In the laboratory uses chemicals, electrical equipment and appliances, so students should be extremely careful and cautious in their implementation.
METHODICAL INSTRUCTIONS
for execution of laboratory works to the discipline
"COMMODITY RESEARCH OF PROCESSING PRODUCTIONS PRODUCTS"
Shymkent – 2017
 |
“MINISTRY OF EDUCATION AND SCIENCE OF THE
REPUBLIC OF KAZAKHSTAN”
M. Auezov “SOUTH KAZAKHSTAN STATE UNIVERSITY”
Faculty: “LIGHT AND FOOD INDUSTRIES”
Chair: “FOOD ENGINEERING”
METHODICAL GUIDELINES
for execution of laboratory works to the discipline
"COMMODITY RESEARCH OF PROCESSING PRODUCTIONS PRODUCTS"
for Bachelor's students (English groups) specialties:
5B072800 – “Technology of processing productions”
Tuition form – Full time
Shymkent – 2017
UDC 663.4 (083.13)
The composer: Arapbayeva D.M., Gabrilyants E.A.,Mailybaeva E.U. Methodical instructions for performance of laboratory works on discipline «Сommodity research of processing productions products». (Methodical instructions are intended for students of specialty 5B072800-Technology of processing productions)
Instructions has been compose according to requirements of the curriculum and the program of discipline «Сommodity research of processing productions products» and include all things needed information on performance theme of laboratory researches.
Methodical instructions are intended for students of specialty "5B072800 Technology of processing production".
Reviewer: Kanseitova E.T. Candidate of Agricultural Sciences, senior teacher, M. Auezov SKSU
Discussed and approved for publication at the chair “Food engineering” meeting (Minutes # ___ «___»________2017) and by theof higher school “Textile and Food Engineering” (Minutes # ___ «___»________2017 )
Recommended by session of Methodical council of M. Auezov South Kazakhstan State University (Minutes # ___ «___»________2017)
© M. Auezov South Kazakhstan State University, 2017
Responsible for publication Arapbaeva D.M.
Table of Content
| Introduction | |
| “Technical Safety Rules in the laboratory” | |
| Laboratory work #1. Organoleptic and physical-chemical methods of quality estimation of food | |
| Laboratory work #2. labeling of consumer and transport packaging | |
| Laboratory work #3. Codes of various food products | |
| Laboratory work #4. Sensory evaluation of the quality of grain | |
| Laboratory work #5. Features assess the quality of certain types of cereals | |
| Laboratory work #6. Evaluation of the quality of flour | |
| Laboratory work #7. Analysis of pasta. Assortment and organoleptic estimation of pasta | |
| Laboratory work #8. Analysis of bread and bakery products. Analysis of biscuits. | |
| Laboratory work #9. Exploring the range and quality assessment of confectionery products (candy, sweets, chocolate). | |
| Laboratory work #10. Assessment of the quality of confectionery | |
| Laboratory work #11. Assessment of the quality of soft drinks | |
| Laboratory work #12. Assessment of the quality of beer | |
| Laboratory work #13. Assessment of quality liquors | |
| Laboratory work # 14. Determining how falsification of food raw materials and products | |
| Laboratory work # 15. Receptions falsify identification of contaminants in food raw materials and products. | |
| Literature |
Introduction
Commodity research of processing productions products discipline, studying consumer characteristic of goods. For given sciences special importance have a research of the consumer cost goods. Any goods possess the cost and consumer cost. The amount of the public necessary labor, spent on production of goods, defines the value of his cost. Usefulness of goods, ability to satisfy some need of the person, is identified the consumer cost. The consumer cost of goods is conditioned his characteristic. Under characteristic of the product understand the objective particularity, which reveals itself under her creation, usages and consumption. The characteristic of goods can be as natural, so and gained in process production, storage and realization.
The purpose of discipline is a study student foodstuff, their useful characteristic, natures and composition, importance for person, different acceptance of their use, regime and ways of storage, methods of the checking quality, packing and transportation.
The primary task of discipline "Commodity research of processing productions products» consists in study factor shaping and conservations quality of foodstuffs. Besides task science of commoditiesis a study of the particularities to technologies production food goods for clarification of the reasons stipulate their quality and differences between separate sort, as well as change, occurring in commodity in process of his motion from producer to user.
The study science of commodities necessary future specialist bachelor to technologies processing production to save nourishing value of the food products, it is correct to choose the most rational for given type cheese way his culinary processing, skilled form the ration of the feeding for different contingent of the population. The knowledge’s of the chemical composition of the products will help it is correct to understand essence occurring under their culinary processing the change. The products, falling into ration of the feeding must contain the material required for reception of the energy, metabolism, and buildings of the fabric human organism.
Laboratory studies should be closely linked with the theoretical and practical training course "Commodity research of processing productions products."
On the laboratory works student reinforces the theoretical knowledge, acquires practical skills for the study of technology for the individual process stages. Thus student will form research skills to analyze the quality of raw materials and products.
“Technical Safety Rules in the laboratory”
Lab Reports
· Must be word handwriting processed
· Title page must show name of University, faculty, group; name of course, theme of lab work.
Name of Author and name of Instructor, date.
ABSTRACT:
State what was done, how it was done, major results, and conclusions in 300 words or less.
Laboratory work #1
Refractometry
Objective: To examine the device, the operating principles of refractometer master refractometric method of quality control of food, build skills use of refractometric methods for quality controlfood products.
Necessary chemicals and glassware:
distilled water, alcohol, glass rods, tubes stoppered, graduated pipettes 10sm3, pear rubber,conical flasks 100sm3.
Instruments: universal laboratory refractometer РПЛ-3, refractometer ИРФ 454-Б2М.
Refractometric analysis is widely used in the study foods such as fats, tomato products, jam, jam, juices, etc. Refractometric analysis is based on measuring the rate refraction (refraction) of substances which are judged on the nature of substance, its purity or content in the solutions.
