Chemical analysis of chocolate. Analysis of Globus, Milka and Air chocolate revealed the true quality of the product. Characteristics of research objects

Municipal budgetary educational institution

Rozhentsovskaya Secondary School

Section: Chemistry

Experimental abstract project

“Chemical analysis of chocolate and its effect on human health”

The project was completed

8th grade students:

Kuklina Yulia,

Sirotkina Svetlana

Supervisor

chemistry-biology teacher:

Natalya Arkadyevna Maltseva

2016

With. Rozhentsovo

I. Introduction 3 pages

II. Theoretical part 3 – 7 pages.

-Literature review

-GOST No. 6534-69

-Chocolate classification

-The history of chocolate

Cocoa beans instead of coins.

A gift from the Aztecs.

-Chocolate storage

III. Experimental part 8 – 12 pages.

IV. Conclusion 13 -16 pp.

-The effect of chocolate on the body

-Questionnaire

-Applications of chocolate

Conclusions from the work

V. Appendix 17 p.

VI. References 18 pages.

I. Introduction

Currently, chocolate is one of the most common food products among people. In almost every store anyone can buy a bar of chocolate. But chocolate can be approached not only from a consumer, but also from a research point of view, by choosing it as an object of chemical analysis.

Relevance of the problem: We took this topic for the project: firstly, because we love sweets very much; secondly, the world of chocolate is very diverse, and I would like to find out whether the composition on the label really matches the contents; thirdly, I would like to find out whether it is harmful.

Objective of the project : explore the chemical composition of different brands of chocolate and study its effects on human health.

Research objectives:

Get to know different types of chocolate.

Study the chemical composition of different types of chocolate.

Conduct a qualitative analysis of the studied samples of chocolate products.

Compare their chemical composition.

Study the effect of chocolate on human health.

Conduct a survey among classmates about the dangers and benefits of chocolate.

Find out how chocolate is currently used in medicine and cosmetology.

Object of study : chocolate.

Subject of study : chemical analysis of the composition of chocolate.

Project type : group, long-term, interdisciplinary (chemistry and biology), experimental.

Forms for presenting project results : report, presentation.

II. Theoretical part

Literature review

Chocolate - (English Chocolate, French Chocolat, Spanish Chocolate) is a term denoting various types of confectionery products made using cocoa fruits. One of the most common confectionery products. It contains proteins, fats, carbohydrates, tannins, alkaloids caffeine and theobromine. It is prepared on the basis of cocoa products.

E thymology of the name: The word "chocolate" comes from "chocolatl", the name of a drink made from cocoa beans. In the Aztec language, "chocolli" means "bitterness" and "atl" refers to the water used to make the chocolate drink.

GOST No. 6534-69

According to state industry standard No. 6534-69, chocolate is:

taste and aroma clearly expressed, characteristic of this species

color from light brown to dark brown, for white chocolate – cream

form correct, without deformation, in the form of tiles, loaves, various shapes, both with and without a pattern

facial surface chocolate should be shiny, without sugar and fat bloom, in chocolate with milk - slightly dull, in chocolate with uncrushed additives the bottom side of the bar has an uneven surface

consistency should be hard, the structure should be uniform, the fracture should be matte, for porous chocolate – cellular

additions, not introduced in finely ground form, are evenly distributed in the chocolate mass.

Chemical composition of chocolate and cocoa beans

The shell of cocoa beans is not used in making chocolate, although this is sometimes the case. Cocoa shell contains in large quantities: mineral compounds, aromatic oils, ash 10%, fiber up to 15%, fat 3-5%, pentosans about 6%, pectin substances 4.8% in a low-fat substance.

Cocoa butter contains: triglycerides of saturated fatty acids - palmitic, oleic, stearic, alkaloids theobromine and caffeine, antioxidants (do not allow them to burn and settle), aromatic and tannin substances, which actually gives the taste and aroma of chocolate. The aromatic bouquet of chocolate is also formed thanks to the gradation of cocoa beans into noble and consumer grade. The former give chocolate a bright taste and aroma, the latter – bitterness, astringency, and acidity. Cocoa butter has seven polymorphic forms, one of which is very stable and allows chocolate to be stored for a long time. The secret is that at room temperature, cocoa butter solidifies itself, but melts in the mouth. Therefore, real chocolate should not contain any hardeners.

The average composition of cocoa beans is given in the table

Substances	Composition in %

Nitrogenous substances
Cellulose

Tannin (tannin) and coloring matter
Theobromine
Pentosans
Essential oils
Organic acids (malic, citric, oxalic)



