Introduction

An analysis of the development programs of educational institutions that received support within the framework of the national project shows that knowledge of information technologies, the ability to take care of one's health, engage in communication, and solve problems are new components of the modern quality of education that is in demand by society. The most characteristic is the transition from the mindset to memorizing a large amount of information to the development of new types of activity - design, creative, research.

The project activity of students to master operational knowledge in the process of socialization seems to be promising for a modern school. In the twenty-first century, the volume of educational material, high requirements for the modern student and teacher push the teacher to search for innovative forms of activity, interactive methods, including the use of projects. This type of activity is more multifunctional than others.

The project method involves the use of a wide range of problem studies, the search for methods focused on a real practical result that is significant for the student and teacher, and on the other hand, a holistic development of the problem, taking into account various factors and conditions for its solution and implementation of the results.

The project activity may be preceded by a brainstorming session, during which new interesting problems for the students will emerge. During the project, students synthesize knowledge in the course of their search, integrate information from related disciplines, look for more effective ways to solve project problems, communicate with each other. Joint activity really demonstrates the broad possibilities of cooperation, during which students set goals, determine the optimal means of achieving them, and comprehensively test the competence of the individual.

Project activity clearly demonstrates the possibilities of mono- and poly-subject, individual and group projects.

The object of this work is the process of development of education as an integral pedagogical system, and the subject of this research is innovative pedagogical technologies as an integral part of the object of research.

The purpose of this work is to show that the project awakens the student to show intellectual abilities, moral and communicative qualities, to demonstrate the level of knowledge and general educational skills, goal-setting, the ability to self-education and self-organization, in project learning, priority is given to the independent work of students in a team, which contributes to their development. social consciousness.

An educational and cognitive project is a time-limited, purposeful change in a certain system of knowledge based on specific requirements for the quality of results, a clear organization, and students' independent search for a solution to the problem. For a certain time (from one lesson to several months), students solve a cognitive, research, design or other problem.

The forms of project implementation are different: it can be a printed work, an article, a report to a conference, a wall newspaper, an almanac, a multimedia presentation, a creative report.

But the main thing in all this is to gain new knowledge in the course of solving educational and cognitive problems.

Modern educational project

One of the directions of the reform of the general education school is the transition from traditional to developing humanitarian educational technologies.

Methods of activity-based organization of training are gaining special relevance. Only through active independent activity is the development of each student possible. Great opportunities for the transition from a knowledge-based learning model to an ability-based model are project-based learning that grew out of the project method.

A modern educational project is a didactic means of enhancing independent cognitive and creative activity, the formation of the student's personal qualities. The use of the project method, in particular, in mathematics lessons, allows students to form an objective system of ideas about their knowledge, opportunities and abilities to implement them.

Students master the ability not only to understand the goal of their learning, but also to set it independently, to define specific tasks, to program their own activities, to select adequate means of achieving the goal, to determine the sequence of actions, to determine the sequence of actions.

A necessary stage in the work on a project is an objective assessment of the final and intermediate results of their actions. Essential in this process is the ability to correct your actions, that is, to reconstruct these actions in such a way that the result meets the requirements. For this purpose, it is imperative to reflect on each stage of the project activity.

Thus, the basis of project-based learning is the reflexive-activity paradigm, which involves active actions of students, mandatory reflection, which leads to a conscious understanding of problems, contributes to self-development. With the reflexive-activity method of teaching, the teacher's position changes, as well as the requirements for his professional qualities. From a bearer of ready-made knowledge, he turns into an organizer of cognitive, research, independent activities of students, performing the role of a competent consultant.

Reflexive activity learning involves three main functions of a teacher.

The first and main one is the creation of conditions for the inclusion of students in independent cognitive creative activity.

The second is to stimulate a situation of success for each student.

The third is carrying out, together with the students, the reflection of the activity, the process of self-change.

The priority form of interaction in the classroom with the use of project activities is "teacher - group".

The project activity is based on collective work on solving life, by the students themselves, of the practical tasks set.

A significant part of the project activity - collecting materials, applying the results obtained in practice, the most important moments at which students learn about life and learn to apply their knowledge to it - takes place outside the walls of the school.

The laboratory for the design method is the entire surrounding life, and the teaching aid is all the surrounding objects and phenomena to be studied in connection with the intended task. Work skills, including learning skills, are acquired in the very process of work and the faster and stronger the more students are interested in achieving the intended goal.