Refraction - the phenomenon of refraction of the light beam at the interface two media of different optical density. The phenomenon of refraction, or the refraction of the light beam, there is at the boundary between two media, if media have different densities.
Refractometry - is the measurement of light refraction. Quantitatively refraction estimated from the corner or the index of refraction of light.
Refractometric method of analysis - a method that is based on depending on the angle and refractive index of the composition of the system, because each system is different specific optical density. Refractometry is based on the measurement of relative performancerefractive index materials.
Control questions
1. Principle of indirect methods the determination of moisture.
2. In what the conditionality of the method of desiccation?
3. Deficiencies in the accelerated methods of desiccation.
4. How is achieved the process of drying according to the accelerated method?
Laboratory work № 3
Laboratory work #4
Work sequence
100 whole grains without selection are allocated from grain party. Each grain is across cut by razor blade, and then it is divided to one of three vitreousness group. Then quantity of grain in every group is calculated. General vitreousness is defined in percentage to 100 grains.
Vitreousness of grain may be defined with diafanascope by viewing of 100 grains. Badly transparent grains is recommended to cut.
The differences between two parallel definitions are supposed no more than 5 %. Wheat with vitreousness low 40 % is considered as low-vitreousnessed; from 40 up to 70 % is middle-vitreousnessed, more than 70 % is high- vitreousnessed.
Notes in laboratory magazine:
quantity of vitreous grains................................units
quantity of partially vitreous grains………..... units
generalvitreousness…………………............... %
Report
In accordance with performed work students draw a conclusion and journalize.
New words:
suitability – пригодность
contamination – засоренность
vitreousness – стекловидность
fibrin (gluten) - клейковина
hoodness – пленчатость
eaten away – изъеденное
grain-unit – «натура» зерна
bulk - насыпной
above – выше
render - оказывать
density of stacking – плотность укладки
govern – влиять на
lumps of ground – комочки земли
shingle – галька
raise – повышать
decrease – уменьшаться
execute - выполнить
wrinkled – сморщенный
Control questions:
1. What is vitreousness of a grain?
2. Technique of moisture content definition.
Laboratory work #5.
Theoretical part
Party are considered the blocks of one designation, manufactured by enterprise for one change, with the mass not of more than 1 t. Of each party they select all-level sample - not less than 0,5 kg - by the groove of articles of 5 places in an equal quantity. 10-15 blocks are separated from the all-level sample for the physic chemical analysis.
The number of pieces of blocks in 1 kg determine on the all-level sample, color, smell, taste and exterior view - organoleptically. Blocks must have the form, provided by technological instructions. Brittleness is set to breaking not less than two blocks from the represented model.
The acid test
10 g of the ground test is introduced into the dry Erlenmeyer flask. Then from preliminarily measured 100 ml of water (at a temperature of 18-25ºC into the flask pour about 30 ml and they intermix before obtaining of uniform mass. Remaining water is added after this; again they shake up, following then so that it would not remain on the walls of the sticking particles of the analyzed test. Mixtures give to be defended by 15 min, pour the liquid through the close-meshed screen or gauze into the dry vessel, 25 ml of filtrate select from it, they add 5 drops 1% - GO of the solution of phenolphthalein and titrate 0, 1 n. by the solution of alkali before obtaining of the pink dyeing, which does not disappear during the minute. Titration continues, if during the minute painting disappears and does not appear from the addition of 2-3 drops of indicator.
For the expression of acidity in the degrees a quantity of milliliters, gone for the neutralization alkali, measured with accuracy to by 0, 1 ml, they multiply by 4. Eventual result expresses as the mean arithmetic of two titrations, the divergence between which there must not exceed 0, 1 ml.
Divergence as results of acid test in the different laboratories in one and the same test must be not more than 0, 5 deg.
The obtained results compare with the indices, regulated in the All-Union State Stan.s to the appropriate articles.
Control questions:
1. The determination of a quantity of scrap and crackers of the reduced size
2. The determination of swelling
3. The determination of moisture content
Laboratory work #6
Theoretical part
Flour is the powder product, obtained via the grinding of grain.
Flour is subdivided into the forms, the types and the sorts. Form is determined by cereal crop, from which is obtained the flour.
Flour is distinguished by the kind of cereals, by the nature of grinding, by the output, by the type.
From the organoleptic indexes most important are the color, smell and taste. Under laboratory conditions determine humidity, acidity, coarseness of grinding, quantity and quality of the gluten of wheaten flour, impurity content and infection by storehouse wreckers.
Materials and the equipment
- a copper or porcelain mortar, a laboratory mill, a sieve with apertures in diameter 1мм, metal weighing bottles in diameter 48mm and altitude 20mm, crucible pincers, an exsiccate, paper, hot water;
- Electric drying cupboard СЭШ-1.
Method of performance
Determination of color.
The color is determined organoleptically on the standard: the test of flour, poured on the bright sheet of paper, is examined with the day scattered light or with the sufficiently bright artificial lighting.
Determination of humidity.
The standard method of the determination of humidity content of flour is the desiccation of the hinges quantities of flour in the electrical cabinet drier СЭШ-1.
Preliminarily they dry and calibrate metallic weighing bottles with the diameter of 48 mm and with the height of 20 mm with an accuracy to of 0,01 g. From the selected and thoroughly mixed test of flour into the weighing bottles they weigh out on the counterbalances of the hinge quantity of flour near 5 g with an accuracy to of 0,01 g.
Cabinet drier preliminarily they heat to 130°C and then 10 weighing bottles with the hinges quantities of flour rapidly are placed in it, placing them on the taken covers. Desiccation in the cabinet is conducted during 40 min. Thermometer bulb must be located at a distance by 10 mm from the upper edge of weighing bottles.
After 40 min the weighing bottles with the hinges quantities take out from the cabinet by crucible tongs, they cap and transfer into the exsiccate to the complete cooling approximately on 20-25 min.