Saccharides

Other minerals and salts

Chocolate classification

Depending on the processing method, chocolate mass is divided into dessert and ordinary. Dessert chocolate mass has high aromatic qualities and fine dispersion. It acquires these properties as a result of particularly careful and lengthy processing. Content Sahara it contains no more than 55%. Ordinary chocolate mass has lower taste and aroma qualities and less fine dispersion. The sugar content in it is no more than 63%. Porous chocolate is obtained mainly from dessert chocolate mass, which is poured into molds ¾ of the volume, placed in vacuum- boilers and kept in a liquid state (at a temperature of 40 ° C) for 4 hours. When the vacuum is removed, due to the expansion of air bubbles, a finely porous tile structure is formed (“The Little Humpbacked Horse,” “Glory,” “Planet,” “Congratulations,” Wispa, Schgetten, Sonnina). Depending on the composition, chocolate is divided into chocolate without additives, with additives, with filling, diabetic and white. Chocolate without additives made from cocoa mass, powdered sugar and cocoa butter. This chocolate has specific properties inherent in cocoa beans. By changing the ratio between powdered sugar and cocoa mass, you can change the taste characteristics of the resulting chocolate - from bitter to sweet. The more cocoa mass in chocolate, the more bitter the taste and the brighter the aroma of the chocolate and the more valued it is. Chocolate with additions made from cocoa mass, cocoa butter, powdered sugar and various nutritional, flavoring and aromatic substances. Dry ingredients are most often used as additives. milk, dry cream, kernels nuts, coffee, waffles, candied fruit, alcohol, cognac, vanillin, food essences and more. The ratio between the listed components of chocolate reflects the characteristics of its assortment and varies widely. Chocolate with filling prepared from chocolate mass without additives and with the addition of milk. It is produced in the form of bars, loaves, shells and other shapes with various fillings: nuts, fondant, chocolate, fruit jelly, cream, milk, butter. The amount of filling should be no more than 50% of the total weight of the products (Assortid, Coconut). Diabetic chocolate intended for patients diabetes mellitus. Instead of sugar, chocolate contains: sorbitol, xylitol, mannitol. Chocolate white prepared according to a special recipe from cocoa butter, sugar, milk powder, vanillin without adding cocoa mass, so it has a cream color (white) and does not contain theobromine(“Khreshchatyk”, “Children’s”, “Air” and others). Depending on the form, chocolate is produced in the form of bars, shapes and powder. Chocolate figures are made from dessert chocolate mass in the form of various hollow objects and animal figures. Powdered chocolate is made from cocoa mass and powdered sugar without any additives or with the addition of dairy products (Suflair, Karina, Schogetten).

The history of chocolate

Chocolate - history of invention

Chocolate is usually considered a treat for children. If we were to travel back approximately three thousand years, the popular belief would certainly be refuted. Chocolate has long been exclusively a drink. It was consumed cold - roasted cocoa beans, which themselves have a bitter taste, were mixed with water, and then chili pepper was added to this mixture. The ancient Omelki civilization, which was the first to try the invented drink, gave it the name that is still used today. They said "kakawa". It is surprising that over such a long time only a few letters have changed in the name. Contrary to the name, the composition of chocolate has undergone significant changes since then, but the road to this has been long. Around the same time, namely three thousand years ago, another delicacy was invented, which is now inextricably linked with chocolate. The ancient Egyptians accidentally mixed honey, figs and nuts - and became the owners of the world's first candies.

Cocoa beans instead of coins.

By 600 AD, chocolate had not lost a single component of its original composition. The history of the development of chocolate was continued by the Mayan tribe. During this period, paganism caused chocolate to become a very valuable drink; many religious rituals and traditions were associated with it. The value of chocolate was great, because it was considered the food of the gods. The Mayan Indians at that time lived in Central America, on the Yucatan Peninsula. Now this territory is located in Mexico, where chocolate is currently familiar, but therefore no less important. During the Mayan era, cocoa trees were deliberately not grown. There were a lot of them growing, but not enough for everyone to drink enough of the divine drink. As a result, the Indians began to use cocoa beans as a means of payment. Every fruit counted: for 100 cocoa beans, for example, you could buy a slave. When calculations were carried out in considerable amounts, the fruits were counted not individually, but in pods, each of which weighs about 500 g, and for the purpose of profit, the ancient “counterfeiters” took cocoa beans out of the pods and filled them with something less valuable. Later, the impracticality and value of cocoa fruits prompted the Mayan Indians to begin building cocoa plantations - as you know, there should be a lot of good things.

A gift from the Aztecs.

The Aztecs of Central America had a much simpler time regarding cocoa. The Indians who lived on their territory earlier erected plantations, and the harvest grew larger from year to year. The value of the tree's fruits decreased slightly, and cocoa beans began to be used as tribute. This was the period of the first long-distance voyages and discoveries, a step towards chocolate becoming known in Europe. So, in 1517, the Spaniard Hernan Cortez arrives in Mexico. The Aztecs take him for the returning god Quetzalcoatl. But Cortez's plans also turned out to be grandiose: he conquered Mexico. And he also realized that “chocolatl” would help him gain an excellent position in his homeland. Cortez was not mistaken. The ships that loaded cocoa beans and cocoa production devices became a real discovery for Spain. The Spaniards were in no hurry to distribute chocolate outside the country; supply volumes did not allow this. In addition, they kept the recipe for the drink secret. What the Spaniards did with cocoa beans is already closer to the chocolate that we know. The new recipe included cinnamon, nutmeg and sugar. Chili peppers began to be bypassed, and the drink was now served hot. These changes turned out to be good for chocolate.

Chocolate storage

Store chocolate at a temperature of 18 0 C and a relative humidity of 75%. Under these conditions, chocolate is stored for the following warranty periods from the date of production:

dessert and regular without additives – 6 months,

weight without additions unwrapped – 4 months,

dessert and regular with additions, chocolate with filling and in powder without additions – 3 months,

by weight with additions, unwrapped – 2 months,

white and powdered chocolate with added dairy products – 1 month.

