: dried on crackers, used for cooking bread kvass or returns to the bakery, where it is soaked and added in a certain amount to the dough for baking inferior types of bread.

Delayed stale bread.

At present, along with the usual forms of bread, the so-called delayed staling bread is used, that is, with an extended shelf life. An increase in the shelf life without significant organoleptic changes is achieved in various ways. For example, the inside of a cardboard box is lined crosswise with two sheets of wrapping paper, after which hot bread is placed in it immediately after baking and immediately covered with paper and box valves.

Analysis of physical and chemical indicators of the quality of bread

The seams of the box are sealed with kraft paper tape. When placing hot bread in a box, self-sterilization takes place, and bread prepared in this way can remain unchanged (stale and mold) for 10-12 days. If before laying the bread, 40-50 g is poured onto the bottom of the box mustard powder, then the shelf life of bread is increased to 20 days.

In the second method, bread, baked in the usual way and packed in a five-layer casing consisting of food parchment, aluminum foil, cellophane and thick wrapping paper, is sterilized.

The bread is sterilized for 4-4.5 hours at 100-110 degrees. After that, the packaged bread is dipped in molten paraffin.

After such processing, bread withstands storage for 2-5 months without significant changes.

The third method, more economical and productive, consists in the fact that loaves of bread are dipped for 2-3 seconds in rectified alcohol and then hermetically packed in a bag made of plastic wrap.

Bread processed in this way does not stale or mold up to 4 months.

With prolonged storage of delayed staling bread. a slight decrease in orgaioleptic properties is allowed: a wrinkled surface with minor cracks, a slight concavity of the lateral crusts, crumbness of the crumb, a slight increase in acidity.

Restoration of many of the original properties of such bread can be achieved by heating the loaves, freed from packing, in the oven for 1 -1! / 2 hours.

Canned bread... Collectives of people separated for a long time from the bread supply bases (members of the expedition, fishermen of flotillas on a long voyage) are sometimes provided with canned bread.

Canned bread is obtained by placing the dough in a tin can, pre-oiled with vegetable oil (half). After some exposure, when, as a result of fermentation, a piece of dough fills 80% of the volume of the jar, it is closed with a lid, and the jar is rolled up. The hermetically sealed jar is autoclaved.

At the same time, baking and sterilization of bread take place at the same time.

Canned bread can be stored for more than a year. It is easily removed from the can, has a corresponding shape, a smooth surface without tears and cracks, evenly colored in yellow or light yellow. The ends of the bread are flat or slightly spherical. Meat consistency, smell and taste are usual.

Calculate porosity using the formula: X = (V - M / P) · 100 / V,%, where X is porosity,%; M is the mass of the bread crumb sample, g; P is the density of the mass of this type of bread without pores, g / cm2; V is the volume of the crumb sample together with the pores (27 cm2).

To assess the porosity of the bread, comparing with the norms.

3. Determination of the acidity of bread. The acidity of bread (expressed in degrees) is equal to the volume of 1N NaOH solution used to neutralize acids (acetic and lactic) in 100 g of bread. Weigh 25 g of bread, grind, place in a 250 ml flask.

Add 50 ml of distilled water and rub the crumb with a glass rod until smooth. Add 150 ml of distilled water to the mixture (total volume of water 200 ml), close the flask with a stopper, shake vigorously for 2-3 minutes and leave to settle for 10 minutes.

Filter the resulting mixture through cheesecloth. Take 50 ml of the filtrate into a 100 ml flask, add 2-3 drops of 1% phenolphthalein and titrate with 0.1 N NaOH solution until a persistent light pink color appears.

Calculate the acidity of bread in degrees using the formula: X = V · × 4 · × 4/10 = 1.6 · V, where X is acidity, º; V is the volume of 0.1 N alkali solution used for titration of acids in the test sample of bread, ml. To assess the acidity of bread, comparing with the norms.

Bacteriological examination no freshly baked bread.

In some cases, in order to detect contamination of bread with spore-bearing bacteria and mold fungi, spores are sown on nutrient media.

