In the composition of gastric juice, hydrochloric acid occupies a significant place. She is its main component. Acid helps to ensure that food is processed properly and ensures its gradual movement from the stomach through the so-called pyloric sphincter (pyloric sphincter) into the duodenum.

It also performs other functions that are no less important for the human body:

• Promotes the processing and denaturation of protein in the gastric cavity. Thanks to this, its subsequent splitting is greatly facilitated.
• Promotes the activation of pepsinogens, which are converted into pepsins.
• Forms an acidic environment, without which the action of enzymes contained in gastric juice is impossible.
• Causes the process of pancreatic secretion.
• Promotes antibacterial action of gastric juice.

It is almost impossible for a modern person to protect himself from nervous tension, to do without stress, insignificant or bringing huge problems to life. The accelerated course of life, its rapid rhythm often do not leave time for observing the principles of proper and regular nutrition. Such overloads are reflected in the level of acidity of gastric juice, changing it in one direction or another. Then, without changing anything in the lifestyle, it is almost impossible to protect yourself from gastrointestinal diseases. Decreased or increased acidity of the stomach signals that a chronic disease, gastritis, may have appeared.

Determination of acidity

You can diagnose and determine the specific level of acidity in a medical facility. Modern research methods give fairly accurate results. But it is possible to establish whether the acidity is lowered or increased at home.

How to preliminary determine what is its tendency (increase or decrease) without leaving home? To do this, there is no need to spend money on expensive reagents, swallow the probe and take tests. At first, it is enough to take a closer look at your own body, to pay attention to the symptoms that were not there before. Indeed, if the acidity fluctuates upward or downward, this cannot but affect the state of health: it also changes.

Acidity increased: we determine independently

An increase in acidity is a pathology that negatively affects the general condition of the body. Since the walls of the digestive tract are irritated by an excess of acid, then such visible symptoms:

• Burning sensation in the region of the pharynx and esophagus, which occurs very sharply - heartburn... The reason for its appearance is the release of an excess amount of hydrochloric acid into the esophagus. Heartburn can occur at any time, for no apparent reason. But most often it is provoked by sour juices and foods containing a lot of spices and herbs. For example, these are tomato, plum, peach juices, smoked meats, mustard, ketchup. With increased acidity, heartburn will surely appear after eating lemons, grapefruits, kiwi, green apples.

  Alkaline mineral water, sunflower seeds, baking soda solution help quickly get rid of these unpleasant sensations.

• Copper and sour taste in the mouth... It occurs when you smell and smell sour foods. Even the very thought of lemons, sauerkraut or pickled cucumbers, sauerkraut, apples causes a significant amount of saliva in the mouth.
• Belching can occur regardless of the type of food. But as usual, like heartburn, it is observed when fried, fatty and spicy foods predominate in the diet. Sweet juices, jams, ice cream, cakes and biscuits also cause this unpleasant phenomenon.
• Aching, dull and pulling pain in the stomach... It intensifies when hunger appears. Often arises in the morning. These are the so-called "hunger pains". They almost always subside when a fresh portion of food enters the stomach.
• Heaviness in the abdomen and bloating after every snack, no matter how small.
• Violation of the defecation process: constipation or diarrhea... Both symptoms can cause reluctance to eat. After all, sometimes you just have to eat - your stomach instantly grabs, and further frequent trips to the toilet are provided.
• Taking anti-inflammatory drugs causes nausea or stomach pain. These symptoms appear immediately after taking medications.

In addition to the problems listed above, the manifestation of such signs of high acidity is also possible:

• Headaches after eating fatty, fried or smoked foods.
• Decreased or complete loss of appetite.
• The mood decreases, there is a breakdown and apathy.
• Stomach discomfort cannot but cause irritability.
• Attacks of nausea and vomiting. They come almost at the same hour when the consumption of food is over, or after a short period of time. But this symptom manifests itself much less often than all the previous ones.
• Stomach and digestive problems cover the tongue with a whitish-gray and yellow coating.

If none of the symptoms described are present, then the acidity of the stomach is within normal limits. But the feeling of at least a few of them should be the reason for contacting a gastroenterologist.

How to determine on your own whether the acidity is lowered

If the acidity is lowered, there is a desire to eat something sour: cabbage, cucumber, even lemon. Appetizing black rye bread, spices and seasonings, ketchup, apple and grapefruit juices.

A decrease in the content of hydrochloric acid is also a deviation from the norm, as is an increase. Solyanka, which is contained in gastric juice, neutralizes food products entering the esophagus from pathogenic microorganisms, harmful bacteria. When the acidity decreases, that is, the specific gravity of hydrochloric acid in the juice falls, the disinfection process fails. As a result, various unwanted bacteria enter the stomach, the number of which is growing.

The process of inflammation of the mucous membrane occurs, and the person develops symptoms, the most characteristic of which are:

• Eructation with a rotten egg smell or with a rotten taste. It provokes the appearance of bad breath, which is very unpleasant and has a putrid odor.
• Present feeling of bloated stomach, rumbling. Fermentation processes take place in the digestive tract. They cause pain from accumulated gas, flatulence.
• Burning sensation in the throat (heartburn).
• Feeling of heaviness in the hypochondrium.
• Dumb pain in the navel after every snack or a short time after it.
• Feeling as if something bursting from the inside.
• Stool disorders are another symptom of low acidity. An insufficient amount of acid in the gastric juice significantly reduces its antibacterial effect. Microorganisms that enter the human intestine unhindered, change its microflora, upset the balance. The person either suffers from constipation or cannot get rid of the diarrhea. Difficulty defecation is caused by intestinal motor disorders, which, in turn, are due to insufficient acidity.

A lowered level of it leads to incomplete assimilation of proteins. As a result, decay products accumulate in the stomach, which poison the entire body. Immunity decreases, and the door opens for the development of pathological processes. First of all, the appearance of various mycoses is possible: fungal lesions cover the mucous membranes of the oral cavity, skin, nails. The body becomes more susceptible to viruses and various infections.