To avoid browning of the chocolate, sudden temperature fluctuations are not allowed. When heated (temperature above 20 0 C), fat blooming of chocolate occurs - it becomes covered with a gray coating. It is the fats contained in chocolate that appear on its surface. At temperatures below 18 0 C, sugar bloom of chocolate occurs, caused by condensation of water vapor and partial dissolution of sucrose contained in chocolate. After the moisture evaporates, sucrose crystals form a white coating on the surface of the chocolate.

III. experimental part

Objects of study:

Dark chocolate "Russian"

Manufacturer: OJSC "Confectionery Association of Russia"

Compound: Sugar, cocoa mass, crushed almonds, cocoa butter, stabilizer (milk fat), alcohol, emulsifier, soy lecithin E476, salt, flavoring identical to natural (rum).

Milk chocolate "Alenka"

Manufacturer: JSC "Red October"

Compound: Sugar, whole milk powder, cocoa butter, cocoa mass, emulsifiers: lecithin E476, flavoring identical to natural “Vanilla”.

White chocolate “Porous”

Manufacturer: JSC "Russian Chocolate Factory"

Compound: Sugar, cocoa butter, whole milk powder, lactose, whey powder, emulsifiers: E322, E476, vanilla flavoring

Table No. 1



Name chocolate	Squirrels (in 100 g)	Fats (in 100 g)	Carbohydrates (in 100 g)	Energy Value (kcal)
"Russian"
Lactic "Alenka"
"Porous"

Experience No. 1. Determining the quality of a “chocolate bar”.

(According to GOST, the composition of a “chocolate bar” should include only crushed cocoa beans and cocoa bean butter. When vegetable fats and soy are added to these products, the final product should be called a “sweet bar.” “White chocolate” contains a small amount cocoa bean butter, the base of this chocolate is condensed milk.

To conduct the experiment, we take samples of chocolate bars of different brands weighing 5 g, place them in different test tubes and heat them in a water bath until melting ends. Using a thermometer, we determine the melting point of the sample. The measurement results are entered into the table (Table No. 2). As the proportion of vegetable fats in chocolate increases, and therefore the chemical composition of chocolate, the melting point of chocolate decreases

Table No. 2

Name of chocolate	Melting temperature 0 With
Dark chocolate "Russian"
Milk chocolate "Alenka"
White chocolate “Porous”

Conclusion:The lower the melting point, the more vegetable fats and less cocoa butter. “Alenka” chocolate has the best composition.

Experience No. 2. Determination of the presence of foreign impurities in chocolate.

Pour a small amount of hot water into a flat-bottomed flask, drop in a piece of chocolate sample weighing 5 g, and place the flask in a water bath. After waiting for the chocolate to completely dissolve and cool the contents of the flask, add a few drops of an alcohol solution of iodine to the contents of the flask. If the chocolate is mixed with mealy or starchy substances, the broth will turn bluish; A decoction of pure, unadulterated chocolate under the influence of the same reagent turns slightly greenish. We enter the data on all samples of chocolate products into the table (Table No. 3).

Table No. 3

Name of chocolate	Presence of impurities
Dark chocolate "Russian"
Milk chocolate "Alenka"
White chocolate “Porous”

Experience No. 3. Detection of unsaturated fats in chocolate (cocoa bean butter).

A piece of chocolate must be wrapped in filter paper and pressed on it so that grease stains appear on the filter paper. We place a drop of a 0.5 M solution of potassium permanganate KMnO 4 on the grease stain and a brown precipitate of manganese (IV) oxide - MnO 2 - is formed due to the redox reaction.

Conclusion: Unsaturated fats were found in “Alenka” and dark “Russian” chocolate

Experience No. 4. Detection of carbohydrates in chocolate

Pour grated chocolate into a test tube and add 2 ml of distilled water. Shake the contents of the test tube well several times and filter. To the filtrate add 1 ml of a 2M solution of sodium hydroxide NaOH and 2-3 drops of a 10% solution of copper (II) sulfate CuSO 4, shake the test tube vigorously. A bright blue color appears. This reaction is produced by sucrose, which is a polyhydric alcohol.

Conclusion: The most sucrose is in the white “Porous”, and the least in the dark “Russian”

Experience No. 5. Detection of proteins in chocolate (xanthoprotein reaction).

Pour grated chocolate into a test tube (about 1 cm in height) and add 2 ml of distilled water. Shake the contents of the test tube well several times and filter. Add 0.5 ml of concentrated nitric acid HNO3 to 1 ml of the resulting filtrate and heat the resulting mixture. We observe a yellow color, turning into orange-yellow when adding a 25% aqueous ammonia solution. This reaction is produced by the residues of aromatic amino acids that make up chocolate proteins.

Conclusion: All samples contain proteins. Most of all in dark chocolate "Russian"

I enter the data from experiments No. 3-5 into the table (Table No. 4).

Table No. 4

Experience	Dark chocolate	Milk chocolate	White aerated chocolate
detection of unsaturated fats	discovered	discovered	not detected
carbohydrate detection	present	present
protein detection		present	present

IV.Conclusion

The effect of chocolate on the body

The rich chemical composition of chocolate itself speaks volumes about the value of this product. This is where the benefits of chocolate lie.