After cooling of weighing bottle they weigh also by the difference between the mass of the hinge quantity before and after of desiccation, initial hinge quantity referred to the mass, humidity W is determined, expressing it in %. Calculation they conduct with accuracy to 0, 1 according to the formula:
(a - b)
W= ------------ . 100
a
where: a - mass of the hinge quantity of flour to the desiccation, g;
b - mass of the hinge quantity of flour after desiccation, g.
Arithmetic mean of two parallel determinations they assume as the index of the humidity of the tested test of flour.
Materials and the equipment
- Counterbalances, Erlenmeyer flask by the capacity of 100-150 ml, distilled water,
1%- foot alcoholic solution of phenolphthalein, 0, 1 n by the solution of alkali.
Method of performance
Determination of acid.
This index characterizes first of all the degree of the freshness of flour.
Take 5 g of flour, weighed on the counterbalances. They pour out into the Erlenmeyer flask by the capacity of 100-150 ml with the preliminarily filled into it distilled water in a quantity of 50 ml. Contents of flask they shake up during approximately 3 min so that entire flour would be moistened well by water. The adhered to the walls particles of flour, as far as possible, they wash off by the distilled water. Then they add 5 drops 1%- foot alcoholic solution of phenolphthalein and titrate 0,1 n by the solution of alkali before obtaining of the weakly-pink dyeing, which does not disappear during 1 min.
Acidity X determines with accuracy to 0, 1° according to the formula:
N • 100
X=----------- K
A • 10
where N - volume of the alkali, spent for the titration of 100 g of flour, ml;
A - mass of hinge quantity, g;
K - correction factor for the caption of 0,1 n of alkali;
10 - conversion factor of 0, 1 n of the solution of alkali to 1 n.
With the hinge quantity accurately of 5 g the value of the acidity of flour is obtained by the multiplication of the spent number of milliliters of 0, 1 n of alkali by 2 and by the correction factor for the caption of alkali.
Note: For the expression of acidity in the degrees a quantity of spent by 0, 1 n alkali they multiply by 2.
Control questions
1. What organoleptic indexes are characteristic for the flour?
2. What does characterize the acidity of alkali?
3. What units are expressed the index of acidity?
Laboratory work #7
Theoretical part
Macaroni products are value food product. They have highfood value, as for their manufacture the wheaten flour with the large content of proteins is used. Energetic value of macaroni is 3600 kcal for 1 kg of product, from which about 96 % is digested.Macaroni products can be long stored at normal conditions, they also are transportable. Advantage of macaroni is also fast and simple cooking of various courses from them.
The macaroni production consists of following operations: dough preparation, forming, handling (cutting and putting on dry surfaces), drying. Macaroni dough composition is simplest and consists of floury and water. Semolina of hard wheat should be used to produce macaroni of high quality. Macaroni dough is not being exposed to leavening and fermentation.
Eggs, dairy products and tomato paste as the flavouring additives are added to increase food value to some grades of macaroni.
Depending on form the macaroni products are divided into 4 basic types: tubular (macaroni, elbow products, feathers), vermicelli (thin web, ordinary web,dilettante web), noodles (narrow, wide, goffered, long), figured products (ears, shells, semolina, grains, alphabet, figures, stars and so on).
The techniques of the work performance:Measuring cylinder (500 ml), saucepan, boiling water (600 ml), macaroni (50g), scales.
Control questions
1. Technological process of macaroni production
2. Types of macaroni products depending on form
3. What flour is used for macaroni manufacture?
Laboratory work #8
Theoretical part
Biscuit is high-caloric product prepared from flour and other materials. Biscuit contains proteins, sugar, fat, starch and so on. Caloric value of biscuit is about 4500 kcal/kg or 18.84×106Dj/kg.
Biscuits are produced in two kinds: sugary and prolonged. Sugary biscuit is brittle, crisp, with well sponginess, water absorptionand soft structure.Prolonged biscuit is harder, less brittle and porous, worse absorbs water.
Differences in biscuit properties are achieved by various quantity of sugar and fat and various technological conditions for dough preparation. At mixing of sugary dough the swelling of fibrin proteins is limited (more quantity of sugar and fat, less humidity and temperature, less duration of mixing).
At preparation of prolonged doughthe full swelling of fibrin proteins is achieved. Quality of biscuit is evaluated by average test and is distributed for all production.
The techniques of the work performance: technical scales, drying case.
Control questions
1. Kinds of biscuits, their characteristics.
2. What are organoleptical indexes of biscuits?
Laboratory work 9
Materials and the equipment
- Metal forms, the cylinder with strands, glass plates, device Valenta, a cup, device ВЧМ, weighing bottles, СЭШ.
Method of performance
Definition of fastness of fruit candyjell
For definition of strength of gel prepare a sample of the standard form - in the form of cylinders, in height 3 s-m and 4 see diameter For this purpose fruit candy mass mould in special forms; the form represents the metal stria incurvated in the form of the cylinder - tubes, in height 3 s-m and 4 see diameter. Cylinders tie with a thread that they conserved the form, and put on glass plates. Then in them pour hot fruit candy mass (to edges). To samples yield to insist 1-2 hours depending on phylum of fruit candy for jellification. Then remove cylinders from a plate, turn so that the inferior establishment of the cylinder has appeared from above and put in the device for definition fastnesses (device Valenta). Before definition from fruit candy samples adjoins the metal form-cylinder, having untied a thread and slightly having moved apart plane edges.
Device Valenta represents vertical the mobile rod reinforced in a support. On the inferior end of a rod there is a metal nozzle-ball. On top end the calyx is reinforced. The inferior end of a rod with a nozzle alights on a surface of the sample in its centre, is simultaneous in the top calyx fill a fraction. The last should be effected with a speed about 10-12 g a minute until the nozzle pressing on a sample will not effect its breakage.
Fastness of fruit candy jell is expressed in grammas of the load necessary for its breakage. Total weight of a load is thus considered: a fraction, a rod with a nozzle and a calyx. Centre fastness – 200g.