Project-based learning is based on the independent activity of students, since true learning goes through activity. The teacher should not so much teach as give a thought, and not so much expound as direct, not so much impose, but respond to a call for leadership. The attention of students is kept tense all the time, they are required to be constantly active, they must plan for themselves a program of studies and intensively carry out it in order to successfully work on one task, to take on another. Thus, the use of project activities makes it possible to bring educational work closer to research work.

Stages of work on a project

The progress of work on a project can be defined in general terms through the following stages:

1. Preparation for work on the project:

Determination of the theme and goals of the project;

Formation of groups to work on a project;

Planning stages of work.

2. Working on a project in groups:

Work planning;

Study;

Registration of conclusions and results.

3. Presentation - project defense.

4. Project evaluation (several levels of evaluation):

Self-esteem;

Assessment of other groups;

Teacher assessment;

Assessment by a specially created group of experts.

1. Analysis of the quality of tea

2. Analysis of the quality of coffee

3. Analysis of the quality of cereals

4. Analysis of flour quality

5. Analysis of the quality of pasta

6. Analysis of the quality of bread

7. Analysis of the quality of milk and dairy products

8. Analysis of the quality of sausages

9. Assessment of the quality of canned fish and preserves

Tea quality analysis

Purpose of work: to study the distinctive features of different types, types of tea; to develop the ability and skills in identifying defects, preparing an average sample and examining the quality of tea .

Organoleptic assessment of the quality of tea (tea tasting).

Use the standards above to get the job done.

Examine and describe in a workbook the appearance of the pack, box, tile, brick. Use standards to get the job done. Examine and describe in a workbook the appearance of the pack, box, tile, brick.

Tea appearance (cleaning).

A sample weighing 100 g is taken from the average sample and poured into a thin layer on a sheet of white paper. The appearance of dry tea is determined by examining it in daylight (diffuse) or bright artificial light. When determining the appearance of dry tea, pay attention to the color, evenness, uniformity and curl of the tea leaves; in tiled and brick tea, check the integrity and strength of the tiles, the smoothness of the surfaces and the condition of the corners and edges. paper. The appearance of dry tea is determined by examining it in daylight (diffuse) or bright artificial light. When determining the appearance of dry tea, pay attention to the color, evenness, uniformity and curl of the tea leaves; in tiled and brick tea, check the integrity and strength of the tiles, the smoothness of the surfaces and the condition of the corners and edges. paper. The appearance of dry tea is determined by examining it in daylight (diffuse) or bright artificial light. When determining the appearance of dry tea, attention is paid to the color, evenness, uniformity and curl of the tea leaves; in tiled and brick tea, the integrity and strength of the tiles, the smoothness of the surfaces and the condition of the corners and edges are checked. When determining the appearance of long tea, you should also pay attention to the content of red petioles (rough stems), wood hairs, untwisted leaf blades and other impurities (small stones, fragments of glass, cement, chips, grass, etc.) in the tea.

The presence of petioles (red stems) or wood hairs in tea indicates that the tea is made from rough raw materials and is poorly sorted. The more petioles or hairs of wood the tea contains, the lower its quality.

Admixture of untwisted tea leaves negatively affects the quality of tea. Uncoiled leaves in black long tea, due to poor fermentation, retain their green color, which has a very negative effect on the aroma and taste of the tea.

Brown and reddish untwisted leaves can be found in black long tea, which is explained by the delay in processing the tea leaf, which is damaged, does not curl and does not ferment. The more brown leaves in the tea, the poorer its quality.

The admixture of foreign objects is not allowed in the tea; products clogged with foreign impurities are considered defective.

Preparation of tea infusion. Infusion, aroma and taste, color of the boiled leaf are determined after brewing the tea. To do this, weigh a sample of tea Zr with an accuracy of ± 0.1 g from a sample of 100 g and pour it into a special porcelain teapot, pour it with boiling water without refilling the teapot by 4-6 mm, cover with a lid and keep the infusion for 7 minutes for brick and 5 minutes - for other types of tea. With a shorter brewing duration, the extractive substances turn into the infusion in a smaller amount, and with a longer duration, instead of the pleasant aroma and taste of tea, the smell and taste of wood may appear.