Chocolate activates the production of endorphins, happiness hormones, improves tone and mood, performance and the ability to concentrate. The reason is theobromine, it stimulates the central nervous system, invigorates and relieves headaches. Serotonin, phenylethylamine and tryptophan are excellent antidepressants. Magnesium resists depression, stress, improves memory, has a beneficial effect on the immune system, and promotes the circulation of cellular metabolism.

Dark chocolate lowers blood pressure and promotes increased absorption of sugar.

The alkaloid caffeine is a psychostimulant and activates the activity of the cardiovascular, nervous and respiratory systems. It invigorates, increases mental and physical activity, relieves vascular headaches, and fights childhood enuresis.

Magnesium and potassium are essential for the central nervous system and muscles; phosphorus for brain activity, calcium for bones, fluoride for teeth.

Antioxidants (polyphenols, catechins, flavonoids) stop aging and normalize cardiac activity by fighting free radicals. All flavonoids help regulate processes in the skin, preserving its youth for a long time. Kokokhil has a wound-healing, wrinkle-smoothing, skin cell-renewing effect.

Sweet aspirin - chocolate - helps thin the blood. Reduces headaches and sore throat. Cocoa flavonoids improve metabolic functions and prevent the formation and deposition of cholesterol in blood vessels and their damage.

The antibacterial effect of chocolate theanins prevents the formation of plaque, thereby fighting caries.

Theobromine and theophylline activate skin biochemistry, providing lifting.

Chocolate caffeine is a leader in the fight against excess weight and cellulite, it normalizes lymph and blood flow, relieves swelling, activates the breakdown and elimination of negatively acting fats, toxins and waste.

However, chocolate also has its downsides.. The tannin contained in chocolate can cause headaches in people with poor blood vessels, and too much chocolate at night can cause untimely alertness and deprive sleep. Eating large amounts of chocolate not only can cause allergies, but also greatly increases your heart rate. Chocolate is a high-calorie product and consuming it in excess can cause weight gain.

Questionnaire

19 students of grades 7, 8, 9 took part in the survey.

Question 1. Do you like chocolate? (yes, no)

Answer: Yes-100%.

Question 2. What kind of chocolate do you like? (Dark, milky, white)

Answer: tastes are different - 5 students like dark chocolate, 9 like milk chocolate, 5 like white chocolate

Question 3. How often do you eat chocolate? (every day, once a week, once a month)

Answer: every day - 2 students; 1 time per week - 11 students: 1 time per month - 6 students

Question 4: Is chocolate healthy or harmful?

Answer: 14 students think chocolate is healthy; 5 students consider it harmful

Applications of chocolate

Currently, chocolate and its products are used in various fields of activity. Cocoa seed powder, as we know, is used to make cocoa drink and chocolate. Cocoa seed oil is also used in food production and is used in medicine to produce the base of suppositories (candles). The husks of cocoa beans (seeds) are used in the production of toothpaste. It contains an antibacterial substance that “fights” plaque on the teeth. Just a few years ago, such super-fashionable procedures as chocolate wraps, chocolate baths, chocolate masks appeared in Russia - and it seems that this is a panacea for old age. Using chocolate in cosmetic procedures in beauty salons and even at home on your own allows you to always remain young and beautiful.

With chocolate treatments you can:

get rid of cellulite

do a face, neck, décolleté lift

restore skin elasticity to any problematic part of the body

lose weight

experience the relaxing effects of a chocolate bath

moisturize your face

lift your mood (aromatherapy)

get rid of postpartum stretch marks and spider veins

get rid of “young” keloid scars.

Conclusions from the work

1. During the work, samples of chocolate that were in demand among the population were examined: Dark chocolate “Russian”, Milk chocolate “Alenka”, White chocolate “Porous”.

2. Real chocolate is a confectionery product in the production of which only cocoa butter and cocoa mass are used (a mixture of grains of cocoa beans in cocoa butter), and not a product based on cocoa powder and cocoa butter substitutes based on vegetable fats.

3. The studied chocolate product is not adulterated with by-products.

4. The highest content of unsaturated fats was observed in milk chocolate “Alenka” and dark “Russian”; the qualitative reaction to carbohydrates was most clearly manifested in white “Porous” chocolate.

5. The healthiest is Alenka milk chocolate without fillings or additives, containing a maximum of cocoa products.

6. Chocolate is not harmful to health if consumed in moderation!

V. Application

Recipes of modern cosmetology

Chocolate masks

A chocolate mask is a mixture of chocolate powder, which includes natural extracts of plants and fruits, seaweed, clay and other active ingredients, and warm water and cocoa bean butter; when mixed, it forms a plastic consistency. This mask is applied to previously cleansed body skin - with your hands, and on the face (avoiding the area around the eyes), neck, and décolleté with a brush. After 15-20 minutes, the mask is washed off with warm water and removed with wet wipes. The final stage is the use of cream and serum appropriate to your skin type and care program.

For dry skin . In this case, we need white chocolate and yogurt. Melt 2 tablespoons of chocolate in a water bath. Add 1 tablespoon of yogurt to liquid chocolate (without fruit additives with the highest fat content). Beat the resulting mixture with a mixer and apply it to your face for 15 minutes. The result is soft, moisturized and fragrant skin.