55. Canned food, preserves n concentrates, their importance in nutrition. Preservation methods, their hygienic assessment. Sanitary and hygienic examination of canned food.

Canned food- food products subjected to physical, chemical or biological processing in order to create conditions for the safe storage of the product by destroying microorganisms, destroying or inactivating enzymes, ensuring the absence of air access by sealing the package.

Canning allows you to increase the shelf life of the product; increase its nutritional value by removing inedible / low-edible parts of the product; improve the organoleptic properties of the product.

Physical methods of canning.Sterilization- processing of the product with high temperature (100-140 ° С) - has a bactericidal effect.

Boiling(100 ° C) has a stabilizing effect on microorganisms, and prolonged boiling has a bactericidal effect, however, high-temperature processing leads to denaturation of proteins, which reduces the nutritional value of protein products (milk, meat), destroys vitamin C (fruits, vegetables).

Frying provides a bactericidal effect on the surface of the product. Prolonged (repeated) heating of fats (oils) to high temperatures (≥1600) leads to the formation of toxic substances: alkyl, alkoxy and peroxy radicals, polymerizates that irritate the digestive tract, have a toxic effect on the liver, slow down the growth of children and adolescents, cause accelerated aging of the body, etc.

Lack of antioxidants (vitamin E) in food will exacerbate these symptoms. When roasting on charcoal, up to 50 μg of benzo (a) pyrenes (carcinogens) per kg of meat are formed from overheated fats (on an infrared source - 0.2-8 μg / kg). Systematic use Eating overcooked fats can lead to neoplasms in the gastrointestinal tract. V fried meat discovered 2-amino-1-methyl-6-phenylimidazopyridine, attributed to an exogenous factor of heart failure in non-vegetarians.

Pasteurization(heating to 60-70 ° C for 15-30 minutes, or 90 ° C for 30 seconds, or fractional pasteurization at 70 ° C with rapid cooling) ensures the death of vegetative cells of thermophobic bacteria, yeast and microscopic fungi (spores withstand prolonged boiling) ...

Cooling food product up to + 4 ... 0 ° C provides a bacteriostatic effect. Freezing- cooling the product to a temperature below the cryoscopic point of the product (meat -0.6 ... -1.2 ° C, milk -0.55 ° C, eggs -0.5 ° C, fish -0.6 ... -2 ° C) ... With deep freezing (-18 ... -25 ° C), the vital activity of microorganisms stops, enzymes become inactive, with prolonged deep freezing, a bactericidal effect takes place.

With rapid freezing, the structure of the tissues is not disturbed, and after slow thawing (defrosting) food juices and vitamins are preserved, the food has a natural look and taste. Freezing methods: wet method - irrigation with water or NaCl solution (for meat carcasses); v freezers with refrigerant (freon, ammonia); in plate freezers for 2-3 hours with a layer thickness of the product< 5 см; в «кипящем слое» за несколько десятков минут при пропускании холодного воздуха через слой орехов, мелких или резанных овощей, фруктов и пр.; погружением в хладагент (жидкий азот, двуокись азота, фреон) за несколько минут.

To preserve vitamin C and moisture in frozen fruits and vegetables, vacuum sealed packaging is used. Vegetables are stored throughout the year at -18 ° C, fruits - at -12 ° C.

Freezing is the most advanced, but energy-consuming method. Dehydration of the product leads to the death of vegetative forms of microorganisms due to an increase in the concentration of dry substances and osmotic pressure in the cells (spores persist). Methods: natural (drying fish and melons in the shade, drying fruits in the sun (apricots, prunes, raisins); artificial (drying in ovens, freeze drying or lyophilization). Drying in ovens with hot air destroys vitamins, proteins, caramelizes sugars.

For liquid and puree products ( powdered milk, mashed potatoes, instant coffee) use foam drying or freeze drying (spraying liquid from nozzles under a vacuum of 1 mm Hg.