At the end of the brewing period, the infusion is poured from the teapot into a special porcelain cup. At the same time, it is necessary to pay attention to the fact that the infusion from the teapot is completely poured out, since leaving part of the infusion in it can affect the intensity of the infusion and its extract. To do this, shake the kettle several times to completely drain the last, thickest drops of infusion. Tea analysis is carried out 1-1.5 minutes after pouring the infusion into a cup.

In the infusion of tea, its characteristics and taste are determined, and in the tea left after pouring in the teapot, the aroma and color of the boiled leaf are determined.

Infusion. When characterizing the infusion, attention is paid to its transparency, color intensity and shade. The infusion of tea should be pure; in the lower grades, turbidity is allowed. The more intensely the infusion is colored, the higher the tea is rated.

Evaluation of the infusion of black long tea is made depending on its intensity: above average, average, below average and weak. Usually the tea of ​​the highest grades has a higher average infusion. Larger leaf teas of the premium and first grade are characterized by a medium infusion, while lower grades are characterized by a weak infusion. The best is the transparent, bright color of the infusion. Brown, dark, cloudy or greenish color of black tea infusion is considered a disadvantage and indicates a violation of the technological regime. Fine tea has a more intense infusion compared to loose leaf tea.

The color of the green tea infusion should be from light green with a yellowish tint to dark yellow with a reddish tint, brick green - red-yellow, black tiled - from brown with a dark red tint to dark brown with a brownish tint, depending on the variety ...

If the color of the infusion does not meet the requirements of the standard, the tea, accordingly, receives a low rating.

Aroma and taste of tea. The aroma of tea is determined not immediately after pouring the infusion, but after 1-1.5 minutes. During this time, the boiled leaf in the teapot cools down slightly, which helps to better capture the aroma. When hot, it is impossible to detect the actual aroma of the tea. But you should also not hesitate to sample the tea for more than 1.5 minutes. The more the tea cools in the teapot, the more difficult it is to establish its aroma. If it is cooled too much (over 1.5 minutes), it is impossible to distinguish the aroma of the highest quality tea from the aroma of the inferior quality tea. Tea can have a full bouquet, delicate, delicate, pleasant or weak, rough aroma, depending on the variety.

To determine the taste, tea is drunk in small sips and the first taste sensations are recorded. The taste of the tea can be tart, not tart enough or rough, depending on the commercial grade.

The color of the boiled sheet. Place the boiled leaf on the lid of the teapot and determine its color.

The color of the boiled leaf is in direct proportion to the intensity of the infusion, aroma and taste of the tea.

When determining the color of a boiled leaf, pay attention to its uniformity: the lower the grade of tea, the less uniform the color. It can be greenish, light brown to dark green, dark brown, depending on the type and variety.

The dark color of the boiled black tea leaf is usually observed with excessive fermentation or excessive withering of the tea leaf; in case of insufficient fermentation, the color remains green. In both cases, the tea scores low.

A.S. Kucher

Mogilev 2012

1) Purpose of work: Carry out quality control of drinks.

2) Instruments and equipment: Electric stove in accordance with GOST 306, FE, sieve, electric laboratory drying cabinet with a thermostat in accordance with GOST 7365, VNIIHP VCh apparatus, laboratory lever scales in accordance with GOST 19491, desiccator in accordance with GOST 6371, porcelain evaporating cups with a diameter of 6 - 8 cm in accordance with GOST 9147 (or cups (bottles)) according to GOST 7148.

Work order

Assessment of organoleptic and physicochemical characteristics of tea

1.1 Organoleptic assessment carried out at a temperature of infusion (brewing) 65 0, comparing it with the control. The control infusion is prepared from tea of ​​the corresponding grade, which is brewed in an amount of 10 (20) g per 500 cm 3 of water, infused for 10 minutes and filtered.

The aroma and taste of the drink (subject to the rules of bookmarking and brewing rules) are characteristic for each type of tea. Correctly brewed tea is transparent. If the infusion is cloudy, its color is dull brown, it means that the tea is not brewed correctly or has been infused for a long time.

Organoleptic characteristics of the test sample:

Colour- transparent, orange-yellow shade.

Aroma and taste- typical for this type of tea.