For normal and combination skin . A dark chocolate mask is suitable for us. Melt 2 tablespoons of dark chocolate in a water bath, then add 1 teaspoon of olive oil. After cooling the mixture to room temperature for 10 minutes, apply it to your face and then wash off with warm water. The mask nourishes and tightens the skin, giving it freshness and golden color.

Any of these masks will bring unearthly pleasure, lift your spirits and improve the condition of your skin.

Mask for dull and sparse hair . Mix 2 tablespoons of cocoa butter with a teaspoon of cognac. Apply the mask to the scalp and hair roots, massage lightly. Leave for 10-15 minutes, rinse with shampoo. This mask is done once or twice a week and stimulates blood circulation in the scalp, nourishes the hair, and helps supply it with the necessary vitamins and oxygen.

VI. Bibliography

Bogdanov A.K. - “Chocolate in the Russian tradition” Moscow “Essays” 1996

Vorobyov V.I. - Moscow “Components of health” “Knowledge” 1987

A book about tasty and healthy food. – Moscow “Food Industry” 1963

Pruzhnikov I. I. “Cup of Chocolate” - Moscow “Food Industry” 1997

5. Skurikhin I.M., Nechaev A.P. – Moscow “All about food from the point of view

chemist's point of view" "Higher School" 1991

6. Fremantle M. - Moscow “Chemistry in Action” “Enlightenment” 1990

7.Internet site: www.samcond.ru

Every day on store shelves we regularly see chocolate products from the brands “Alenka”, “Alpen Gold”, “Globus”, “Russia is a Generous Soul” and others. Milk chocolate is a popular dessert among Russians, but it's worth looking into whether this treat is safe for consumers.

Chocolate is a product that has been known since ancient times. Even the Indians who lived in Central America learned to make a drink called chocolatl from the fruits of cocoa trees growing in these parts - in addition to cocoa beans, various spices and spices, honey, agave juice, vanilla and other components were added to it, the composition of which could vary. The Indians discovered that the drink not only tastes great, but also lifts the mood, invigorates and increases potency. Thanks to these properties, cocoa beans became of great value and, according to some sources, were even used as money.

Spanish conquistadors brought cocoa beans to Europe in the 17th century, and it began its victorious march around the world. It was then that the drink chocolatl evolved into a more familiar solid delicacy.

For every taste

Belgium is one of the world leaders in the production of chocolate, and once in this country, you can try not only the usual varieties - milk, bitter, with nuts, confiture, dried fruits and candied fruits, but also more exotic variations. For example, the windows of Belgian chocolate shops display salted chocolate, chocolate with onions, garlic or hot spices, and the product itself is often used as one of the ingredients in sauces served with meat dishes. Belgian chocolate is considered to be of very high quality and is quite expensive, but despite the price, it is still in great demand, because they jokingly say about the inhabitants of this country that it will be easier for them to live without a government than without chocolate.

Chocolate without notes

Of course, you won’t find such variety as in Belgium on Russian shelves, but the selection of milk chocolate in our stores is quite wide. Chocolate is very popular, both adults and children love it. This is not surprising, because the treat helps lift your mood and cope with stress. Perhaps the only negative aspect of eating chocolate is the risk of gaining extra pounds.

Of course, you can enjoy your food if you bought high-quality chocolate, and not an obscure plasticine substance that they are trying to pass off as this product. In order to find out which chocolate will not disappoint consumers, the NashPotrebnadzor program, which airs on the NTV channel, together with the non-profit organization Roskachestvo, examined the products of well-known manufacturers. The experiment affected chocolate “Globus”, “Alpen Gold”, “Mishka in the North”, “Okay”, “Russia is a Generous Soul”, “Air”, “Sobranie”, “Alenka”, “Milka” and “Ritter Sport” "

The main component of any chocolate is cocoa. The study showed that all samples here met the GOST standards, however, “Ritter Sport” became the champion in cocoa content, and the second place was deservedly given to “Mishka in the North”, which was slightly behind it.

There is no milk chocolate without milk, but the manufacturers of Globus products obviously think otherwise. The milk content in their chocolate does not comply with GOST standards.

Experts also tested the chocolate for the content of heavy metals - cocoa beans can indeed contain substances hazardous to human health if they were grown near industrial enterprises, however, this does not apply to any of the brands presented in the study - all chocolate is completely safe.

Thus, based on the results of the analysis, only Globus chocolate received criticism from experts. All other products are of high quality, will not harm health and will not deceive the gastronomic expectations of the consumer.

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Introduction

Objective of the project : explore the chemical composition of different brands of chocolate and study its effects on human health.

Research objectives:

Get to know different types of chocolate.
Study the chemical composition of different types of chocolate.
Conduct a qualitative analysis of the studied samples of chocolate products.
Compare their chemical composition.
Study the effect of chocolate on human health.
Conduct a survey among classmates about the dangers and benefits of chocolate.
Find out how chocolate is currently used in medicine and cosmetology.

Object of study: chocolate.

Subject of study: chemical analysis of the composition of chocolate.

Project type : individual, long-term, interdisciplinary (chemistry and biology), experimental.

Forms for presenting project results: report, presentation.