Moisture determination
Humidity defines drying on device ВЧМ, at temperature 160-165 °С, in flow of 3 minutes. Preliminarily having weighed empty weighing bottles, and weighing bottles with a shot of 5. Then cool in the exsiccate, 20 minutes and weigh again. Define a difference between weightings’ before drying. Data register in laboratory magazine.
Acidity test
Actual acidity (рН). Measure by a potentiometer method by means of a glass electrode. (See the instruction to a potentiometer рН-340, ЛПУ-01 or other mark).
Titrated acidity. Define titration with the indicator the same as titrate acidity of mashed potatoes.
Reducing sugar. Define a method based on restoration of an alkaline solution of copper. This method use for definition of reducing sugars in caramel. Unlike the described procedure of definition of reducing sugars in fondant sweets sedimentation of non-sugars from fruit candy solution (pulp, pectin, etc.) is made.
Organoleptic estimation
Taste, odor and color - obviously expressed, characteristic for each data
fruit candy names, without an off-taste and odor.
Kind in a break - for fruit candy a break pure, homogeneous;
are supposed individual small nonrigid impregnations; for
jelly on agar-agar - a transparent layer and a vitreous break;
for fruit candy on pectin, acaroids and agar-agar from a furcellaria
is supposed semi-transparent, slightly rather turbid layer,
not glassy in a break.
Consistence - for fruit pan-gelatinous, giving in to kerfs by a knife, for jelly on pectin.
The form and outward - correct, with clear drawing, accurate contours.
The crust and outer surface state - for fruit pan - fine-crystalline, elastic, with gloss, is supposed slightly matte crust, for jelly - the surface is evenly sprinkled by a fine-crystalline granulated sugar.
Table 4-The record form
| The name | Fruit candy | |
| fruit | jelly | |
| Humidity of an applesauce, % | ||
| Acidity of an applesauce, % | ||
| Temperature of fruit candy mass in the end of cooking, °С | ||
| Duration of cooking, mines | ||
| Humidity of fruit candy mass, % | ||
| Duration jell formation, mines (or сек) | ||
| Actual acidity (рН) | ||
| Titrated acidity, citric acid, % | ||
| The maintenance of reducing sugars, % | ||
| Organoleptic estimation of fruit candy: Taste | ||
| Odor | ||
| Color | ||
| Consistence | ||
| The form and outward | ||
| Kind in a break | ||
| Crust and outer surface state |
Theoretical part
Chocolate are the confectionery products received from an is thin-crushed chocolate paste on the basis of products of processing of a cacao beans (cocoa mass, cacao butters, cocoa powder) with sugar or its replaces with addition or without addition of other kinds of raw materials, food supplements and-or aromatic substances. At chocolate production utilization of replacement fats (including cacao butter equivalents), except for a stuffing is not supposed.
The basic recipe of chocolate components are cocoa-products (cocoa mass, cacao butter), received of a cacao beans. At extraction from cacao butter cocoa mass there is a press cake. From a cocoa press cake develop cocoa powder.
As additions in a chocolate industry use milk powder, nuts, a wafer chip, coffee, candied fruits, the raisin, the blown up grains of rice, corn-flakes, etc.
Depending on the recipe the maintenance in chocolate of cocoa-products is regulated. So, cocoa mass, cacao butter and cocoa powder should be in a chocolate paste without additions and with fine-grained additions not less than 25 %, with large additions. - not less than 22 %. Various gustative and aromatic substances are entered into a chocolate paste or in a stuffing. Composition of chocolate includes 55-63 % of sugar, 30-38 % of fat (the basic fat - cacao butter), to 4 % of protect substances, 0,6 % of Theo bromine and caffeine, etc.
Depending on the recipe and a way of processing chocolate is subdivided into following kinds: ordinary without additions and with additions; dessert without additions and with additions; porous without additions and with additions; with stuffing; white chocolate, diabetic chocolate.
Stuffing can be fruit, nut, chocolate, fruit-marmalade, chocolate-cream, fondant chocolate, etc. Quantity of stuffing, as a rule, makes 20 - 35 %, but no more than 50 % from sheathe weights of a chocolate confectioner. As additions in a chocolate industry use milk powder, nuts, a wafer chip, coffee, candied fruits, the raisin, the blown up grains of rice, corn-flakes, etc.
The aerated chocolate unlike other kinds of a bar chocolate has greater volume and a characteristic cellular structure. An aerated chocolate version is air chocolate. Porosity of its framework is reached by saturation of a chocolate paste by a carbon dioxide.
The basic recipe chocolate components are cocoa-products (cocoa mass, cacao butter), received of a cacao beans. At extraction from cacao butter cocoa mass there is a press cake. From a cocoa press cake develop cocoa powder.
Chocolate let out piece in the form of tiles, medals, and candy sticks, the various figures, packed in the form of mixes or sets or one name and to drug rooms. In diabetic chocolate instead of granulated sugar add koenlinite, a sorbet, mannite, a laevulose.
Materials and the equipment
- Cocoa mass, a powdered sugar, milk powder, a kernel paste, coffee;
- A mixing pipette or a mix.
Method of performance
Preparation recipe of chocolate paste admixturesis effected under the working recipe and consists in mixing together warmingcocoa mass, parts recipe quantities of cacao butter, a powdered sugar and all additives (milk powder, a kernel paste, coffee, etc.). The weight fraction of cocoa-products in chocolate under the recipe should compound not less than 25 %, the general maintenance of fat - 24-30 % depending on particle fineness and composition recipe components. Mixing together effect in batch mixers (mixes, mixing pipettes) flow 5 - 25 minutes.
As a result of mixing together the homogeneous mass with uniform allocation of solids in cacao butter is received. Simultaneously there is an interaction of solid parts with formation coagulation frames that is a gelatin process.
Recipes on chocolate contain in the receiving tank of the unified formulas «Recipes on chocolate and cocoa powder», the receiving tank «Recipes and technological instructions on a candy manufacture. Recipes are numbered, after the product name the short characteristic is yielded. For example:
The recipe of chocolate.