Insufficient absorption of vitamins and minerals that are contained in food occurs. And, as a consequence, it is easy to see that:

• The skin on the hands and face becomes dry.
• Nails grow slowly, break and exfoliate.
• Hair becomes thinner and becomes brittle and dry. Their growth is also slowing down.
• The appearance of acne and vasodilation on the nose and cheeks are other visible signs of a decrease in acidity.

If the acidity has been lowered for a long time, then the person feels:

• General weakness.
• Weight loss.
• Lethargy and loss of strength.
• Inclination to a sedentary lifestyle and hypotension.

If you suspect the presence of low acidity, you need to carefully consider your feces. If they contain undigested food debris, its pieces - suspicions are justified.

Symptoms of low or high acidity do not appear all together. Typically only one or two signs are present.

In case of the appearance of such features and a slight disturbance of well-being, you can, of course, try to adjust the acidity of the stomach yourself. To do this, first of all, you need to adjust your diet.

But if the situation does not improve, and the discomfort increases, it is worth seeking help from a doctor. Special examination methods will help to accurately determine the acidity of the stomach and the causes of possible deviations. The sooner you undergo diagnosis and treatment, the fewer health problems will arise in the future.

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MOU "Secondary School No. 28"

Determination of acidity and sugar content of apple juice

Performed

Malysheva Olga

Vologda 2011

Introduction

3. Practical part

Conclusion

Bibliography

application

apple juice acidity sugar content

Introduction

Relevance and novelty

Juice is a healthy drink, the consumption of juice in winter is relevant, as it helps to meet the body's needs for vitamins and other useful substances. Therefore, the quality of the consumed juice is important for us. The survey showed that the most consumed juice is apple juice.

Study the composition of the juice and its effect on the body.

1. To study the consumption and popularity of juices among students of school № 28

2. Determination of acidity and sugar content of apple juice

3. Determination of dry matter

General scientific methods:

1. General theoretical:

- Analysis;

- Comparison.

2. Sociological:

- Questioning.

Specific scientific methods:

Theoretical:

- Analysis of literature;

Empirical:

- Observation;

- Experienced work.

1. Characteristics of juice drinks

There are the following main groups of juice drinks:

1. Fruit or vegetable juice - juice obtained from good-quality ripe, fresh fruits and vegetables, intended for direct consumption in food or for industrial processing. Juices are directly squeezed and reconstituted.

2. Fruit nectar is a liquid product obtained by mixing fruit juice or concentrated fruit juice with drinking water and sugar, in which the total mass fraction of fruit juice, depending on the type of fruit, is at least 25%

3. Fruit drink - a liquid product obtained from fresh or frozen berries, followed by mixing it with an extraction product with hot drinking water with or without added flavorings, with a mass fraction of berry juice or puree of at least 15%

4. Diffusion juice - a liquid product obtained by extracting extractive substances from pre-chopped fresh fruits or dry fruits of the same type with drinking water, the juice of which cannot be obtained mechanically

5. Concentrated natural volatile aroma-generating fruit (vegetable) substances - a liquid product obtained by physical methods from fruits, vegetables or their juices, including a natural complex of natural volatile aroma-forming substances, the content of which exceeds at least 4 times their natural content in fruits, vegetables or their juices. Concentrated aroma-forming fruit substances are used to restore aroma in juices made from concentrated juices, as well as in the manufacture of nectars and juice drinks.

2. The composition of the juice and its effect on the body

Apple juice is rich in healthy, easily digestible carbohydrates, sugars and organic acids; contains proteins, fats and dietary fiber, starch and even alcohol - a very small percentage. Apples are very rich in various vitamins (Appendix 1). There are more minerals in apples and apple juice than in many other fruits and juices: macronutrients - calcium, magnesium, sodium, potassium, phosphorus, chlorine, sulfur; trace elements - iron, zinc, iodine, copper, manganese, chromium, fluorine, molybdenum, boron, vanadium, aluminum, cobalt, rubidium, nickel.

Such a rich combination of nutrients has a positive effect on the body for many diseases: apple juice is useful for diseases of the liver, stomach, intestines, kidneys, bladder, etc.

But the effect on brain cells is completely different. Apple juice protects them from destruction, and even prevents the development of a very serious disease - Alzheimer's disease. Experiments in mice have shown that apple juice protects brain cells from oxidative stress during stress, which suggests its powerful antioxidant properties. It is enough to drink 300 g of apple juice per day to avoid the development of sclerosis of the cerebral vessels.

Thanks to natural sugars and organic acids, apple juice helps us recover after heavy exertion, strengthens the heart and blood vessels.

Regular consumption of apple juice normalizes blood cholesterol levels, supports heart function, and protects against radiation.

Contraindications for taking apple juice

There are few contraindications, but they are. You can not drink sweet and sour apple juice for gastritis with high acidity and serious diseases of the gastrointestinal tract, with allergies to red fruits, as well as with individual intolerance. Due to its high sugar content, it should not be consumed by diabetics or obese people. Heavy juice consumption can lead to chronic diarrhea.

3. Practical part

Questionnaire

To study a product, I decided to conduct a survey of school students and identify the most popular product. The questionnaire consisted of four questions:

1. What drink do you drink more often?

The most common answer was the answer "tea / coffee", with a small margin in second place is juice (Appendix 2). The popularity of tea is not surprising, as it warms in winter and quenches thirst in summer. But I preferred juice. For a more detailed result, a second question was asked.

2. What kind of juice do you prefer?

Less consumed juice is tomato juice. Orange juice is consumed much more, but apple juice is on the edge (Appendix 3).

3. Do you like juice with pulp?

More than eighty percent responded negatively, so I used pulp-free juices as the basis of the study.

4. What is the approximate amount of juice you drink per week?

The options 0-2 liters and 2-5 liters were divided approximately equally. The option "more than 5" received an insignificant number of votes

It was also suggested to write your favorite juice brand.