Literature review

Chocolate - (English Chocolate, French Chocolat, Spanish Chocolate ) is a term denoting various types of confectionery products made using cocoa fruits. One of the most common confectionery products. It contains proteins, fats, carbohydrates, tannins, alkaloids caffeine and theobromine. It is prepared on the basis of cocoa products.

E thymology of the name:The word "chocolate" comes from "chocolatl", the name of a drink made from cocoa beans. In the Aztec language, "chocolli" means "bitterness" and "atl" refers to the water used to make the chocolate drink.

GOST No. 6534-69

According to state industry standard No. 6534-69, chocolate is:

taste and aroma clearly expressed, characteristic of this species
color from light brown to dark brown, for white chocolate – cream
form correct, without deformation, in the form of tiles, loaves, various shapes, both with and without a pattern
front surface chocolate should be shiny, without sugar and fat bloom, in chocolate with milk - slightly dull, in chocolate with uncrushed additives the bottom side of the bar has an uneven surface
consistency should be hard, the structure should be uniform, the fracture should be matte, for porous chocolate – cellular
additions, not introduced in finely ground form, are evenly distributed in the chocolate mass.

Chemical composition of chocolate and cocoa beans

The average composition of cocoa beans is given in table No. 1.

substances	composition in%
Fat	45-50 %
Nitrogenous substances	13-16 %
Cellulose	3-9 %
Starch	5-10 %
Tannins (tannin) and coloring matter	5-7 %
Theobromine	1-2,4 %
Pentosans	1-2 %
Essential oil	0,001 %
Organic acids (malic, citric, oxalic)	up to 2%
Water	6-9 %
Ash	2,5-5 %
Caffeine	40 %
Saccharides
Squirrels	11,5 %
Other minerals and salts	2,6 %

Chocolate classification

Depending on the processing method, chocolate mass is divided into dessert and ordinary.Dessert chocolate masshas high aromatic qualities and finedispersion. It acquires these properties as a result of particularly careful and lengthy processing. ContentSaharait contains no more than 55%.Ordinary chocolate masshas lower taste and aroma qualities and less fine dispersion. The sugar content in it is no more than 63%. Porous chocolate is obtained mainly from dessert chocolate mass, which is poured into molds ¾ of the volume, placed invacuum- boilers and kept in a liquid state (at a temperature of 40 ° C) for 4 hours. When the vacuum is removed, due to the expansion of air bubbles, a finely porous tile structure is formed (“The Little Humpbacked Horse,” “Glory,” “Planet,” “Congratulations,” Wispa, Schgetten, Sonnina). Depending on the composition, chocolate is divided into chocolate without additives, with additives, with filling, diabetic and white.Chocolate without additivesmade from cocoa mass, powdered sugar and cocoa butter. This chocolate has specific properties inherent in cocoa beans. By changing the ratio between powdered sugar and cocoa mass, you can change the taste characteristics of the resulting chocolate - from bitter to sweet. The more cocoa mass in chocolate, the more bitter the taste and the brighter the aroma of the chocolate and the more valued it is.Chocolate with additionsmade from cocoa mass, cocoa butter, powdered sugar and various nutritional, flavoring and aromatic substances. Dry ingredients are most often used as additives.milk, dry cream, kernels nuts, coffee, waffles, candied fruit, alcohol, cognac, vanillin, food essences and more. The ratio between the listed components of chocolate reflects the characteristics of its assortment and varies widely.Chocolate with fillingprepared from chocolate mass without additives and with the addition of milk. It is produced in the form of bars, loaves, shells and other shapes with various fillings: nuts, fondant, chocolate, fruit jelly, cream, milk, butter. The amount of filling should be no more than 50% of the total weight of the products (Assortid, Coconut).Diabetic chocolateintended for patientsdiabetes mellitus. Instead of sugar, chocolate contains:sorbitol, xylitol, mannitol.

Chocolate white prepared according to a special recipe from cocoa butter, sugar, milk powder, vanillin without adding cocoa mass, so it has a cream color (white) and does not containtheobromine(“Khreshchatyk”, “Children’s”, “Air” and others). Depending on the form, chocolate is produced in the form of bars, shapes and powder. Chocolate figures are made from dessert chocolate mass in the form of various hollow objects and animal figures. Powdered chocolate is made from cocoa mass and powdered sugar without any additives or with the addition of dairy products (Suflair, Karina, Schogetten).

The history of chocolate

Chocolate - history of invention

Chocolate used to be considered a delicacy for children. If we were to travel back approximately three thousand years, the popular belief would certainly be refuted. Chocolate For a long time it was exclusively a drink. It was consumed cold - roasted cocoa beans, which themselves have a bitter taste, were mixed with water, and then chili pepper was added to this mixture. The ancient Omelki civilization, which was the first to try the invented drink, gave it the name that is still used today. They said "kakawa". It is surprising that over such a long time only a few letters have changed in the name. Contrary to the name, the composition of chocolate has undergone significant changes since then, but the road to this has been long. Around the same time, namely three thousand years ago, another delicacy was invented, which is now inextricably linked with chocolate. The ancient Egyptians accidentally mixed honey, figs and nuts - and became the owners of the world's first candies.

Cocoa beans instead of coins.

A gift from the Aztecs.