Table 1 - Tea-brewing No. 1002

Table 3 - Content of dry substances in tea

m dry v= 20.35 g

Table 4 - Organoleptic indicators of tea quality

1.2 Determination of the freshness of the infusion. Boiling tea infusion leads to a loss of aroma, transparency and deterioration of color: from orange-yellow it turns dirty brown. Boiled tea is removed from sale and is not subject to further analysis.

A control infusion (infusion) is prepared according to recipe 1008. The investigated and control infusion is cooled to room temperature and filtered through a paper filter.

To determine the freshness of the infusion, 1 cm 3 of the filtered infusion, test and control, is poured into two test tubes. To the samples are added 2 cm 3 of a 1% solution of iron-synergistic potassium and a 40% solution of sodium hydroxide. The contents of the tubes are shaken and left for 5-10 minutes. When the infusion is boiled or dry tea is not added to it, the liquid in the test tube turns into a light yellow color, when the sleeping tea is brewed again, it turns into lemon; the liquid in the control tube is golden in color.

Table 5 - Determination of tea freshness

Continuation of table 5

1.3 Finding Burnt Sugar in Brewing Tea. Burnt sugar enhances the color of the tea infusion, thereby masking the under-investment of dry tea. The discovery of burnt sugar is based on the fact that tea tannins (unlike burnt sugar) form a precipitate with a solution of acetic acid copper.

5 cm 3 of tea infusion is poured into a dry test tube, 2 cm 3 of a saturated solution of acetic acid copper is added and the contents of the test tube are thoroughly mixed and left for 15-20 minutes.

By the color of the liquid, the presence or absence of sediment, a conclusion is made about the presence of burnt sugar in the infusion (table 6).

Table 6 - Characteristics of the strength of tea infusion according to standards

The tea infusion, in which burnt sugar is found, is removed from the sale.

The results of the experiment are shown in table 7.

Table 7 - Determination of burnt sugar in samples

Conclusion: during the experiment, it was found that sample No. 1 contains burnt sugar.

1.4Finding Baking Soda in Brewing Tea. In an alkaline environment, the color intensity of the brew increases. Therefore, adding baking soda to the brew can mask the under-supply of dry tea or the use of dormant tea.

The tea leaves are cooled to room temperature. A drop of tea leaves is applied to a strip of universal indicator paper. Baking soda will turn the test paper green. In the absence of soda in the infusion, the yellow color of the paper will not change.

Table 8- Content of baking soda in tea

Conclusion: during the experiment, it was found that sample No. 2 contains soda.

Similar information.

Tea quality indicators. Various methods of laboratory research (chemical and luminescent analyzes, gas chromatography and spectrometry, etc.) are used to assess the quality of tea, conduct an examination and in-depth study of its properties.

However, the organoleptic research of tea is still decisive in assessing its quality.

The organoleptic properties of tea are determined by experts in the field of tasting evaluation - titters, using a 10-point system (see Table 7). According to this system, the lowest-grade teas (domestic and foreign) are estimated at only 1.5 points, and the highest-quality ones - at 5.5 points and higher. A tea score of 8-10 points is still considered unattainable. The highest quality teas, called Unique (for example, the best teas samples Indian Darjeeling tea or Ceylon Nyur-Eli), very rarely receive a score of up to 7 points for their unique aroma and taste. The evaluation of the usual higher grades is much lower. So, the highest grade of the I category of factory tea can have a score of 6.25-8.00, the highest grade of the II category (B-2) - 5.25-6.0, and the 1st grade - 4.75-5, 0.

The organoleptic method for evaluating tea is so far the only express method that allows determining the entire set of properties of tea within 1-2 minutes.

According to GOST, the organoleptic assessment of tea is carried out according to the following indicators: aroma and taste, transparency and intensity of infusion, color of the boiled leaf, appearance (harvesting) of dry tea.

To test the quality of 3 g of tea, 130 ml of freshly boiled water with a pH of 6-7 is poured into a teether teapot and covered with a lid. After a 5-minute infusion (brick tea is infused for 7 minutes), the extract without tea leaves is poured into a special white porcelain cup and the color and intensity of the infusion are determined. The color of the infusion gives an idea of ​​the type of tea (black, green, yellow, red) and its varieties (brick and slab tea differ from baikh tea in the specific color of the infusion). When assessing the color of the infusion, attention is paid to its correspondence to the type of tea, density, intensity, brightness. Bright color and always accompanying transparency are a reliable sign of high quality tea, which cannot be said about color. Pressed teas do not give a bright infusion due to the large amount of suspended particles in them. A dark, densely colored, but dull opaque infusion is a sign of poor quality tea. In an alkaline environment, the brightness and transparency of the tea infusion disappear and a brown color appears.