Art. and at a low temperature), which preserves the nutritional value of the product. When pressing dehydrated products, concentrates. Ultrasonic sterilization at a wavelength corresponding to the size of bacterial cells, it has a bactericidal effect, but does not destroy the cells of the food product.

Shortwave ultraviolet radiation It is used to sterilize the surface of a solid product (cheese) or a transparent liquid (vegetable oils). Radioactive g-radiation used to sterilize meat from Trichinella, leads to fat oxidation, destruction of proteins and vitamins, caramelization of carbohydrates and the formation of free radicals, which reduces the nutritional value, creates mutagenic activity of the product and makes it impossible to further use the meat for food.

Biological conservation methods. At pickling cabbage, soaking apples, pickling cucumbers lactic acid bacteria ferment sugars with the formation of lactic acid, which at a concentration of> 0.7% has a preservative effect.

All of these methods also include the addition of salt. Storage conditions: 0 ... + 4 ° С.

Chemical methods of preservation. Chemical methods are based on the addition of preservatives to prevent the growth of bacteria, mold and yeast. The classic methods include salting, adding sugar, pickling, smoking and preserving.

Salt used in a concentration of 10-12% for meat, 14% for fish, 10% for tomato paste and is often used when fermented or dried. Sugar has a preservative effect at a concentration of> 60-65% (jam, jam) (in a hypertonic sugar solution, microbial cells undergo plasmolysis).

Pickling organic acids (acetic E260, citric E330, malic, etc.) are possible at a concentration of 1.2-1.8%.

Smoking(antiseptic - wood sublimation products - phenols, formaldehydes, creosote, polycyclic hydrocarbons and acetic acid) is used for meat, sausages and fish. Methods: cold (t≤24 ° С), hot (t> 24 ° С) and chemical smoking (the latter implies the use of a liquid concentrate of wood sublimation products).

When smoked, the products of sublimation of wood (including benzo (a) pyrene) with smoke settle on the surface of the product at a concentration of 2-8 μg / kg.

Bakery products

In the body, polycyclic hydrocarbons form epoxy compounds that react with guanine, thus inhibiting the replication of DNA in somatic cells. The constant consumption of smoked products is a risk factor for the development of cancer.

Preservation Is the canning of fish without sterilization in a spicy filling, where salt, acetic acid and spices (essential oils) act as preservatives.

Preserves are stored for up to 6 months at 0 ... + 5 ° С.

Date of publication: 2015-02-18; Read: 451 | Page copyright infringement

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Classification of bakery products

Bakery products

Bread is the name for products baked from dough loosening of the second is achieved biologically, that is, through fermentation. Fermentation can be initiated by either yeast or lactic acid bacteria. In the test from wheat flour the main type of fermentation is alcoholic, and in the dough made from rye flour or its mixture with wheat flour - lactic acid.

Fermentation in the dough can occur spontaneously, ᴛ.ᴇ. due to microorganisms entering semi-finished products along with raw materials, from the air or from equipment. This primarily concerns lactic acid bacteria. Yeast is specially introduced into semi-finished products from wheat flour.

In accordance with the current regulatory documentation, this group of food products includes: bread, bakery products, as well as products with low humidity (up to 19%) - crackers, dryers, bagels, bagels, etc.

Bakery products, in turn, are subdivided into bakeries proper, as well as small-piece and butter products. At the same time, the products are subdivided according to the type and grade of flour, they are classified based on the weight, especially the recipe and other characteristics.

Bread refers to products of any shape weighing more than 500 g, bakery products include products weighing 500 g or less.

Small-piece products have a mass of 200 g or less. In the recipe for pastry, the total amount of sugar and fat should be 14% or more.

Baked bread occupies a special place in the diet of the population. Unlike many other foods, bread is consumed daily and everywhere. The daily consumption of bread per consumer ranges from 200 to 400 ᴦ.

In Russia, per capita bread consumption is about 102 kg per year, which is slightly less than in the USA (125 kg).

The nutritional value of the bread is quite high.