Based on this, I took the most popular answers for analysis, namely:

2. my family

3.Favorite

4 orchard

Determination of acidity

When determining the acidity of the juice, the total acidity is calculated in terms of the acid prevailing in the given juice.

The acidity of the juice is determined by adding an alkali solution of a certain concentration (titration solution) to it. Titre is the amount of alkali in 1 ml of solution, and titration is the determination of acidity using a titration solution. The result of the reaction when alkali is added to the juice is looked at by an indicator - litmus test. When determining the amount of acid, a titration solution of sodium hydroxide is used.

Titration solution. It is a solution of dry sodium hydroxide in the amount of 5.97 g., Dissolved in 1 liter of distilled water.

Determination of acid content

The essence of the method consists in adding a titration solution to a certain volume of juice until the litmus paper turns blue from the resulting mixture, which will mean the neutralization of all acid in the juice with alkali. Knowing the initial volume of juice and the volume of the used alkali titration solution, and that 1 ml of alkali neutralizes 0.1% acid, it is easy to determine the acidity of the juice.

Let's take a closer look at the following example. Let's say you have apple juice available. Place a clean, dry burette vertically on the table, then carefully pour 10 ml of juice into it. This is a strictly measured amount of juice by pouring it into a glass beaker. Then, in a glass with juice from a pipette, add the titration solution in measured portions, after each addition, mix the juice with a glass rod, and apply the drops from the glass rod to litmus paper. The red color of the litmus means that not all of the acid has yet been neutralized and therefore we add a new portion of the alkali titration solution. We will do this until the red color of the entire litmus paper changes to blue, which will be when all the acid is neutralized with alkali. Suppose we used 21 ml of an alkaline titration solution to neutralize 10 ml of apple juice, then this means that 1 liter of juice contains 21 g. malic acid, or 2.1% acid.

The results of this experiment are listed in the table (Appendix).

Determination of sugar content

The total amount of sugar in the juice can be determined by the specific gravity of the juice, which is based on the dependence of the density of the juice on the sugar content in it. Specific gravity is determined by weighing the measured amount of juice on an accurate balance or using a hydrometer. Before determining the amount of sugar, the juice must be filtered through a paper filter. The temperature of the juice should be 19-20 ° C.

If the temperature of the juice differs from 20 ° C, then the temperature correction is made to the hydrometer reading. If the temperature is above 20 ° C, then the value obtained from multiplying the difference in temperature degrees by 0.0002 must be added to the hydrometer reading. For example, at 25 ° C, the hydrometer reading is 1.053, and the actual weight will be: 1.053 + (5 x 0.0002) = 1.054. Conversely, at a juice temperature below 20 ° C, the temperature difference multiplied by 0.0002 must be subtracted from the hydrometer reading.

After making a temperature correction, the sugar content is determined by the specific gravity of the juice.

In addition to sugars, juice also contains extractives, the content of which is different in different juices. These extractives affect the accuracy of the results for determining the sugar content of the juice, allowing a deviation within 1. Therefore, when studying there are few extractive juices (for example, apple juice), 1 must be added to the sugar content by specific gravity. When calculating, use the formula:

C = (Y: 5) + 1,

We carried out the experiments at a set temperature of 20 ° C, therefore, no correction was made. The data of this experiment are entered in the table (Appendix 4).

Determination of dry matter

The dry substances in the juice are determined gravimetrically (by weighing). The dry residue consists of the actual dry matter of the original juice plus factory additives. The dry residue is calculated by the formula:

Dry residue,% = (M start - M end) / M start x 100,

M start - the mass of the flask with a sample before drying,

M con - the mass of the flask with a sample after drying

To determine the dry residue, we weighed 10 ml of juice, entered the data in the table (Appendix 5). Then the bowl with the juice was heated with an alcohol lamp until the moisture completely evaporated, avoiding charring. We again weighed the bowl, made the calculation using the formula described above. The obtained data were entered in the table (Appendix 5).

Conclusion on working with experiments

1. The highest acid content in the juice "I".

2. The lowest sugar content in the "Orchard" juice, but "I" juice is in second place. Thus, it can be considered a juice containing less sugar.

3. The highest proportion of dry residue in the juice "I", which indicates its usefulness

Investigating these qualities, we can say that "I" juice meets all the requirements and is the highest quality among those presented, as evidenced by its price. This juice is the most expensive (18.9 rubles).

In the juice "My family" the presence of acids is average, the sugar content is almost the highest, and the amount of dry residue is the lowest. Its price is the lowest (9.9 rubles).

Thus, we have drawn a line of value for money.

Conclusion

1. Apple juice is the most consumed (among juices) by school students

2. The chemical composition of the juice is complex and varied

3. The quality of the juice depends on the dry matter content, acidity and sugar content.

4. The best juice is the one with higher acidity, less sugar content and more dry residue.

5. Apple juice is very useful, protects many functions of the body

6. Has several contraindications in admission

Bibliography

1. Research of juice (publication on the Internet, http://vinum.narod.ru)

2. Composition of apple juice (publication on the Internet, http://www.ja-zdorov.ru)

3. The benefits and harms of apple juice (publication on the Internet, http://www.inflora.ru)

application

Demina Diana

The analysis of apple juices for organoleptic characteristics and total acidity was carried out

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District scientific and practical conference

"Youth to Science and Technology"

Determination of acidity and organoleptic characteristics of apple juice from various manufacturers

Izhevsk 2017

1. Introduction
2. Theoretical part

1. Juice history
2. Juice classification
3. Juice composition

1. Practical part

1. Experiment Technique
2. Results and its discussion

IV. conclusions

V. List of used literature

VI Appendix

I. Introduction

Anyone entering a store will surely see a shelf, or even a rack, where packages with juices and nectars are dazzling, their eyes run up from such an abundance! Probably everyone has their own favorite taste, favorite brand. We noticed that very often pupils buy juice in the cafeteria. I wonder why? Some even specifically defend a whole line just for the sake of the coveted box. Is it just to quench your thirst? Most likely not, in case there is water.

