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Amino acid speed What it is? Limiting amino acids

Laboratory work No. 10

CALCULATION OF BIOLOGICAL VALUE AND

FATTY ACID COMPOSITION OF PRODUCTS

FOR BABY FOOD

Goal of the work. Master calculation methods for determining the mass fraction of protein based on its amino acid composition and the mass fraction of fat based on its fatty acid composition.

Brief theoretical information. There are no products in nature that contain all the components necessary for humans, therefore only a combination of different products best provides the body with the delivery of the necessary physiologically active components with food. The results of scientific research by leading domestic scientists formulate principles and formalized methods for designing rational food recipes with a given set of nutritional value indicators.

Academician of the Russian Academy of Agricultural Sciences N.N. Lipatov (Jr.) proposed an approach to the design of multicomponent products that takes into account the specifics of the individual characteristics of the organism. Adhering to the basic concept of rational nutrition, in his opinion, the task of optimizing recipes is to select such components and determine their ratios that ensure that the mass fractions of nutrients are as close as possible to personalized standards. We proceed from the assumption that all types of mechanical processing of raw materials associated with the preparation of recipe mixtures, giving individual components the required dispersion or the necessary rheological properties, do not violate the principle of superposition in relation to the biologically important nutrients of the original ingredients. Then calculated information is obtained on the mass fractions of proteins, lipids, carbohydrates, minerals, and vitamins. To design and evaluate the largest possible number of combinations of initial components when developing recipes for new multicomponent food products, a computer-aided design system has been created that allows the use of a data bank on the composition of components.

The development of products that meet specified requirements is to ensure a balanced chemical composition and satisfactory consumer characteristics.

Protein substances make up a significant part of living organisms. They are endowed with a number of specific functions, therefore they are indispensable components of the human diet.

Substances that are not synthesized in the body, but are absolutely necessary for it, are called irreplaceable or essential. Substances that are easily formed and also necessary for the body in certain quantities are called non-essential.

A person needs both the total amount of protein and a certain amount of essential amino acids. Eight of the 20 amino acids (valine, leucine, isoleucine, threonine, methionine, lysine, phenylalanine and tryptophan) are essential, i.e. they are not synthesized in the human body and must be supplied with food. Histidine and arginine are essential components for a young, growing organism.

The absence of a complete set of essential amino acids in the body leads to a negative nitrogen balance, disruption of the rate of protein synthesis, growth arrest, and disruption of the functioning of organs and systems. If there is a deficiency of at least one of the essential amino acids in the body, there is an overconsumption of protein to fully meet the physiological needs for essential amino acids. Excess amino acids will be ineffectively spent for energy purposes or converted into storage substances (fat, glycogen).

The presence of a complete set of essential amino acids in sufficient quantity and in a certain ratio with non-essential amino acids is characterized by the concept of “quality” of food protein. Protein quality is an integral part of determining the nutritional value of foods and is assessed using biological and chemical methods. Biological methods determine biological value (BC), net protein utilization (NPL) and protein efficiency coefficient (PEC), and chemical methods determine amino acid rate.

Biological methods involve the use of experiments on young animals with the inclusion of the studied protein or food products with it in their diet.

Biological value of protein (BC). The indicator reflects the proportion of nitrogen retention in the body from the total amount of absorbed nitrogen. The control group of animals received a protein-free diet (N cont), the experimental group received the test protein. In both groups, the amount of nitrogen excreted in feces (N k), urine (N m) and consumed with food (N int) is determined.

BC = N consum - N k – N m – N cont, (27)

With a BC of 70% or more, protein is able to ensure the growth of the body.

Net Protein Utilization (NPR). This indicator is calculated by multiplying the BC by the protein digestibility coefficient.

CHUB = BC K lane, (28)

The digestibility rate varies from 65% for some plant proteins to 97% for egg whites.

Protein efficiency factor (PER) reflects the increase in body weight per 1 g of protein consumed. It is determined at 9% of the studied protein in calorie content in the animal diet. The rat diet with casein, whose EBC is 2.5, is used as a control diet.

Protein amino acid score (AAS). The calculation of the amino acid score is based on comparing the amino acid composition of food protein with the amino acid composition of a reference (“ideal”) protein. A reference protein reflects the composition of a hypothetical protein of high nutritional value that ideally satisfies the body's physiological need for essential amino acids. The amino acid composition of such a protein was proposed by the FAO/WHO committee in 1985 and shows the content of each of the essential amino acids in 1 g of protein (Table 25).