QUALITY INDICATORS OF BREAD AND BAKERY PRODUCTS

On average, bread contains 5.5-9.5% proteins, 0.7-1.3% fats, 1.4-2.5% minerals, 39-47% water. In donut products and breadcrumbs, WATER is much less (8-17%), the proportion of proteins and digestible carbohydrates, respectively, is higher (9 and 70%). The energy value of 100 g of the product is 200-350 kcal. When assessing the nutritional value of bread, it must be borne in mind that the higher the grade of flour, the lower the moisture content of the bread, the content of proteins, digestible carbohydrates and, accordingly, energy value, but the amount of vitamins and other biologically active substances decreases.

Range bakery products in Russia are distinguished by a significant variety.

At the same time, 95% of the total production volume is made up of products of 100-140 names.

The vast assortment of bakery products, numbering approximately 1000 varieties and varieties, can be divided into the following groups:

‣‣‣ by the type of flour - rusty bread, wheat bread, from a mixture of rusty and wheat flour;

‣‣‣ by baking method - mold and hearth;

‣‣‣ in shape - loaves, rolls, braids, etc .;

‣‣‣ according to the recipe - just bread made from flour, water, salt and yeast (or sourdough); improved - with the addition of 3-6% (by weight of flour) sugar or molasses to the main raw materials, and in some varieties - fat (no more than 7%) and spices; butter - with a large amount of SD06NI (7-30% sugar, 7-15% fat, etc.);

‣‣‣ by the method of cutting and baking - by weight and piece;

‣‣‣ by appointment - ordinary and dietary.

Bread from a mixture of rye and wheat flour is baked from all types of rye flour and wheat 1, 11 varieties and wallpaper.

The addition of wheat flour improves the structure of the bread, and mixing two types of flour in different ratios allows you to get products that are different in taste, volume, crumb porosity, and appearance.

Bread is produced with simple and improved bread, hearth and molded, weight and piece.

To the recipe plain bread most often it includes peeled rye flour in combination with wheat wallpaper (Ukrainian), wheat II grade (Ukrainian new), wheat I grade (Darnytskyi), there are other recipe options, for example, 30% rye wallpaper flour and 70% wheat wallpaper.

Improved varieties of rye-wheat bread are baked in a wider range: Borodinsky ( Rye flour wallpaper - 8O%, wheat grade 11 - 15, molasses - 4%.

cumin or coriander), Russian, Riga, Minsk, table.

From wheat flour produce simple and improved bread, bakery and pastry products. Bread from wheat wallpaper, of the highest, 1 and 11 grades, is referred to as simple bread.

Improved bread (krasnoseyelsky, mustard) is usually cooked with dough, sugar (3-6%) and fat (2-7%) are added.

Bakery products baked from flour of the highest, G and P grades.

These are hearth piece products in the form of loaves, rolls, buns, khal, plait, whitewash, rolls weighing 500 g or less, the recipe of which includes less than 7% fat and 7% sugar.

Butchery products contain 10-26% sugar, 7-20% fat, 0.8-16% eggs, jam, jam, icing sugar and etc.

It is customary to distinguish between ordinary buns, amateur products, simple and curly Vyborg buns.

Bakery products are assessed by organoleptic (appearance, crumb condition, taste and smell) and physicochemical indicators (moisture, acidity, porosity).

Shape of bread and bread products should be correct, crust without cracks, tears, tightly adjacent to the crumb.

Coloring from golden yellow to dark brown, based on the type of product. The crumb is well-baked, elastic, non-crumbling, non-sticky, uniformly porous, without voids.

The taste and smell of bread and baked goods must be characteristic of each grade. Taste of bitterness, excessive acidity, salinity, moldy smell and other extraneous tastes and odors are not allowed - When chewing bread, there should be no crunching on the teeth.

Bread moisture normalized by standards for the upper limits - from 34 to 51%.

High humidity reduces the nutritional value of bread, impairs its taste and shortens its shelf life. As a rule, the higher the flour grade, the lower the bread moisture rate.