We wondered if the juice consumed by the students of our lyceum corresponded to the GOST data. These can be: acidity, organoleptic properties of the juices used. My classmates supported me in my research activities and willingly answered questions.

Purpose: Determine the organoleptic properties, acidity of the leading juices according to the survey results.

To achieve this goal, the following tasks :

* Conduct a survey about favorite juices of students of lyceum №25;

* Conduct an organoleptic analysis of the leading juices;

* Master the titration technique;

* Carry out a titration to determine the acidity of the leading juices;

* Summarize the results of the experiments.

Subject of study:apple juice from various manufacturers;

Object of study:acidity of the juice;

Research methods:theoretical (analysis of educational, popular science literature, Internet resources), experimental (titration method, chemical experience in determining organoleptic properties), static (processing of the data obtained);

1. Theoretical part

1. Juice history

The first written information about juices from various fruits and berries belongs to ancient Greek writers. It is known that the Greeks and Romans used the fruits of fruit trees not only for food, but also stored them in the form of juices as a medicine for certain diseases. Especially popular among the Greco-Romans were raspberry juices, rich in mineral salts (iron, potassium, copper), pectin (up to 0.9%) and fiber (4-6%), vitamins C (25 mg%), B, B2 , PP, folic acid, carotene. Juices were also known in Ancient China and Ancient Rus. For example, our ancestors especially appreciated the fruits of sea buckthorn, which grew wild in the valleys and floodplains of rivers in the south of the European part of Russia, in Western and Eastern Siberia, in the Caucasus and in Central Asia. Due to the high nutritional, especially taste, qualities of sea buckthorn, in Siberia, the berry was called "Siberian pineapple". Sea buckthorn juice was considered an indispensable tool in the prevention and treatment of hypovitaminosis. For long-term storage, the juice obtained from fresh berries and fruits was subjected to heat treatment by our ancestors, subsequently adding honey to the resulting drink.

In ancient times, the collected berries and fruits were ground with sugar, thereby extending the life of substances beneficial to the body by several months. Fruit and berry juices were also less popular in Soviet times. The Soviet Union produced about 550 million liters of juices per year. Basically, the juice assortment was represented by apple and tomato nectars and juices poured into 1 and 3 liter glass jars using pasteurization technology (hot filling).

In 1992, the expansion of the Russian market began from the side of imported juice products in "fashionable" cardboard aseptic packaging, and the development of a new Russian juice industry. The 90s were also marked by the appearance on the festive tables of Russians of juices from "overseas" fruits, such as oranges and pineapples. In the 2000s, the juice market in modern Russia experienced rapid growth. After the 1998 crisis, many foreign firms left the Russian market, thus making room for the development of national industries.

2.1. Juice classification

There are several definitions of what juice is:

1. Juice is a liquid food product obtained from the extraction of ripe edible fruits of vegetable or fruit crops.

2. Sap is the intercellular fluid of plants.

3. Juice is a liquid or suspension naturally found in fruits, berries and vegetables.

What juices are there?

Unclarified juice- juice with suspensions.

Clarified juice - juice from which suspended solids have been removed to a visual transparent state.

Juice with pulp - juice with pulp particles, the mass fraction of which does not exceed 55%.

Fruit juice - juice obtained from good-quality ripe, fresh and kept fresh due to cooling of fruits, unfermented, but fermentable, intended for direct consumption or industrial processing.

Directly squeezed fruit juice- fruit juice obtained directly from fruit by pressing, or centrifugation, or wiping.

Reconstituted fruit juice- fruit juice obtained by reconstitution of concentrated fruit juice with drinking water in a ratio that ensures the preservation of the physicochemical, microbiological, nutritional and organoleptic properties of juice from the fruits of the same name, with the simultaneous restoration of aroma by adding concentrated natural volatile aromatic substances or without aroma recovery, as well as with or without the addition of directly squeezed fruit juice of the same name, fruit puree.

Vegetable juice - juice obtained from the edible part of good-quality vegetables, unfermented or lactic fermented, intended for direct consumption or for industrial processing.

Certain types of juices are determined based on

1. The raw materials used (apple juice, carrot juice, etc.)
2. Manufacturing technologies (clarified, unclarified, with pulp)

3. The presence of additives (with sugar, without sugar)

2.3. Juice composition

Juice is a delicious and valuable nutritious product. The composition of fruit juices includes: water, natural carbohydrates (glucose, fructose, sucrose), organic acids (citric, malic, tartaric), protein, amino acids, vitamins (A, C, B1, B6, B9), minerals (K-potassium , Mg-magnesium, Ca-calcium), antioxidants, dietary fiber. The full composition of juices is presented in table 1.

Table 1

Nutritional value of juices (per 100 g)

The nutritional value of juices has led to their widespread use for the prevention and treatment of diseases. For example, orange juice kills bacteria, improves immunity, protects against some forms of cancer, grape juice normalizes metabolism, is effective for anemia, gastritis, neuroses. Pumpkin seed increases the level of hemoglobin in the blood, improves sleep, and helps to eliminate toxins from the body.

Natural flavors can be added to juices, as well as sugar, citric and ascorbic acids to adjust the taste. All added substances must be indicated in the composition of the product, which is indicated on the product packaging.

III. Practical part

3.1 Method of work execution

Purpose of the work: To determine the organoleptic properties, acidity of the leading juices according to the survey results.