To determine the taste, a little tea is sipped from a cup, and, without swallowing, rolled in the mouth, evaluating the taste sensations. The astringency and fullness of the taste of the infusion are signs of high extractability of teas, their high P-vitamin activity. If the astringency is not sufficiently pronounced, the tea has an "empty", "flat" taste characteristic of over-fermented teas.

The most important indicator of the quality of the infusion is its aroma, which is formed in the first one and a half to two minutes after brewing. Aromatic substances are concentrated in the foam on the surface of the infusion. Due to the volatility of the tea essential oil, the aroma of the infusion should be determined no later than 5 minutes after the infusion, that is, immediately after draining the infusion. To do this, the kettle with the boiled leaf remaining in it is brought to the nose and, strongly drawing in air, the smell is assessed. In tetester practice, a special terminology has been adopted to determine the aroma of benign tea: rosaceous, almond, honey, citrus, a mixture of strawberry, geranium and black currant odors, etc. Organoleptically, undesirable odors are also detected in the aroma of tea, which are the result of a violation of technology or improper storage: smoke, hotness, herbaceous odor, dampness, mustiness, mold, acid and various odors.

A reliable idea of ​​the quality of tea is given by the assessment of the color of the boiled leaf. To do this, turn the teapot over on the lid and, squeezing the remaining infusion from the boiled leaf, determine the color of the leaves and the uniformity of their color. High quality black long tea has a boiled leaf that has a bright copper color. Dark brown, green and dull shades of the boiled leaf color are considered defects.

To assess the appearance, average samples are poured onto clean sheets of paper and visually determine the May group (leafy or small), the uniformity of color and the degree of curl of the tea leaves, the presence of tips (golden tips - flash buds), indicating the high quality of the tea, the presence of stems and tea dust typical for low grades of tea from late autumn harvest raw materials.

When assessing the quality of tea according to the current standard, moisture, mass fraction of water-soluble extractives, metal impurities are also determined. For a more complete characterization, in addition to standard indicators, ash content, the content of caffeine, tannin and other components are determined.

UDC 338.24

TASTING AS THE BASIC METHOD OF ORGANOLEPTIC EVALUATION OF TEA QUALITY

Kovalenko Tatyana Dmitrievna Penza State Technological Academy

Penza, Russia

Tasting as the main method of sensory evaluation complements objective methods of tea quality control. Organoleptic indicators of tea quality include: appearance, brightness and intensity of infusion, taste and aroma, color of the boiled leaf. The infusion, aroma, taste and color of the boiled leaf are determined after brewing the tea. Processing of the tasting results includes the calculation of the arithmetic mean of indicators, standard deviation and complex indicators of the quality of tea, taking into account the weighting factors. Based on the results of the organoleptic assessment of the quality of the samples, it is possible to draw conclusions about the quality of the tea.

Tasting; organoleptic quality indicators; falsification; average sample; hitch; quality categories

Tasting; organoleptic quality indicators; falsification; average test; a hinge plate; quality categories

The main method for assessing the quality of tea remains organoleptic, that is, tea tasting. Tasting does not exclude, but complements the objective methods of controlling the quality of tea. Although the subjective factor is present, it is not decisive, therefore the tasting method is quite suitable not only for assessing the quality of various batches of industrial products, but also in scientific research. To improve the accuracy of assessing tea, each sample is offered to be tested by a group of tasters, and the resulting scores are averaged.

Organoleptic indicators of tea quality include: appearance, brightness and intensity of infusion, taste and aroma, color of the boiled leaf. In appearance (harvesting), ready-made green tea is smooth, uniformly twisted, tea leaves of various sizes (depending on the type of leaf). It has a delicate, delicate, characteristic green tea, pleasant, tart taste. Its infusion is transparent, lemon-colored. The color of the boiled leaf is uniform, with an olive greenish tint.