Chocolate storage

Store chocolate at a temperature of 18 0 C and relative humidity 75%. Under these conditions, chocolate is stored for the following warranty periods from the date of production:

dessert and regular without additives – 6 months,
weight without additions unwrapped – 4 months,
dessert and regular with additions, chocolate with filling and in powder without additions – 3 months,
by weight with additions, unwrapped – 2 months,
white and powdered chocolate with added dairy products – 1 month.

To avoid browning of the chocolate, sudden temperature fluctuations are not allowed. When heated (temperature above 20 0 C) fat bloom of chocolate occurs - it becomes covered with a gray coating. It is the fats contained in chocolate that appear on its surface. At temperatures below 18 0 Sugar bloom of chocolate occurs, caused by condensation of water vapor and partial dissolution of sucrose contained in chocolate. After the moisture evaporates, sucrose crystals form a white coating on the surface of the chocolate.

experimental part

Objects of study:

Dark chocolate "Russian"

Manufacturer : OJSC "Confectionery Association of Russia"

Compound : Sugar, cocoa mass, crushed almonds, cocoa butter, stabilizer (milk fat), alcohol, emulsifier, soy lecithin E476, salt, flavoring identical to natural (rum).

Milk chocolate "Alenka"

Manufacturer : JSC "Red October"

Compound : Sugar, whole milk powder, cocoa butter, cocoa mass, emulsifiers: lecithin E476, flavoring identical to natural “Vanilla”.

White chocolate “Porous”

Manufacturer : JSC "Russian Chocolate Factory"

Compound : Sugar, cocoa butter, whole milk powder, lactose, whey powder, emulsifiers: E322, E476, vanilla flavoring

Table No. 1


name of chocolate	squirrels	fats	carbohydrates	the nutritional value
Dark "Russian"	6.6 g	32.6 g	52.1 g	529 kcal
Lactic "Alenka"	8.2 g	33.3 g	53.5 g	538 kcal
White "Porous"	6.5 g	33.4 g	56.5 g	547 kcal

Experience No. 1. Determining the quality of a “chocolate bar”.

To conduct the experiment, samples of chocolate bars of different brands weighing 5 g are taken, placed in different test tubes and heated in a water bath until melting is completed. A thermometer is used to determine the melting point of the sample. The measurement results are entered into the table (Table No. 2). As the proportion of vegetable fats in chocolate increases, and therefore the chemical composition of chocolate, the melting point of chocolate decreases

Table No. 2

Conclusion: The lower the melting point, the more vegetable fat and less cocoa butter. “Alenka” chocolate has the best composition.

Experience No. 2. Determination of the presence of foreign impurities in chocolate.

Table No. 3

Experience No. 3. Detection of unsaturated fats in chocolate(cocoa bean butter).

A piece of chocolate must be wrapped in filter paper and pressed on it so that grease stains appear on the filter paper. A drop of 0.5 M solution of potassium permanganate KMnO is placed on the grease stain. 4 and a brown precipitate of manganese (IV) oxide - MnO is formed due to the occurrence of the redox reaction 2 .

Conclusion: Unsaturated fats were found in “Alenka” and dark “Russian” chocolate

Conclusion: Three bright colored rings are expressed in white chocolate. Carbohydrates are present everywhere.

Experience No. 6. Detection of proteins in chocolate (xanthoprotein reaction).

Pour grated chocolate into a test tube (about 1 cm in height) and add 2 ml of distilled water. Shake the contents of the tube well several times and filter. To 1 ml of the resulting filtrate add 0.5 ml of concentrated nitric acid HNO 3 and heat the resulting mixture. A yellow color is observed, turning into orange-yellow upon addition of a 25% aqueous ammonia solution. This reaction is produced by the residues of aromatic amino acids that make up chocolate proteins.

Conclusion : All samples contain proteins. Most of all in dark chocolate "Russian"

I enter the data from experiments No. 3-6 into the table (Table No. 4).

Table No. 4

Experience	Dark chocolate	Milk chocolate	White aerated chocolate
detection of unsaturated fats	Discovered	discovered	not detected
carbohydrate detection	present	present	3 rings are clearly visible
protein detection	More protein content	present	present

The effect of chocolate on the body

The rich chemical composition of chocolate itself speaks volumes about the value of this product. This is where the benefits of chocolate lie.

Chocolate activates the production of endorphins, happiness hormones, improves tone and mood, performance and the ability to concentrate. The reason is theobromine, it stimulates the central nervous system, invigorates and relieves headaches. Serotonin, phenylethylamine and tryptophan are excellent antidepressants. Magnesium resists depression, stress, improves memory, has a beneficial effect on the immune system, and promotes the circulation of cellular metabolism.
Dark chocolate lowers blood pressure and promotes increased absorption of sugar.
The alkaloid caffeine is a psychostimulant and activates the activity of the cardiovascular, nervous and respiratory systems. It invigorates, increases mental and physical activity, relieves vascular headaches, and fights childhood enuresis.
Magnesium and potassium are essential for the central nervous system and muscles; phosphorus for brain activity, calcium for bones, fluoride for teeth.
Antioxidants (polyphenols, catechins, flavonoids) stop aging and normalize cardiac activity by fighting free radicals. All flavonoids help regulate processes in the skin, preserving its youth for a long time. Kokokhil has a wound-healing, wrinkle-smoothing, skin cell-renewing effect.
Sweet aspirin - chocolate - helps thin the blood. Reduces headaches and sore throat. Cocoa flavonoids improve metabolic functions and prevent the formation and deposition of cholesterol in blood vessels and their damage.
The antibacterial effect of chocolate theanins prevents the formation of plaque, thereby fighting caries.
Theobromine and theophylline activate skin biochemistry, providing lifting.
Chocolate caffeine is a leader in the fight against excess weight and cellulite, it normalizes lymph and blood flow, relieves swelling, activates the breakdown and elimination of negatively acting fats, toxins and waste.