3.1.1 Sociological survey

To select the objects of research, as well as to disclose some questions, a sociological survey was conducted among students of the lyceum (the questionnaire is presented in the appendix). According to the results of the sociological survey, we selected 6 samples for research (appendix)

3.1.2. Organoleptic quality assessment

In terms of organoleptic characteristics, the juice must meet the requirements of GOST 6687-89. Before testing the taste of juices, we rinsed our mouth with clean water each time. The study interval for the smell and taste of each type of juice was 3 minutes. As a result, we obtained the results presented below in the work

With sensory control, the taste, aroma and appearance of the drink are evaluated according to table 2,3,4.

table 2

Table 3

Table 4

1. Determination of titratable acidity

3.1.3.1 Preparation of sodium hydroxide solution

To determine the acidity of apple juices, we need a sodium hydroxide solution of exact concentration according to the method.To do this, we weighed 4 g of sodium hydroxide on a technical balance, placed it in a 1 L volumetric flask and refilled with distilled water to the 1000 ml mark. The exact concentration of the prepared sodium hydroxide was determined using a hydrochloric acid solution prepared from a fixed channel.

The titration results are shown in Table 5.

Table 5

Establishing the concentration of sodium hydroxide

The titratable acidity is expressed in g / dm 3 ... The titratable acidity is determined by the amount of alkali (sodium hydroxide or potassium) required to neutralize acids.

The titratable acidity is determined according to the following procedure.

Fifty ml of juice is transferred into a 250 ml volumetric flask, brought to the mark with distilled water. Then 10 cm³ is transferred with a pipette into a flask and titrated with 0.1 M NaOH solution in the presence of phenolphthalein (3 drops) until a raspberry color appears, which does not disappear within 30 seconds (the analysis is carried out 2 times).

Mass concentration of titratable acids g / dm 3 (acidity), calculated as malic acid, is calculated by the formula Xк = 100 x V x C x M x V 0 / (1000 x M 1 x V 1)

V is the volume of NaOH solution used for titration, cm³

С - molar concentration of a titrated solution of NaOH, mol / dm³

M is the molecular weight of the organic acid calculated for (malic acid) 67 g / mol

V 0 - the volume to which the sample is brought, cm³

M 1 - molecular weight of alkali

V 1 - volume of solution taken for titration, cm³

1. Results and its discussion

To determine the most popular types, we conducted a sociological survey (questionnaire in the appendix) in which 100 people from our lyceum took part. It was found that 70% of the interviewed respondents prefer juices, 20% nectars and 10% do not see much difference between nectar and juice. It was found that the leading position was taken by apple juice, it was chosen by 53% of respondents, followed by orange 44%, the remainder in 3% was divided among themselves by juices and nectars of different taste. Among the most preferred brands of juice were selected brands Dobry (35%), J7 (24%), Rich (15%), Favorite (13%), Orchard (8%), My family (5%). For our research, we have selected apple juices from these manufacturers.

Organoleptic indicators of the quality of the finished drink - appearance, transparency, color, aroma and taste are determined according to GOST 6687

The results of organoleptic indicators are presented in table 6.

Table 6

Organoleptic indicators

Of the analyzed juices in terms of organoleptic indicators, the leader is"J7" this juice has the following characteristics: transparent, intensely yellow, with an apple aroma, the taste is thick, sweet, a pleasant apple taste remains in the mouth. Juices follow"Kind" : light yellow transparent juice, has a pronounced apple smell, rich taste, harmonious in the content of acids and sugars and"Orchard" juice of natural color, well-pronounced apple aroma, well-pronounced apple taste. Further, the rating scale by taste was taken by"Rich" dark yellow juice with a sour taste and low odor, clear liquid and"Favorite" clear juice of intense yellow color. Bright apple aroma and taste. Juice got a low rating"My family" clear juice of normal yellow color. The taste and smell are not entirely natural, there is a taste and smell of apple essence.

We carried out a quantitative analysis of the acidity of the selected juices. The titration method was used. A total of 20 titrations were performed with 6 objects.

Acidity is the content of organic and mineral acids, as well as their acidic salts determined by titration in accordance with GOST R 51434-99.

The titratable acidity index shows how sour or sweet a drink is. Apple juice is highly acidic and relatively low in sugar. Therefore, to normalize the taste, it is often diluted with water and sweetened with sugar.The titration results are shown in Table 7.

Table 7

Titration results

According to the titration data, the acidity values ​​of the juices were calculated. Presented in table 8.

Based on the titration results and comparing them with the GOST data (0.3-1.4), it can be concluded that all juice samples fit the GOST scale for apple juice. We were very pleased with the data obtained, which means that these juices can be safely used in school meals.

Table 8

Titratable acidity

IV. Conclusion

Thus, as a result of the research carried out, we obtained the following results:

1. Organoleptic indicators of the quality of apple juicescolor, taste and aroma are normal. The color varies from yellow to dark yellow in different samples. Taste and aroma in all samples without foreign tastes and odors. In terms of appearance, the samples turned out to be a transparent liquid.
2. Juice received the highest organoleptic rating J7
3. The acidity of the juices is normal.

V. List of used literature

1. Analytical chemistry. Methods of chemical analysis / edited by O.M. Petrukhina M 1992
2. Biology: Encyclopedia / ed. M.S. Gilyarova, Moscow: Great Russian Encyclopedia, 2003, p. 384.
3. GOST 6687 -89. By-products of fruits and vegetables. Methods for determining organoleptic indicators
4. GOST R 51434-99 Fruit and vegetable juices. Method for determination of titratable acidity.
5. Nikiforova, N.S. Handbook on the commodity science of food products. In 2 volumes. Vol. 1: Textbook. for the beginning. prof. education / NS. Nikiforova, A.M. Novikova, S.A. Prokofiev.-M .: Publishing Center "Academy".-2008.-p.128-131
6. Handbook Chemical composition of food products / edited by I.L. Skurikhina M: Agropromizdad 1987

Internet resources:

1. Nutritional value of juices. // www.nashedelo.com.ua
2. Juices. // www.life4u.ru
3. Juice therapy. // fito-center.boom.ru
4. Organoleptic analysis diagram. // (www.cargill.ru)

VI Appendix

1. Questionnaire for the survey of students of the Lyceum

1) What do you like more?