To carry out the analysis, a sample weighing 100 g was taken from the middle sample and poured into a thin layer on a sheet of white paper. The appearance of the tea was determined by inspection in ambient daylight or bright artificial light. At the same time, attention was paid to the color, evenness, uniformity and degree of curl of the tea leaves. The presence of petioles (red stems) or wood fibers in tea indicates that the tea is made from rough raw materials and is poorly sorted.

The infusion, aroma, taste and color of the boiled leaf were determined after brewing the tea. To do this, a 3 g sample of tea was weighed on a technical balance and poured into a Titestor porcelain teapot with a capacity of 125 cm3, after which it was poured with boiling water, without refilling the kettle to the top by 4-6 mm, and quickly closed with a lid, after 1-1.5 minutes ... proceeded to define the aroma. To determine the taste of the infusion, a little tea was sipped from a cup and, without swallowing, rolled in the mouth, evaluating the taste sensations. The astringency and fullness of the taste of the infusion is a sign of extractiveness and high P-vitamin activity of the tea. If the astringency is insufficient, the tea tastes empty. An infusion devoid of astringency is considered "watery" (low content of extractives in raw materials, weak leaf curling, absorption of excess moisture by tea). During the research, we used a special tea utensil - gaiwan (porcelain, made in China, volume 125 ml. And a tea tool.

Chaou or gaiwan is a miniature tea brewing set. Includes cup, lid and saucer. Brewing in chaou is used when you need to taste tea, as well as for everyday tea drinking. A handy item for quick tea brewing. This is an opportunity to look at the brewing tea leaves and smell them. Any tea can be brewed in a chaou. Brewing rules in gaiwan:

Heat the chaou with boiling water.

Pour tea leaves into chaou.

Rinse the tea leaves and drain the water immediately.

Pour water 2/3 up the side of the cup.

Wait 30 seconds, pour the tea.

Serve tea.

For various actions with tea during tea drinking, various tea devices have been used since ancient times. They are all called chaju. The metamorphoses of time influenced the variety of forms of the tea instrument. The composition of the set of tools also changed at different times, but at the moment the most common set that we are describing has developed. A spoon is used to transfer tea from a caddy (Cha Yeguan) to Cha He. A needle (Cha Zan) is a wooden needle with a plastic or bone tip. It is commonly used to clear stuck tea leaves in a teapot. However, it must be remembered that the needle is used only in those teapots that do not have a mesh inside, or this mesh consists of large holes. An attempt to apply a needle to teapots of modern designs, with careless movements, can lead to its damage. In some sets, the needle and spatula are combined - on one side a needle, on the other a spatula. The funnel (Cha Xianglo) is used to prevent tea from spilling past the small teapot. Tongs (Jiazi) are designed to take hot cups for rinsing them, to get out the sleeping tea leaves.

The simplest methods of processing the results of tasting with a small number of experts (7 people) included calculating the arithmetic mean of indicators, standard deviation and complex indicators of the quality of tea, taking into account the weight coefficients. The quality categories of green tea are presented in Table 1.

Low 1-2

Below average 2.5-3

Average 3.25-4

Good average 4.25-5

Good 4.75-5

Above good 5.26-6

Highest 6.28-8

First, the assessments of experts, who were tasters, were averaged according to individual indicators, they were entered into summary sheets for each sample and the arithmetic mean value of estimates of single indicators (in points) was calculated using the formula

where I x is the sum of the assessors' assessments for a specific indicator (aroma and

taste, infusion, etc.) of one tea sample, points; n is the number of tasters.

To characterize the spread of the totality of tasters' assessments, the standard deviation was determined for each unit indicator according to the formula:

where I хг2 - the sum of the squares of the assessors' assessments, points;

х2 - the square of the average value of the indicator estimates, points.

The standard deviation S characterizes the consistency of expert opinions provided that the analyzed samples are homogeneous. Grades are unambiguous, S on a 10-point scale does not exceed ± 1 point. The results of testing the point scale are shown in Table 2.

table 2

Tasting sheet for organoleptic evaluation of the quality of green tea

No. Indicator Ko Numerical Characteristics of quality levels

n / and quality ef value of green tea

n phi levels,

t weight ohms

1 Aroma and taste 0.3 5 9-10 7-8 6 5 4 3 2 1 Sufficiently full bouquet, very delicate delicate aroma, piquant taste pleasant with astringency Full bouquet, delicate, delicate aroma, pleasant taste with astringency Delicate aroma, pleasant with astringency taste Pleasant aroma and rather tart taste Pleasant aroma and tart taste Weak aroma, insufficiently astringent taste Very weak aroma, insufficiently astringent taste Rubish aroma, slightly perceptible tart taste