However, chocolate also has its downsides. The tannin contained in chocolate can cause headaches in people with poor blood vessels, and too much chocolate at night can cause untimely alertness and deprive sleep. Eating large amounts of chocolate not only can cause allergies, but also greatly increases your heart rate. Chocolate is a high-calorie product and consuming it in excess can cause weight gain.

Sociological survey

21 10th grade students took part in the survey.

Applications of chocolate

With chocolate treatments you can:

get rid of cellulite
do a face, neck, décolleté lift
restore skin elasticity to any problematic part of the body
lose weight
experience the relaxing effects of a chocolate bath
moisturize your face
lift your mood (aromatherapy)
get rid of postpartum stretch marks and spider veins
get rid of “young” keloid scars.

Conclusions from the work

During the work, samples of chocolate that were in demand among the population were examined:Dark chocolate “Russian”, Milk chocolate “Alenka”, White chocolate “Porous”.Real chocolate is a confectionery product in the production of which only cocoa butter and cocoa mass are used (a mixture of grains of cocoa beans in cocoa butter), and not a product based on cocoa powder and cocoa butter substitutes based on vegetable fats.The chocolate product studied (not adulterated or adulterated) with by-products. The highest content of unsaturated fats was observed in milk chocolate “Alenka” and dark “Russian”; the qualitative reaction to carbohydrates was most clearly manifested in white “Porous” chocolate.

The healthiest is Alenka milk chocolate without fillings or additives, containing a maximum of cocoa products. Chocolate is not harmful to health if consumed in moderation!

Application

Recipes of modern cosmetology

Chocolate masks

For dry skin . In this case, we need white chocolate and yogurt. Melt 2 tablespoons of chocolate in a water bath. Add 1 tablespoon of yogurt to liquid chocolate (without fruit additives with the highest fat content). Beat the resulting mixture with a mixer and apply it to your face for 15 minutes. The result is soft, moisturized and fragrant skin.

For normal and combination skin. A dark chocolate mask is suitable for us. Melt 2 tablespoons of dark chocolate in a water bath, then add 1 teaspoon of olive oil. After cooling the mixture to room temperature for 10 minutes, apply it to your face and then wash off with warm water. The mask nourishes and tightens the skin, giving it freshness and golden color.

Any of these masks will bring unearthly pleasure, lift your spirits and improve the condition of your skin.

Mask for dull and sparse hair. Mix 2 tablespoons of cocoa butter with a teaspoon of cognac. Apply the mask to the scalp and hair roots, massage lightly. Leave for 10-15 minutes, rinse with shampoo. This mask is done once or twice a week and stimulates blood circulation in the scalp, nourishes the hair, and helps supply it with the necessary vitamins and oxygen.

Bibliography

A book about tasty and healthy food. – Moscow “Food Industry” 1963
Pruzhnikov I. I. “Cup of Chocolate” - Moscow “Food Industry” 1997
Bogdanov A.K. - “Chocolate in the Russian tradition” Moscow “Essays” 1996
Vorobyov V.I. - Moscow “Components of health” “Knowledge” 1987
Skurikhin I.M., Nechaev A.P. - Moscow “Everything about food from the point of view of a chemist” “Higher School” 1991
Fremantle M. – Moscow “Chemistry in Action” “Enlightenment” 1990
Internet site: www.samcond.ru

For oily skin . A dark chocolate mask is suitable for us. Mix 1 tablespoon of melted dark chocolate with 1 tablespoon of fruit and berry puree. For the puree we need an apple, red currant (you can use cherries and cranberries). Season all this with 1 teaspoon of lemon juice. Apply the finished mask to your face for 10 minutes and wash off with warm water.

Experience No. 4.

Pour grated chocolate into a test tube and add 2 ml of distilled water. Shake the contents of the tube well several times and filter. To the filtrate add 1 ml of a 2M solution of sodium hydroxide NaOH and 2-3 drops of a 10% solution of copper (II) sulfate CuSO 4 , the test tube is shaken vigorously. A bright blue color appears. This reaction is produced by sucrose, which is a polyhydric alcohol.

Conclusion: The most sucrose is in the white “Porous”, and the least in the dark “Russian”

Experience No. 5

Detection of carbohydrates in chocolate

(Molisch color reaction).

Pour grated chocolate into a test tube (about 1 cm in height) and add 2 ml of distilled water. Shake the contents of the tube well several times and filter. Add 1-3 drops of an alcohol solution of resorcinol or thymol to the filtrate. We tilt the test tube and carefully pour 1-2 ml of concentrated sulfuric acid H along the wall 2 SO 4 . We fix the test tube in a vertical position. The heavy acid will sink to the bottom, and at its border with water a bright, beautiful ring will appear - red, pink or purple.