Acidity of bread expressed in degrees, ᴛ.ᴇ.

number of milliliters 1 N. alkali solution consumed for titration of 100 g of the product. Products made from high-quality wheat flour have an acidity of no more than 2-4 degrees, wheat wallpaper - no more than 7 degrees. Acidity affects the taste of baked goods.

Porosity of bread characterizes the proportion of air in the total volume of the product and is limited to the lower limits.

The higher the porosity of the products, the longer they remain fresh and better absorbed by the body. The porosity of shaped wheat bread made of premium flour must be at least 72%.

When assessing the quality of bread, products with defects in appearance, internal structure of the crumb, taste and smell die off. Defects in appearance include an irregular shape, a pale or burnt crust, peeling of the crust from the crumb, etc. Such defects appear due to improper manufacturing process, poor flour quality or poor transportation conditions.

To defects crumb include its stickiness, the presence of large voids, uneven porosity.

Taste and odor defects arise for various reasons.

Bread from fermented dough is sour, from unfermented dough, unfermented.

In some cases, the so-called potato, or stringy, bread disease, caused by the development of thermophilic bacteria, may appear.

Bakery products are sold both packed and unpacked.

The packaging of bakery products must contain:

product name; the name and location of the manufacturer, his trademark; the mass is not; product composition; the nutritional value; storage conditions; date of manufacture; shelf life; shelf life - for products with low humidity; name of the regulatory document; product certification information.

Unpackaged items must be accompanied by a leaflet.

Sanitary examination of bread

Organoleptic characteristics of bread

The surface of the bread should be smooth, without cracks and tears, swelling, burnt spots, foreign inclusions.

The upper crust is not allowed to lag behind the crumb.

Bread quality indicators

The thickness of the crusts should be no more than 0.5 cm.If the upper crust is very thin and lags behind the crumb, then the oven temperature was too high, the crust formed quickly, and gases (carbon dioxide, water vapor and alcohol) expanding in a heated space, trying to escape outward, raised the top crust. On the contrary, a thick crust and the presence of hardening (a layer of unbaked dough at the bottom crust) are signs of insufficient oven temperature. The color of the crust should be uniform, brown-brown for rye bread, light or dark yellow for wheat bread.

The crumb in the cut should be homogeneous (there should be no lumps of unmixed dough or old bread), finely porous and, with light pressure with a finger, should quickly take its original shape. The taste should be pleasant, without bitterness and foreign aftertaste. When chewing, there should be no crunch on the teeth and mineral impurities.

The smell of bread should be pleasant, fragrant, characteristic of this type of bread.

A musty smell is a sign of the poor quality of the flour from which the bread is baked.

Determination of porosity

The crumb-filled cylinder is placed on the tray so that its rim fits into the slot provided in the tray. Then the bread crumb is pushed out of the cylinder by about 1 cm and cut off at the edge of the cylinder with a sharp knife.

The cut piece is removed, and the remaining cylinder is pushed out by the sleeve to the wall of the tray and cut off at the very rim of the cylinder. The volume of the cylinder crumb is 27 cm3.

To determine the porosity of wheat bread, make 3, and for rye bread and bread from a mixture of flour - 4 cylindrical grooves. The prepared recesses are weighed at the same time and the porosity is calculated by the formula:

NS
- the required percentage of porosity,

B - the total volume of bread dumps,

a is the weight of the grooves in grams,

b - density of non-porous mass.

The density of the non-porous mass (b) is taken for rye bread, wheat bread made from wallpaper flour and rye-wheat bread - 1.21; wheat of the second grade - 1.26, wheat of the highest and first grade - 1.31.

Organoleptic assessment of the quality of bakery products

Organoleptic assessment of food products, including bakery products, in assessing their quality is very important. The results of organoleptic analysis should be decisive in determining the quality of new products, in the development of new technologies for obtaining basic food products of the population.

The organoleptically determined indicators of the quality of bakery products include the appearance (surface condition, color and condition of the crust, the absence or presence of peeling of the crust from the crumb and the shape of the product), the condition of the crumb (freshness, bakedness). When assessing the porosity of a product, attention is paid to the size of the pores (small, medium, large), the uniformity of their distribution over the entire space of the crumb cut (uniform, sufficiently uniform, insufficiently uniform, uneven) and the thickness of the pore walls (thin-walled, medium-thick, thick-walled), the presence of voids and seals.