2 Infusion 0.2 9 - 10 7 - 8 6 5 4 3 2 1 Transparent, olive, with a yellowish tinge Transparent, light green, with a yellowish tinge Transparent, light green with a yellowish tinge Transparent, light yellow Transparent, light yellow with a pink tint Yellow with a reddish tint, not transparent enough Yellow with a red tint, not transparent enough Dark yellow with a reddish tint, dull

3 Color of boiled leaf 0.1 5 9 - 10 7 - 8 6 5 4 3 2 1 Fairly uniform, with a greenish tint Uniform, with a greenish tint Uniform, with a greenish tint Insufficiently uniform, with a yellowish tint Insufficiently uniform, with a light yellow tint Not uniform , with a yellowish tinge Heterogeneous, yellow Heterogeneous, dark yellow

4 External 0.3 9 - 10 Fairly even, homogeneous, good

twisted view

(cleaning) 7 - 8 Smooth, uniform, well-rolled

6 Smooth, uniform, twisted (sheet); medium-leaf - smooth, twisted, with a lamellar

5 Not flat enough, twisted

(sheet); medium leaf -

not even enough

twisted or lamellar

4 Insufficiently straight, twisted

3 Uneven, insufficiently twisted

2 Uneven, poorly twisted

1 Uneven, tea leaves are very poorly curled

The results of organoleptic assessment of the quality of samples of green Chinese

tea was drawn up in table 3.

Table 3

Organoleptic assessment of the quality of green tea samples

Sample No., name Quality indicators Weight coefficient Numerical value of levels, points (average score) Generalized quality indicator, points Quality category, grade

1 "Kudin Aroma and taste 0.35 1.1

middle lis Infusion 0.20 1.0 1.76 lowest

product "Boiled color 0.15 2.0

Appearance 0.30 2.9

2 Aroma and taste 0.35 2.0

"Green Infusion 0.20 5.1 3.12 medium

pearl "Boiled color 0.15 3.3

Appearance 0.30 3.0

3 Aroma and taste 0.35 2.1

"Green Infusion 0.20 5.0 3.50 medium

leaf Color boiled 0.15 5.0

Appearance 0.30 3.3

4 Aroma and taste 0.35 1.7

"Eyelashes of beauties" Infusion The color of the boiled leaf Appearance (cleaning) 0.2 0.15 0.30 5.1 3.0 2.3 2.76 below average

5 "Gunpowder Aroma and taste 0.35 2.4

slightly scruff Infusion 0.20 5.3 3.52 medium

cured "Boiled color 0.15 4.0

Appearance 0.30 3.4

6 "Gunpowder Aroma and taste 0.35 4.0

silvery Infusion 0.20 5.0 4.14 medium

th "Boiled color 0.15 3.4

Appearance 0.30 4.1

7 Aroma and taste 0.35 2.4

"G anpaud Infusion 0.2 5.0 4.21 medium

ep "Boiled color 0.15 4.4

Appearance 0.30 5.7

8 Aroma and taste 0.35 5.4

"Green Infusion 0.20 5.1 4.94 good

spirals "Boiled color 0.15 3.6 medium

Appearance 0.30 5.0

9 Aroma and taste 0.35 6.0

Spirals Infusion 0.20 4.0 5.30 above

Jade "Boiled color 0.15 6.0 good

Appearance 0.30 5.1

10 "White Aroma and taste 0.35 5.0

monkey "Infusion 0.20 5.6 4.60 good

Boiled color 0.15 3.7 medium

Appearance 0.30 3.9

11 Aroma and taste 0.35 5.0

Green Flask 0.20 4.9 5.22 above

Yunnan Color boiled 0.15 6.6 good

Appearance 0.30 5.0

12 "Temple Aroma and taste 0.35 1.4

sky »Infusion The color of the boiled leaf Appearance (harvesting) 0.20 0.15 0.30 5.0 3.7 5.4 3.67 medium

13 Aroma and taste 0.35 3.6

"Nine Infusion 0.20 5.0 4.50 good

dragons Boiled color 0.15 4.1 medium

Appearance 0.30 5.4

14 Aroma and taste 0.35 1.7

"Kudin" Infusion 0.20 2.0 2.17 lowest

Boiled color 0.15 2.0

Appearance 0.30 2.9

Samples No. 9; 11 have a quality higher than good, which corresponds to the Russian analogue as the highest grade.