Fondant chocolate without additions. Is issued turned in the form of tiles in mass no more than 150
Table 5
| The name of raw materials | Weight fraction of dry matters, % | The raw materials expense, kg | |||
| On 1 т a semi product | On 1 т finished goods (without turning stuffs) | ||||
| In nature | In dry matters | In nature | In dry matters | ||
| Powdered sugar | 99,85 | 504,36 | 503,60 | 507,5 | 506,7 |
| Cocoa mass | 97,8 | 331,40 | 324,11 | 333,4 | 326,1 |
| Cocoa - an oil | 100,0 | 171,35 | 171,35 | 172,4 | 172,4 |
| Soybean phosphate concentrate | 99,0 | 4,0 | 3,96 | 4,0 | 4,0 |
| Vanilla essence | ___ | 0,6 | ___ | 0,6 | ___ |
| Total | - | 1011,71 | 1003,02 | 1017,9 | 1009,2 |
| Yield | 99,3 | 1000,0 | 993,0 | 1000,0 | 993,0 |
| Fat of 35 % |
Feature of the recipe on chocolate consists that in it the expense of a commodity cacao beans as the basic raw materials is not yielded, and only the expense of the cocoa-products produced from a cacao beans on effecting. In the recipe is resulted the powdered sugar interrelation, cocoa mass and cacao butters which define taste of chocolate (bitter or sweet). In each recipe losses are considered.
Theoretical part
Confectionery goods are called the food articles, whose large part consists of sugar or another sweet substance (honey, xylite, sorbite), treacle, fruits, berries, milk, butter, cocoa- beans, it is nut and so forth Confectionery goods are subdivided into two groups: sugar and meal. The sugar confectionery articles include: caramel, candy, chocolate, fruit and berry articles (jam, jam, jam, jelly, candied fruits, jelly-candy, zephyr, and pastille), halva, iris, lozenge, eastern sweetness’s. The meal confectionery articles include: pastry, cakes, wafer, pastry, cakes, meat loaves, rum rams, and eastern meal sweetness’s.
Control questions
1. Give organoleptic estimation of the fruit jellies.
2. What factor is characterized fastness of fruit jellies?
3. What products are main recipe components of chocolate?
4. What additives are used at fabrication of chocolate?
5. Which the classification of confectionery articles?
6. What requirements are imposed on the quality of caramel?
7. What defects are observed in the caramel?
8. Give requirements for the quality of chocolate.
9. What defects do have candies?
Laboratory work #10
Theoretical part
Flour confectionery articles. The meal confectionery articles include pastry sugar, protracted and rich, pancake coils biscuits and cracker (dry pastry), cakes, wafer, pastry, cakes, cakes, meat loaf and rum rams.
Pastryis the most common type of meal confectionery articles.
Requirements for the quality of pastry. Organoleptic indices: the form of pastry, figure, surface, color, taste and smell. In the fracture the pastry must be well baked through, evenly porous. The content of sugar and fat, and also humidity and dimensions of pastry depend on its form and type. Defects of the pastry: the pastry deformed, slightly burnt, half-baked, with the tracks of nepromesa, with the strangers by taste and the smell. The pastry with the defects is not allowed in sale. The pastry, which contains is more than 5% cracked copies, they carry to the scrap.
Cakes - these are meal confectionery articles to diverse form. On the size and the form cakes divide into small (round, oval and figured), long loaves (rectangular) and honey cakes (rectangular).
The requirements for the quality of cakes. Organoleptic indices: form, surface, color, taste and smell. Consistency: cakes must be soft, well baked through, not sticky, without the temper, without the not intervene clusters. Porosity must be uniform, without the voids; cakes with the filling can be less porous in the places, which border to the filling. Humidity of cakes 14,5%, and cakes with the filling also of honey cakes - 16%.
Wafers - light porous meal confectionery articles in the form of thin sheets or figurines with the cellular or corrugated surface.
Requirements for the quality of wafers. Organoleptic indices: form, color (they are not allowed spot and burnt, taste smelled fillings they must have uniform mass, without the grains and the clusters (cream and nut). The consistency of fillings must be easily melting, tender, and oily. The humidity of wafers with the filling of fruit-jelly must be from 4, 4- 8,4%, with the fruit filling to 15,3%, with praline filling 0,6- 2,2%.
Pastry and cakes are the high-calorie meal confectionery articles, which contain a large quantity of fat, sugar, the eggs mélange or only of sugar and eggs, diverse form, also, with the beautiful external finishing.
Requirements for the quality of pastry and cakes. Organoleptic indices: form, finishing, taste. Dough must be well baked through, not slightly burnt, without the tracks of nepromesa, the puff-pastry articles have to be of temper.
To give classification, characteristic of assortment and requirement for the quality of the meal confectionery articles: pastry, cakes, wafers, cakes and pastry in the form of table.
Control questions
1. Which the classification of meal confectionery articles?
2. You will transfer the defects of pastry and cakes.
3. What requirements are imposed on the quality of meal confectionery articles?
4. What requirements are imposed on the quality of cakes and pastry?
Laboratory work # 11
Kvass for hash and bread kvass for hot shops, prepared by fermenting an opaque have brown drinks. They have a sweet-sour taste and aroma of rye bread. Kvass for hash has a more sour taste. Kvass good quench thirst, contain alcohol, carbon dioxide, lactic and acetic acids, nitrogenous substances, sugar, dextrin, minerals, vitamins B and D.
Produced varieties kvass must meet the requirements listed in Table 10
Work progress
Table 11
| The index | Number of tubes | ||||||||
| Number of stock solution of aspartame has been added to the tubes, cm3 | 2,5 | 3,5 | 4,5 | 5,5 | - | ||||
| Amount of distilled water added to tubes cm3 | 7,5 | 6,5 | 5,5 | 4,5 | |||||
| The concentration of aspartame in 100 cm3 of the working solution, mg | - |
The optical density of solutions of the samples is determined against a zero sample on a spectrophotometer at an average wavelength of 570 nm or at FEK at a wavelength of 582 nm (filter number 6) in a cell thickness of 10 mm.