a) Juice

b) Nectar

c) I don't see the difference

2) What juice / nectar do you prefer (one option)?

a) Carrot

b) Apple

c) Pear

d) Pineapple

e) Grape

f) Tomato

g) Orange

h) Grapefruit

i) Cherry

j) Peach

k) Apricot

l) Blueberry

m) Blackcurrant

n) Cranberry

o) Lingonberry

p) Passion fruit

q) Banana

r) Pumpkin

s) Multifruit

t) Your options: _________________________________________

3) Which brand of drink do you prefer (one option)?

a) "Kind"

b) "Favorite"

c) "Orchard"

d) "I"

e) "J7"

f) "Rich"

g) "Gardens of the bottom"

h) "My family"

i) "Favorite Garden"

j) "Tonus"

k) "Frutonyanya"

l) Your options: ________________________ _________________

2. Information about the studied juicesApple juice, sugar, citric acid, water

Russia, Moscow region., Shchelkovo, Fruit proezd

1 year

Orchard

Apple juice, sugar, glucose-fruit syrup, citric acid, water

RF, Lipetsk region, Lebedyan, st. Matrosova, 7

6 months

kind

Russia, Moscow region, Shchelkovo

3. Results of the survey

1. What do you like more?

2. Which juice / nectar do you prefer (one option)?

1. Which brand of drink do you prefer (one option)?

The acidity of the stomach is an important indicator of the state of the internal environment of a person and his health in general. In different parts of the gastrointestinal tract, acidity changes depending on the function of the site, and changes in this indicator in one direction or another can lead to the development of a whole galaxy of various diseases. Determination of gastric acidity helps in the diagnosis and monitoring of gastrointestinal diseases, and the symptoms accompanying acid-base changes in the stomach should be recognized by everyone.

Normally, the composition of gastric juice includes hydrochloric acid and bicarbonates, which have an alkaline reaction of the medium, that is, in different departments, alternately, and sometimes at the same time, the processes of acid and base synthesis take place. For the mucous membranes that line the entire gastrointestinal tract, both extremes are dangerous, since they are an aggressive environment. But together they neutralize each other, restraining the damaging effect.

Gradually passing these areas, the contents of the stomach physiologically move along the digestive tract, breaking down into molecules that the body is able to assimilate. Most enzymes are secreted in an inactive form so that the stomach wall is not digested with food, but they become active at a certain acidity for each department.

The acidity of the stomach normally varies for each section, depending on the time of day and food intake. In the stomach cavity on an empty stomach, acidity is in the range of 1.5-2 pH, and approaching the transition to the duodenum, the pH shifts to the neutral and even slightly alkaline side (up to 7.4). In the epithelial layer, acidity should be neutral.

Only if the acidity is consistent, digestion will be effective, and the gastrointestinal mucosa will remain intact.

Why do you need to maintain a certain acidity?

The oral cavity is inhabited by a huge number of microorganisms, which, with adequate functioning of the immune system, do not pose a danger to a healthy person. Mixing with food, they enter the stomach, which acts as the main defense factor against infection precisely due to the acidic reaction of gastric juice. Hydrochloric acid neutralizes most bacteria that enter the stomach, preventing them from entering the intestines, where they can be absorbed into the systemic circulation.

In the stomach, the first stage of the breakdown of complex molecules occurs under the influence of its own enzyme systems. The stomach wall is rich in glands that produce various enzymes, in particular pepsinogen.

Pepsinogen is an inactive form of the enzyme pepsin that breaks down proteins. Under the action of hydrochloric acid, inactive pepsinogen is converted into active pepsin. Hydrochloric acid is also involved in the breakdown of proteins, having an independent proteolytic effect.

Like any other acid, HCl is mildly irritating. By stimulating motility and irritating receptors, hydrochloric acid becomes a triggering factor for the movement of food from the stomach into the duodenum.

Why measure acidity?

Measurement of acidity in the stomach is prescribed for an accurate diagnosis, changes in this indicator indicate a developing gastrointestinal pathology.

Depending on the direction in which the acid-base state has shifted, you can find the cause of the disease. Only by normalizing acidity can effective therapy be achieved.

Acidity determination methods

The least accuracy and approximate information in the hospital is given by probeless method, based on the identification of different staining of urine using ion exchange resins. Acidotest has become more widespread in this line of products. The kit includes several tablets with:

• dye;
• ion exchange resins;
• stimulant of gastric acid secretion.

Resins are inert for the body and are not absorbed in the gastrointestinal tract, which means that they cannot appear in the urine, like the dye, which is in a strong complex with them. But the dye is easily displaced by hydrogen ions coming from hydrochloric acid. Depending on how many ions from hydrochloric acid have displaced the dye, the urine will be colored differently. A color scale is attached to the kit, according to which one or another condition is judged.

Probing of the stomach will more accurately tell about the state of acidity: gastric contents are sucked out, the acidity of which is measured in the laboratory. This method is not physiological, as there is mixing of fluids from different departments, which have different acidity. The result is an average figure with low reliability.

Stomach probing process

During the it is also possible to determine the acidity of the stomach by irrigating the mucous membrane with a special acidity indicator through a flexible endoscope. The method is visual and also not very accurate.

An intragastric pH meter is considered the gold standard and the most informative way to measure acidity. This method not only gives an accurate pH value, but also reflects the complete picture of the distribution of acid in the stomach in different parts of the gastrointestinal tract or even at different times of the day.

How to suspect a violation of acidity at home?

To determine the acidity of the stomach, you can use a simple test with litmus paper, which can be purchased at the pharmacy. Put the test strip on your tongue for a few seconds.

It is important to conduct the study either 2 hours after a meal or an hour before a meal. Remember that you should not drink juices and carbonated drinks on this day, they can distort the result, limit yourself to clean drinking water. It is best to repeat the experiment on different days, and then see the average result.

Litmus paper is a simple indicator for changing the pH of a medium.