When assessing the smell, attention is drawn to the presence or absence of foreign, unusual and especially unpleasant odors in the product.

The taste is determined by chewing the crumb of the product. Attention is drawn to the presence of a taste that is not characteristic of a bakery product. The taste can be normal, sweet, sour, insipid, bitter, etc. Sometimes the product has foreign odors that affect its taste.

Conclusion: Sample 1 fully meets the requirements of GOST 27844-88. Sample 2 does not comply with GOST 27844-88 in terms of "promes" and "Porosity"

Determination of the quality of bakery products by physical and chemical indicators

In accordance with the requirements of the standards, the main physical and chemical indicators of the quality of bakery products are: moisture; acidity; porosity; mass fraction of fat; mass fraction of sugar; mass fraction of sodium chloride; for fortified products - the mass fraction of vitamins B (thiamine), B2 (riboflavin), PP (nicotinic acid).

In this work, the moisture, acidity and porosity of the Metropolitan loaves will be determined.

Moisture in bakery products

The moisture content of the bakery product is determined: to calculate the yield; to check compliance with the mode of the technological process, recipes; for accounting of energy value. With an increase in the moisture content of the product, its yield increases, the energy value decreases, and such quality indicators of the product as the shape, appearance (bottom products may blur, and for molded products, the upper crust may be flat, less convex), and the color of the crust. crumb structure, etc.

You can get an accurate idea of the moisture content of bread by drying a portion of the product to constant weight at 100-105 ° C. The standard for bakery products provides for an accelerated method for determining the moisture content (GOST 21094-75) of not whole bread, but only its crumb.

Moisture determination method.

In preparation for analysis, the laboratory sample is cut approximately in half and a slice 1--3 cm thick is cut from one part.The crumb is separated from the crusts at a distance of 1 cm.The mass of the isolated sample should be at least 20 g.

The prepared sample is quickly and thoroughly grinded with a knife, grater or mechanical grinder, mixed and two weighed portions are immediately taken. If the sample consists of a piece of bread, then the windy part with a thickness of about 0.5 cm is first cut off from it.

Determination of the mass fraction of moisture in the crumb of bread is carried out in electric drying cabinets with thermostats. Drying is carried out in metal cups 2.0 cm high and 4.5 cm in diameter.

In pre-dried and weighed weighing bottles with a lid, weigh 5 g of bread crumb with an accuracy of ± 0.01 g. The cabinet should be heated to a temperature of 140-145 ° C. and the temperature in the cabinet drops rapidly, usually below 130 ° C. Within 10 minutes, it is brought to 130 ° C. and at this temperature, drying is continued for 40 minutes. (the deviation should not exceed ± 2 ° С).

If the required temperature (130 ° C) in the drying cabinet is established in 1-2 minutes, it is recommended to dry in it within 50 minutes from the moment the samples are placed in the cabinet.

After drying, the weighing bottles are closed with lids, cooled in a desiccator for 15-20 minutes and weighed. It is impossible to leave the bottles in the desiccator for more than 2 hours, since the weighed portions will absorb moisture.

From the difference in the weighed portion before and after drying, the mass of the evaporated moisture is determined and the mass fraction of moisture (%) is calculated with an accuracy of ± 0.5%.

Moisture is calculated by the formula:

W = 100 (m1- m2) / m,

where m1 is the weight of the weighing bottle before drying, g;

m2 is the weight of the weighing bottle after drying, g;

m is the mass of the sample, g.

Porosity of bakery products

The porosity of a bakery product is understood as the ratio of the volume of the pores of the crumb to the total volume of the crumb, expressed as a percentage. The porosity of the product, taking into account its structure (pore size, uniformity, wall thickness), characterizes such an important property of the product as digestibility. Low porosity is usually inherent in products made from poorly fermented dough, with low humidity, etc.