By optical density on the plotted graph are the concentration of aspartame in a dilute solution (Cp), and the true concentration of aspartame (C) is calculated by the equation
C= Cp • K,
where K - the degree of a dilute solution. In our example, K = 5.
By this method it can determine the concentration of aspartame in the range of 20-50 mg per 100 cm3 of the drink.
Control questions
Laboratory work # 12
Assessment of the quality of beer
Objective: To develop skills in the principles of the classification and the range of beers in the establishment of defects in the preparation of samples for the determination of quality in examination quality.
Materials and equipment: Analytical balance with a maximum weighing limit of 200 g; bath water; pycnometer flask at 75, 100 and 1000 ml separatory funnel of 100 ml and 1000, the centrifuge, pipettes, filter paper, desiccator oven, potassium dichromate; sulfuric acid; rectified ethyl alcohol; chromic mixture, 1.2 g of potassium dichromate was dissolved in 100 cm3 of sulfuric acid, chloroform, anhydrous sodium sulphate.
Theoretical part
The final stage of the technological control of the production of beer is the assessment of the quality of the finished product, which is carried out by organoleptic and physico-chemical parameters.
The main indicators of quality of beer as a beverage are transparency, color, taste, aroma, hop bitterness, foaming. All these properties are determined in the process of beer tasting.
By the physico-chemical parameters of beer include mass fraction of solids in the Wort, the mass fraction of the actual alcohol and extract, acidity, color, mass fraction of carbon dioxide (for bottled beer), stability of beer, while secondary fermentation. The taste of beer referred to as organoleptic characteristics. The bitter taste of beer caused mainly by bitter substances of hops, as well as tannins as hops and malt and unmalted shell grains. Bitter substances of hops presented soft and hard resins. Soft resins - is α-acid (humulone), β-acid (lupulon), soft α- and β-resin, γ-acid (gumulion), σ-acid (gulupon) and β-fraction (the amount of β-acids and soft resins). Solid resin is separated into γ- and σ-resin.
Among the bitter substances is dominated by α-acid. Upon drying and storage of hops it oxidizes and polymerizes to form α-soft resin and a deeper oxidation - solid resin. When boiling wortα-acid is converted into iso-α-acids having more bitterness and solubility in water.
As a part of β-acids prevails lupulon which when boiled wort remains in the hop pellet. When oxidation is converted into β-resin soluble in the wort and beer.
α-acid iso-α-acid
R: isobutyl (humulone); isopropyl (kogumulon); sec-butyl (adgumulon)
The solubility of the soft resin in the wort is higher than the acids from which they are formed.
Solid resin formed by the oxidation of acids have little bitterness, only σ-solid resin has a coarse and bitter soluble in wort and beer.
In the process of producing beer portion of bitter substances is lost due to adsorption on the yeast and the ascent to the CO2 bubbles. Only 20-40% of the original bitter substances present in the beer.
Thinner bitter compounds in beer as well as in the wort, is a chloroform, and it should be noted that out of the whole complex of bitter substances α-bitter acid (humulone) at a pH of beer has the highest solubility and many times superior in this regard β-bitter acid (lupulon).
Experimental part
Determination of the bitter substances in beer. Beer previously freed of the main mass of the carbon dioxide agitation and filtration. What beer in an amount of 250-400 ml was poured into a flask of about 1 dm3 and stirred at room temperature its closed throat and opening the receptacle palm vessel from time to time until the stop feeling of pressure from within. Opaque beer should be filtered.
400 ml (V) of beer is placed in a glass flask stoppered with a capacity of 750 - 1000 ml, acidified with 5 ml of dilute sulfuric acid and 50 ml of chloroform. The flask was placed in "vibrating conveyor" and the contents are vigorously shaken for 30 minutes, after which it was poured into a separatory funnel and allowed to 500-750 ml within a few hours peel aqueous portion of chloroform. The chloroform resultant emulsion to break centrifuged for 10 - 15 minutes at 2000 - 3000 rev / min. The aqueous portion in centrifuge tubes carefully decanted and the clear chloroform extract sedimented at the bottom of the tubes, suction filtered pipette tip thrusting it through a layer of light-gray mass accumulated over chloroform and collect it in a separatory funnel for 80 - 100 ml.
After 5-10 minutes of settling the chloroform layer was collected in a flask with a capacity of 100 - 150 ml with ground glass stopper. In the flask was placed beforehand about 15 g of anhydrous sodium sulfate for drying the chloroform extract. Content flasks for 5 - 10 minutes of stirring, after which the chloroform extract was filtered through a small filter paper.
30 ml (V1) of the filtrate pipetted into preweighed round flask with a capacity of about 75 ml. Chloroform was removed under vacuum on a boiling water bath until its complete removal. Flask with the residue is kept 1 hour in a desiccator (preferably in a vacuum desiccator with a dehydrating agent) and weighed. Allowed without vacuum distillation of chloroform on a water bath at 65-70 ° C and the residue in a round bottom flask can be dried in an oven at 70 ° C for 1 hour. The content of bitter substances (X) in grams per 1 dm3 of beer is given by:
where: m - weight of residue in the flask after the distillation of chloroform g;
V - volume of beer taken for analysis, in ml;
V1- filtrate volume for analysis in ml.
Normally in beer contains about 0,03-0,09 g of bitter substances in 1 dm3.
Determination of relative density: pycnometer carefully washed chromate solution and distilled water and dried to constant weight and weighed up to the fourth decimal place. Double-distilled water it is filled with a temperature 19-21 ° C higher bit tags stoppered and immersed waterbath with temperature (20,0 ± 0,2) ° C so that the water level in the bath was a little above the water level in the pycnometer. After 20-30 minutes, without removing the pycnometer from the bath at a temperature of 20 ° C, determine the level of water in it so that the bottom edge of the meniscus was level with the mark. Excess water is collected in the pycnometer strip of filter paper. The inner surface of the neck above the pycnometer label carefully wiped with filter paper.