Changes in the color of the paper will indicate the acid-base state of the gastric juice:

• red (or pink) color - acidic environment;
• violet is a neutral medium.

Another method is based on the psychosomatic reaction of the body. It is enough to imagine the taste and smell of lemon in your mind and listen to your feelings. Lack of discharge or increased secretion of saliva are signs of a change in the environment in the stomach.

Obviously, at home, it is impossible to accurately determine "your" acidity in the stomach. But everyone can assume a violation, it is enough just to follow their feelings during the day.

Increased acidity

Most often, an increase in pH in the stomach accompanies the development of so-called acid-dependent diseases. These include hyperacid duodenitis and gastritis, peptic ulcers of the duodenum and stomach, and GERD (gastroesophageal reflux disease).

• pain after eating (1-2 hours later);
• sour belching;
• burning and heaviness in the abdomen (heartburn);
• nausea (in rare cases - vomiting);
• a tendency to constipation.

Reduced acidity

Low acidity of gastric juice is a common pathology that is almost asymptomatic until the moment when atrophic gastritis develops. Low secretion of hydrochloric acid leads to a weakening of the antimicrobial barrier, which leads to frequent intestinal infections, weakening of gastric and intestinal motility.

Symptom complex characteristic of this condition:

• bad breath;
• lack of appetite;
• weakness, chronic fatigue;
• a tendency to constipation or diarrhea;
• anemia;
• tendency to allergic reactions;
• flatulence (increased formation of gases in the digestive tract);
• recurrent stomach upset.

How to normalize acidity?

With an increased level of acidity in the stomach, drugs of the anticholinergic group, for example, atropine and platifillin, have shown their effectiveness. The aggressiveness of gastric contents is also reduced by:

• antisecretory drugs (ranitidine, omeprazole);
• antacids (Rennie, Gastal).

Among folk remedies, potato and aloe juice, propolis tincture and natural honey have proven themselves. Carrot juice and warm milk can reduce gastric secretion and thus acidity. In addition, carrot juice reduces abdominal pain with a mild analgesic effect.

It is much more difficult to increase acidity in the stomach. Alternative medicine can also help: wormwood, calamus or peppermint. Herbal preparations from chamomile, St. John's wort and herbs (bitter wormwood) should be brewed in a thermos and taken half a glass half an hour before meals.

Drug therapy is prescribed only after a therapeutic diet has been prescribed and has had its effect. Replacement therapy includes hydrochloric acid preparations (acidin-pepsin) or drugs that stimulate the production of gastric juice. It is impossible to appoint them independently and without constant supervision by a specialist.

Nutrition with an increased acidity level

A therapeutic diet with an increased level of acidity is prescribed taking into account the degree of damage to the mucous membrane and the stage of the process.

During the period of exacerbation, first of all, it is necessary to reduce any irritation of the inflamed stomach: chemical, thermal or mechanical. Food should not be too hot or cold, spicy, salty and especially sour foods should be completely excluded from the diet. The patient should chew food well and eat small portions, but often. All products are steamed or boiled. An hour before meals, the patient is advised to drink bicarbonate mineral water.

During the period of remission, it is allowed to add carbohydrates to the diet (wheat and rye bread, cookies, crackers), lean meat, soups cooked in vegetable broth. It is still best to stick to a steamed “diet” and avoid eating spicy, salty or acidic foods. Enveloping mucous agents (natural jelly or infusions of oatmeal) have a beneficial effect.

With this patient, they conduct a sanitary and educational conversation about the dangers of alcohol and smoking, which stimulate the secretion of the stomach glands, which is unacceptable in the position of a patient with an increased level of acidity.

Nutrition with a low acidity level

Common mistakes in the tactics of treating low acidity levels are precisely the stimulation of secretion and attempts to artificially increase the acidity. In no case should this be done, since the mucous membrane is in a weakened state, you should not load the stomach even more. First of all, it is necessary to prescribe a gentle diet with easily digestible foods.

As in the case of a high acidity level, the dish of choice will be various cereals (oatmeal, buckwheat), rice, mashed potatoes. Products should be soft, uniform consistency and not hot in temperature. The patient can cook vegetable soups, steamed lean meat and fish, and even flour.
From the moment the symptoms subside, you can begin to stimulate the secretion of gastric juice. Sour fruit and tomato juices, marinades help in this. Vitamins will be useful for improving general condition and as stimulants of mucosal healing.

Vii. JUICE STUDY

To prepare the wort, you need to know how much is contained in the resulting juice acid (acidity juice) and Sahara (sugar content juice). It is necessary to know this in order to prepare wine of the desired quality, since in most cases the juices of fruits and berries contain an excess of acids and an insufficient amount of sugars.

In home winemaking, especially if a small amount of wine is being prepared, Table 2 can be used to determine the composition of the juice. If a winemaker prepares wine on a small-scale or industrial scale, or if they wish to prepare wine of very high quality, then it is better to conduct a more detailed study of the juice. (I, for example, use a table).

The acidity of the juice determined by the amount of alkali spent on neutralizing the acid contained in the juice, which is based on the properties of acids to combine with alkalis.

Fruit and berry juices contain various acids: tartaric, malic, citric, succinic, etc. As a rule, malic and citric acids prevail, in contrast to grapes, where tartaric acid occupies a dominant position (although other acids are also present, but in much smaller amounts).

When determining the acidity of the juice, the total acidity is calculated in terms of the acid prevailing in the given juice. For grape juice and wine - in terms of tartaric acid, for fruit and berry juice, as a rule, in terms of malic acid and, less often, citric acid (depending on which of them prevails in a given type of fruit and berries).

The acidity of the juice is determined by adding an alkali solution of a certain concentration (titration solution) to it. Titre is the amount of alkali in 1 ml of solution, and titration is the determination of acidity using a titration solution. The result of the reaction when alkali is added to the juice is looked at by an indicator - litmus test. When determining the amount of acid in juice or wine, a titration solution of sodium hydroxide is used.