The standard specifies what the porosity should be (a lower limit is given). So the porosity of rye, rye-wheat and wheat-rye bread should be at least 45-65%; wheat flour products - 54-74%, depending on the type of product and the baking method.

The porosity of bread is determined by Zhuravlev's method.

Determination method

A piece with a width of at least 7 - 8 cm is cut out from the middle of the product. Recesses are made from a piece of crumb at a distance of at least 1 cm from the crusts with a cylinder of Zhuravlev's device. The sharp edge of the cylinder is pre-lubricated with vegetable oil. The cylinder is introduced by rotating movements into the crumb of the bread.

The cylinder filled with crumb is placed on the tray so that the rim fits snugly into the slot in the tray. Then the bread crumb is pushed out of the cylinder by a wooden sleeve about 1 cm and cut off at the edge of the cylinder with a sharp knife. The cut piece of crumb is removed. The crumb remaining in the cylinder is pushed out by the sleeve to the wall of the tray and is also cut off at the edge of the cylinder.

To determine the porosity of rye bread crumb, four cylindrical cavities with a volume of 27 ± (0.5) cm3 each are made from the flour mixture and weighed simultaneously.

Processing of results:

P = 100 (V - m / p) / V,

where P is porosity,%;

V is the total volume of bread dumps, cm3;

m is the mass of the recesses, g;

p is the density of the non-porous crumb mass.

Acidity of bread

The acidity index of a bakery product characterizes its quality from the taste side. This indicator can also be used to judge the implementation of the rules for maintaining the technological process of preparing the product.

The acidity of bread is mainly due to the products obtained as a result of the fermentation of the dough. Acidity is expressed in degrees of acidity.

The degree of acidity (according to GOST 5670-96) is understood as the volume in cubic centimeters of a solution of the exact molar concentration of 1 mol / dm3 of sodium hydroxide or potassium hydroxide, necessary to neutralize the acids contained in 100 g of products.

The standard specifies what the acidity of the product should be. So, for rye bread, rye-wheat, wheat-rye (the upper limit is indicated), the acidity should be no more than 7.0-11.0 degrees, bakery products made of wheat flour - 2.5-4.0 degrees per depending on the type of product.

Determination method

The bread is cut in half in width and a piece weighing about 70 g is cut from one half, from which the crusts and subcrustal layer about 1 cm thick are cut off.

In a sample consisting of a part of the product, the wind-blown part is cut off from one side, making a continuous cut with a thickness of about 0.5 cm.Then a piece weighing about 70 g is cut off, from which the crusts and subcrustal layer with a thickness of about 1 cm are cut off.

The prepared pieces are quickly crushed and mixed.

Weigh 25 g of crushed bread crumb with an accuracy of + 0.01 g and place in a jar with a capacity of 500 cm 3. A volumetric flask with a capacity of 250 cm is filled to the mark with water at room temperature, about 1/4 of the water taken is poured into a jar of bread and rubbed well with a wooden spatula. Then the remaining water is added, the contents of the jar are vigorously stirred for 2 minutes and left alone at room temperature for 10 minutes. Then the contents are mixed again for 2 minutes and again left alone for 8 minutes. During this time, acid-reacting substances from the crumb of bread pass into the hood.

Then the settled layer of liquid is poured through a fine sieve or gauze into a dry glass. From the beaker, 50 cm of filtrate is pipetted into two conical flasks with a capacity of 100-150 cm3 each and titrated with 0.1 N sodium or potassium hydroxide solution with the addition of 2-3 drops of phenolphthalein until a faint pink color appears that does not disappear within 1 min.

The acidity of the crumb X (degrees) is calculated with an accuracy of 0.5 degrees. according to the formula:

where X is acidity, deg;

V is the volume of sodium hydroxide solution with a molar concentration of 0.1;

mol / dm 3 consumed for titration of the test solution, cm 3;

K - correction factor for the reduction of the solution used

sodium hydroxide to a solution with a concentration of 0.1 mol / dm 3.

organoleptic chemical bread fruit