Stoppered pycnometer, is removed from the bath, wipe dry with a dry towel, and weighed up to the fourth decimal place.
Filling the pycnometer with water, the installation of the water level in it and weighing spend 3-4 times as long as the difference in weight is not more 0,0030g. Calculate the arithmetic mean value of the mass of the pycnometer with water.
Then pycnometer freed from water, rinsed 2-3 times with the test solution (solution distillate) and filled pycnometer just above the label.
Tempering, the installation level of the solution and weighing the pycnometer method described above is carried out at a temperature of 20 ° C. Spend at least two parallel determinations.
The relative density of the solution of the distillate (d) is calculated by the formula:
where m - mass of the pycnometer with the solution of the distillate, g;
m1- mass of the pycnometer, g;
m2- mass of the pycnometer with distilled water, the
The weight proportion of alcohol in a percentage depending on the relative density of the distillate is determined by solution Table. 1 of Schedule 2.
If the weight of distillate sample differs from the mass of beer, the value obtained by Table 1 is multiplied by the correction coefficient (K) computed by formula:
where m4 - weight distillate g; m5 - lotsofbeer, g
Control questions
Laboratory work # 13
Theoretically part
Emulsion liqueurs - it's milk, butter, egg and other liquors with fillers, flavorings, and without them. are a relatively new group of beverages, which are in high demand because of an unusual and pleasant mild flavor, low strength and attractive appearance. Currently, the Kazakh consumer market in a wide assortment of cream liqueurs mostly foreign manufacturers. Production of cream liqueur is a complex multistage process with the use of expensive equipment, resulting in increased production costs. In terms of rigidity of competition, expensive technology reduces the interest of domestic producers in the production of such beverages. Liqueurs are classified by the nature of the filler. The main types of the latter are herbs, fruits, nuts, coffee and eggs and cream.
Necessary equipment and materials: Natural samples of liquor-vodka beverages. Standards of liquor-vodka beverages. Catalogues "Liquor-vodka beverages."
Pipette with a capacity of 10, 5, 1, 20, 25 cm3. Test tubes ПП 20- КШ 10/19. Liquid Glass Thermometers. Glasses for tasting. Measuring flasks with graduated neck guilt. Flasks 2-500-2; 2-250-2; П-500, П-1000, 2-200-2, КН-100, КН-200, КН-250. Stopwatch. Areometer for spirit of АСП-1 or АСП-2. Cylinders 1-50, 1-100, 1-500. Stove. Glass tubes. Drop catcher. Bath water. Glass rods. Scales. Desiccator. Dropper. Funnel. Burettes capacity 25 cm3. Porcelain plate. Potentiometer. Laboratory refractometer. Glass refrigerator.
Hydrochloric acid, solution of sodium hydroxide (concentration 1 and 0.1 mol/dm3), a solution of phenolphthalein (1%), distilled water, a solution of Fehling I and II; solution of blue bromothymol (0.05 %).
Work progress
Determining the completeness of filling. The product of the bottle caution pricks on the wall is poured into a clean, dry flask or a flask with graduated neck. The volume of the product drain test after discharge and holding a bottle for 0.5 min over a funnel placed in a flask.
Underfilling quantify the introduction of a measuring flask to the mark of an additional quantity of product pipette with a scale division of 0.05 cm3.
Overflow quantify the removal of excess product from the measuring flask to the mark with a pipette with a scale division of 0.05 cm3.
Determine the completeness of filling at a temperature of 20 ± 0,5°C. At a different temperature into account a correction for temperature ГОСТ Р 51135).
Determination of the fortress hydrometer. The method is based on the measurement of the volume fraction ethyl alcohol hydrometer in the distillyate obtained after a preliminary distillation of alcohol from beverage.
Liquor-vodka beverages are poured up to the mark in a volumetric flask with a capacity of 250-500 cm3 at 20°C, carried of the volumetric flask to the distillation flask 500-1000 cm3. The remains of the product wash off with distilled water from volumetric flask in the distillation flask in such a way that the dimension of distilled water did not exceed 60-100 cm3.
The distillation flask connected to a vertical or direct-flow refrigerators by glass tube or drop catcher and the contents is distilled.
Volumetric flask which measure the test product is a receiving flask for the. In the flask prior before the distillation, pour 10-15 cm3 of distilled water and immersed the flask in a bath with cold water. The narrow end of a glass tube of refrigerator is placed in water at receiving flask. After filling in the receiving flask to about half of its volume the distillation water continues without the gate.
After receiving flask filled with a 3/4 of volume, the distillation is stopped. The flask with the distillate topped up with distilled water just below the label and stand 20-30 min at 20 ° C in a water bath.
Then contents of receiving flask adjusted to the mark with distillate water. Vigorously mixed, poured into a dry glass cylinder for areometer to determine the amount of alcohol stake hydrometer for alcohol or metal alcoholometer.
Determination of mass concentration of total extract by refractometric method. The method is based on definition of mass concentration of dry matter on a scale refractometer at 20° C.
The contents of flask remaining after the distillation of alcohol, washed with distilled water without loss to the flask with a capacity of 200-500 cm3 and at temperature of 20° C lead with distillate water to the mark. The solution in the flask carefully stir and bring a drop of test solution at the bottom prism of refractometer with fused glass stick. The upper part of prism is lowered, tightly applied to the lower fixed part of prism and note readouts on scale of refractometer.
If the refractometer readouts noted at a temperature different from 20°C, it is necessary to introduce an amendment (ГОСТ 51135).
The discrepancy between two parallel determinations should not exceed 0.1%.
Determination of mass concentration of sugar by method of direct titration. The method is based on titration defined quantity of Fehling solution (oxidizer) of known concentration of a solution containing sugar, until the recovery of copper oxide (2 +) in the copper protoxide (1 +).
The method used for quality control of products, and also in event of disagreement in the assessment of quality. Drawbacks of method ± 1,8%.