To determine acidity, a winemaker must have: a pipette; graduated glass tube (burette); glass beaker or porcelain cup; glass rod, titration solution, litmus indicator (litmus paper, which turns blue from alkali and turns red from acid).

Pipette- a glass tube with marked divisions must hold at least 10 ml of liquid.

Burette- a glass tube with marked divisions for each 1 ml of volume up to 25-50 ml.

Titration solution... It is a solution of dry sodium hydroxide in the amount of 5.97 g., Dissolved in 1 liter of distilled water. It will take about 0.3 liters. The previously prepared solution can be stored in a glass bottle with a chemically resistant rubber stopper.

Determination of acid content.

The essence of the method consists in adding a titration solution to a certain volume of juice until the litmus paper turns blue from the resulting mixture, which will mean the neutralization of all acid in the juice with alkali. Knowing the initial volume of juice and the volume of the used alkali titration solution, and that 1 ml of alkali neutralizes 0.1% acid, it is easy to determine the acidity of the juice.

Let's take a closer look at the following example. Let's say you have apple juice available. Place a clean, dry burette vertically on the table, then carefully pour 10 ml of juice into it. This is a strictly measured amount of juice by pouring it into a glass beaker. If the available juice is brightly colored (blackcurrant, etc.), then the measured amount of juice can be diluted by pouring distilled water using a pipette (pour the contents of a pipette 3-5 times) so that the juice becomes less colored. Mix the resulting mixture of juice and water with a glass rod. This dilution of the juice will not affect the acidity index, since during dilution only the volume of the mixture will change, and the amount of acid will not change, because exactly 10 ml of juice was taken.

Then, in a glass with juice from a pipette, add the titration solution in measured portions, after each addition, mix the juice with a glass rod, and apply the drops from the glass rod to litmus paper. The red color of the litmus means that not all of the acid has yet been neutralized and therefore we add a new portion of the alkali titration solution. We will do this until the red color of the entire litmus paper changes to blue, which will be when all the acid is neutralized with alkali. Suppose we used 21 ml of an alkaline titration solution to neutralize 10 ml of apple juice, then this means that 1 liter of juice contains 21 g. malic acid, or 2.1% acid.

To determine the acidity of fermenting juice or wort, it is necessary to heat a measured amount of juice (wort) to a boil to remove carbon dioxide that has formed during fermentation and can distort these definitions.

Determination of the amount of sugar in the juice.

The total amount of sugar in juice can be determined by the specific gravity of the juice, which is based on the dependence of the density of the juice on the sugar content in it. Specific gravity is determined by weighing the measured amount of juice on an accurate balance or using a hydrometer. Before determining the amount of sugar, the juice must be filtered through a paper filter. The temperature of the juice should be 19-20 ° C.

The specific gravity of the juice is determined as follows: using a clean dry 10 ml pipette, measure 10-100 ml of filtered juice into a clean dry glass, which must be weighed before filling with juice. Then, on an accurate scale, we determine the weight of a glass of juice. Divide the weight of the measured juice by the weight of water of the same volume, the result of the division will be the desired specific gravity of the juice. To calculate the percentage of sugar in the juice, subtract 1 from the specific gravity, and divide the remaining difference by 5. The resulting figure will indicate the percentage of sugar.

For example, 100 ml of juice weighs 104 grams, and 100 ml of water weighs 100 grams. The specific gravity of the juice will be: 104 : 100 = 1.040. We subtract one from the specific gravity: 1.040 - 1.00 = 0.040, or just 40 (to simplify calculations). We divide this difference by 5 and get the percentage of sugar in the juice, i.e. 40 : 5 = 8 or 8%.

Using a hydrometer, it is easier and faster to determine the percentage of sugar. The filtered juice is brought to a temperature of 20 ° C, poured into a tall narrow vessel. Pour it so that no foam forms. A clean, dry hydrometer is carefully lowered vertically into the juice, preventing it from diving. If the body of the hydrometer, located above the surface of the juice, is moistened with juice, then the hydrometer readings will be incorrect, since the device will become heavier. It is necessary to carefully lower the hydrometer into the test juice, holding the upper part with two fingers. If the hydrometer is dipped, then the case should be rinsed with clean water and wiped dry, and the measurement process should be repeated again. The hydrometer readings should be taken so that the eye is at the level of the surface of the juice.

If the temperature of the juice differs from 20 ° C, then the temperature correction is made to the hydrometer reading. If the temperature is above 20 ° C, then the value obtained from multiplying the difference in temperature degrees by 0.0002 must be added to the hydrometer reading. For example, at 25 ° C, the hydrometer reading is 1.053, and the actual weight will be: 1.053 + (5 x 0.0002) = 1.054. Conversely, at a juice temperature below 20 ° C, the temperature difference multiplied by 0.0002 must be subtracted from the hydrometer reading.

For example, a hydrometer reading at a juice temperature of 14 ° C is 1.041. Then the value is: 1.041 - (6 x 0.0002) = 1.0398.

After making a temperature correction, the sugar content is determined by the specific gravity of the juice.

In addition to sugars, juice also contains extractives, the content of which is different in different juices. These extractives affect the accuracy of the results for determining the sugar content of the juice, allowing a deviation within 1. Therefore, when studying there are few extractive juices (for example, apple juice), 1 must be added to the sugar content by specific gravity. When calculating, use the formula:

C = (Y: 5) + 1, where C is the sugar content in the juice in% or in gp. for 100 ml of juice; Y is an indicator of the specific gravity, in which the leading ones and zeros are excluded. For example, the specific gravity is 1.041, then Y = 41, then C = (Y : 5) + 1 = 9,2%.

When determining the amount of sugar in juices of medium extractability (red and white currants, raspberries, garden strawberries, etc.), use the formula:
C = (Y: 5).

All of this juice research is essential to making quality wine. In home winemaking, especially if a small amount of wine is being prepared, you can use