Samples No. 8; ten; 13 are of good average quality, which corresponds to the Russian analogue as the first grade of I and II categories.

Samples No. 2; 3; 5; 6; 7; 12; are of average quality, which corresponds to the Russian counterpart, second grade.

Sample No. 4 has a quality below average, which corresponds to the Russian analogue as the second grade, III category.

It is known that obtaining a red leaf color in green tea production is undesirable. This may be due to incomplete inactivation of the enzyme complex, as a result of which the oxidation of tannins occurs, and is also associated with a violation of the duration of heat treatment of green tea leaves with a high moisture content, which leads to a decrease in the aromatic and taste characteristics of the finished tea, an increase in its color; as a result, the infusion of some tea samples had a pink tint (for example, sample no. 9).

Samples No. 1; 14 are of the lowest quality, which corresponds to the Russian analogue as the third grade. This low quality of green tea samples can be explained by two reasons: qualitative falsification; long shelf life, as a result of the aging process during the oxidation of the substances of the tea leaf.

Bibliographic list

1.GOST 3716-90. Bulk green tea. Technical conditions.

2.GOST 1936-85. Tea. Acceptance rules and methods of analysis.

3. Elizarova L.G. Examination of the quality of tea. - M .: Moscow Higher School of Expertise, 2001. - 43 p.

4. Homeland T.G. Sensory analysis of food products. - M .: ACADEMA, 2004 .-- 208 p.

5. Khoperiya R.M. Tea production technology. - M .: Agropromizdat, 1988 .-- 160 p.

The main indicators of the quality of green tea are:

Aroma and taste of tea;

Appearance;

Infusion color;

The requirement for organoleptic characteristics of green tea in accordance with GOST

Sampling and quality assessment

Sample No. 1. Greenfield green tea, bouquet variety, large-leaf, net weight 100g, manufacturer: LLC "Orimi Trade".

Sample No. 2. Tess lime. Long green tea with citrus zest, flower petals and lime scent in bags. Ingredients: long green tea, lemon sorghum, rose hips, citrus peel, calendula petals, natural lime flavor. Manufacturer: LLC "NEP".

Sample No. 3. Flavored green tea LIPTON.

Ingredients: long green tea, osmanthus and pear flavor. Manufactured by LLC "Unilever Rus"

Conclusion: In samples No. 2 and No. 3, the type of tea is not indicated. Sample №1 corresponds to GOST in all respects, №2 and №3 also correspond to GOST and belong to the third grade.

Output

Green tea, which until recently was considered an oriental exotic, is gaining more and more popularity among tea lovers. In Russia, back in the 17th-18th centuries. green tea brought from China was quite widespread, but then it was replaced by black tea.

Green and black tea are made from the same tea leaves, but the difference in their production technology determines their different biological value and taste. To obtain green tea, the raw material is subjected to heat treatment, in which the enzymes of the tea leaf are killed, which makes it possible to preserve the substances contained in the tea leaf from oxidation. Therefore, in terms of chemical composition, green tea is closer to the "natural" tea leaf. It does not form dark-colored phenolic compounds. Green tea is very rich in vitamins . In my coursework, I studied the assortment of green tea in the Magnit and Dixy stores, I learned that these stores have a fairly wide range of green tea. I found out that the main manufacturers on the market are: LLC "Orimi Trade"; LLC "Uniliver Rus"; LLC "NEP"; LLC SDS-FOODS; LLC "Baltic Resource". Then I studied the main indicators of green tea, made a selection of samples of the main manufacturers for comparative characteristics. I also studied the organoleptic indicators of green samples I selected, we can make the following conclusion: in samples No. 2 and No. 3, the type of tea is not indicated. Sample №1 corresponds to GOST in all respects, №2 and №3 also correspond to GOST and belong to the third grade. Having studied the assortment of tea, I found out that a huge number of tea manufacturers are competing in the world market, and the assortment of commercial teas is constantly being updated and expanded.