The test product was diluted with distilled water (see Table. 3, ГОСТ 51135).
Measure with a pipette a 25 cm3 of test product diluted in a volumetric flask with a capacity of 100 cm3. To a solution flow 25 cm3 of distilled water, and 3cm3 of hydrochloric acid (density 1.90 g/cm3). The contents of flask stirred and heated on a water bath for 5 min at 67-70°C with frequent stirring.
Then solution rapidly cooled and neutralized with sodium hydroxide of concentration 1mol/dm3 in presence of phenolphthalein. After inversion and neutralization the contents of the flask at 20°C lead with distillated water to mark and mix thoroughly.
In a conical flask with a capacity of 150-200 cm3 measure off 10 cm3 of solution Fehling I and II, and heated to boiling, add 2-3 drops of methylene blue, and boiling without stopping, from a burette with a levigated crane gently and slowly poured into the flask invert sugar antill disappearance of blue color. Then add 2-5 drops of methylene blue solution (1 percent) to mixture and boiling without stopping, continued to flow of invert sugar solution dropwise until the color of boiling mixture goes into the red or orange.
The duration of liquid boiling in flask during the titration should not exceed 3 minutes, then from the mark as consumed in the titration of the sugar solution, which is considered indicative. Then re-titration is carried out, but to a mixture of Fehling solutions I and II were added to the flask heated by 0.5-1.0 cm3 of invert sugar less than expend to the first titration.
The mixture in a flask boiled for 2 minutes, continuing boiling, add 3-5 drops of methylene blue solution. Then flow 2-3 drops of invert sugars from a burette, giving a mixture after each addition simmer 2-3 seconds until blue colouring disappears in a flask and the mixture does not take a red or orange colour. After that note the quantity of solution expended for titration.
Mass concentration of sugar (Xsugar) in recalculation on sucrose in grams per 100 cm3 of test solution is calculated by the formula
Хsugar= K 100 n ·0,95 ,
V
where K - correction coefficient to the titre of Fehling solution I and II;
100 - volume of analyzed product, after inversion, cm3;
n - the coefficient of dilution of analyzed beverage;
0.95 – recalculation coefficient of invert sugar in total sugar;
V - total volume of test solution expended to titration cm3.
The final result of test should be the arithmetical average of the results two parallel definitions which allowed differences between them should not exceed 5%.
Determination of mass concentration of acid. Mass acid concentration of liquor- vodka products determined by acidimetric method and method of electrometrically titration.
The acidimetric titration method is based on titration of test product with sodium hydroxide solution until a neutral reaction determining with indicator.
Measure with a pipette 10 cm3 of test product is transferred into a conical flask with a capacity of 100-250 cm3, added boiled distilled water: for the light-coloured products - 25-30cm3, and for dark-coloured - 100 cm3.
The contents of flask stirred with fused glass stick and titrated with sodium hydroxide concentration 0.1 mol/dm3 in the presence of an indicator, bromothymol blue or phenolphthalein. The end of titration determine by appearance of a light green colour in the drop test on a porcelain plate with using of bromothymol blue and pink - by using phenolphthalein.
The mass concentration of acid (C) in grams of citric acid in 100 cm3 (g/cm3) of researching product, calculated by the formula
С= VK ·100 · 0,0064 = 0,064VK,
where V - volume of solution sodium hydroxide expended in the titration, cm3;
0.0064 - mass of citric acid conformed to 1 cm3 of sodium hydroxide concentration of 0.1 mol/dm3;
10 - volume of test product, cm3;
K - correction coefficient to the titre of solution sodium hydroxide concentration of 0.1 mol/dm3.
The final result of test should be the arithmetical average of the results two parallel definitions which allowed differences between them should not exceed 5%.
Method of electrometric titration is based on titration of test product with sodium hydroxide solution until a neutral reaction determining with potentiometer.
In a glass with a capacity of 100cm3 measure 10 cm3 of test products, added 50 cm3 of distilled water, stirred and heated to boiling and cooled to room temperature. The solution titrated with sodium hydroxide concentration of 0.1 mol/dm3 in small portions, and then drop by drop. After each addition of solution the liquid in flask stirred and observed the readouts of potentiometer. The titration finished at pH 7.0.
Mass concentration of acid is calculated at indicated titration by quantity of expended sodium hydroxide solution, subsequent recalculation of citric acid in grams per 100 cm3.
The results of assessment physical-chemical parameters of quality liquor-vodka beverages draw into a table 12.
Control questions
1. Determining the completeness of filling.
2. Determination of mass concentration of total extract by refractometric method.
3. Determination of mass concentration of sugar by method of direct titration.
4. Determination of mass concentration of acid.
5. Method of electrometric titration
Work progress
Objective: To carry out identification examination of starch and food iodized salt using measurement and test methods. Means of education:
1. GOST 7699-78. Potato starch. Technical conditions.
2. GOST R 51985-02. Corn starch. General specifications.
3. GOST R 51574-2000. "Food salt of salt".
4. Samples in packages of iodized table salt, potato and corn starch.
Equipment and materials: drying cabinet, microscope, stopwatch (hours), thermometer, laboratory scales, conical flasks and glasses with a capacity of 50, 100 ml, test tubes, pipettes for 5 and 10 ml, spatula.
Reagents: 1% solution of sodium sulphide, zinc metal, nitric silver (crist.), Diphenylamine, concentrated sulfuric acid, tannin, starch solution, ethyl alcohol (50 ml).
Situational challenge. Conduct species identification of starch samples by microscopic method (samples without marking are given by the teacher).
Detection of alkaloids
To 5 ml of the solution of table salt add 5 drops of a solution of tannin. The presence of turbidity or white precipitate indicates the presence of alkaloids (not allowed).
Literature
1. Тимофеева В.А. Товароведение продовольственных товаров: учебник.- Изд.8-е, доп. И перераб.-Ростов н/Д: Фениекс, 2008.- 475 с.
2. Микулович Л.С.