Table 25

Amino acid scale and daily requirement for

essential amino acids at different ages

Amino acids

Reference protein, mg/kg protein

Teenagers

Adults

mg/kg body weight per day

Isoleucine

Methionine + cysteine

Phenylalanine + tyrosine

Tryptophan

Speed is expressed as a dimensionless quantity or as a percentage:

The amino acid whose acid has the smallest value is called limiting. In products with low biological value, there may be several limiting amino acids with a rate of less than 100%. In this case, we are talking about the first, second and third limiting amino acids. Lysine, threonine, tryptophan and sulfur-containing amino acids (methionine, cysteine) often act as limiting amino acids.

The proteins of cereal crops (wheat, rye, oats, corn) are limited in lysine, threonine, and some legumes are limited in methionine and cysteine. The closest to the “ideal” protein are the proteins of eggs, meat, and milk.

The biological value of proteins during thermal, mechanical, ultrasonic or other types of processing, as well as transportation and storage, can be reduced, especially due to the interaction of essential amino acids, often lysine, with other components. In this case, compounds that are inaccessible to digestion in the human body are formed. At the same time, the BC and AC of proteins can be increased by composing mixtures of products or adding missing and labile essential amino acids. For example, a combination of wheat and soybean proteins at certain ratios provides a complete set of amino acids.

Amino acid rate difference coefficient (RAS, %) shows the excess amount of NAC that is not used for plastic needs, and it is calculated as the average amount of excess AAC of an essential amino acid relative to the lowest rate of a particular acid:

where ΔPAC is the difference in amino acid score of an amino acid, %;

n is the amount of NAC;

ΔAKS i – excess score of the i-th amino acid, % (ΔAKS i = AKS i – 100, AKS i – amino acid score for the i-th essential acid);

AKS min – rate of limiting acid, %.

Recycling ratei-NAK (K i ) – a characteristic reflecting the balance of NAC in relation to the reference protein. Calculated using the formula:

, (31)

Rationality coefficient of amino acid composition (R With ) reflects the balance of the NAC relative to the standard and is calculated using the formula:

, (32)

where K i is the utilitarian coefficient of i-NAK;

A i – mass fraction of the i-th amino acid in g of reference protein, mg/g.

To assess the quality of fats by fatty acid composition, the Institute of Nutrition of the Russian Academy of Medical Sciences and VNIIMS proposed, by analogy with ideal protein, to introduce the concept of “hypothetically ideal fat,” which provides for certain relationships between individual groups and representatives of fatty acids. According to this model, a “hypothetically ideal fat” should contain (in relative parts): unsaturated fatty acids - from 0.38 to 0.47; saturated fatty acids - from 0.53 to 0.62; oleic acid - from 0.38 to 0.32; linoleic acid - from 0.07 to 0.12; linolenic acid - from 0.005 to 0.01; low molecular weight saturated fatty acids - from 0.1 to 0.12; trans isomers - no more than 0.16. The ratio of the content of unsaturated and saturated fatty acids in such fat should be in the range from 0.6 to 0.9; linoleic and linolenic acids - from 7 to 40; linoleic and oleic acids - from 0.25 to 0.4; oleic with linoleic and pentadecyl with stearic acids - from 0.9 to 1.4.

Organization, order of execution and execution of work. Having received a control task from the teacher, students calculate the amino acid score of proteins and the fatty acid composition of various food products, their mixtures, compositions or objects that have been subjected to various methods and factors of technological processing or storage conditions.

Amino acid speed Example. According to the amino acid composition, calculate the amino acid score of a product for baby food of the following composition (in%): beef - 25, liver - 40, vegetable oil - 2, wheat flour - 3, table salt - 0.3, drinking water (the rest up to 100) .

Table 26

Mass fraction of protein and content of essential amino acids in products

Food product

Essential amino acids, mg/100 g

Beef

vegetable

wheat

From the data given in table. 21, it is clear that 100 g of beef contains 21.6 g of protein, 939 mg of isoleucine, 1624 mg of leucine, 1742 mg of lysine, 588 mg of methionine, 310 mg of cysteine, 904 mg of phenylalanine, 800 mg of tyrosine, 875 mg of threonine, 273 mg tryptophan and 1148 mg of valine, therefore, 1 g of beef protein will contain:

mg isoleucine;
mg leucine;
mg lysine;

mg methionine;
mg cysteine;
mg phenylalanine;

mg tyrosine;
mg threonine;
mg tryptophan;

mg valine.

100 g of liver contains 17.9 g of protein, 926 mg of isoleucine, 1594 mg of leucine, 1433 mg of lysine, 438 mg of methionine, 318 mg of cysteine, 928 mg of phenylalanine, 731 mg of tyrosine, 812 mg of threonine, 238 mg of tryptophan and 1247 mg of valine Therefore, 1 g of liver protein will contain:

mg isoleucine;
mg leucine;
mg lysine;

mg methionine;
mg cysteine;
mg phenylalanine;

mg tyrosine;
mg threonine;
mg tryptophan;

mg valine.

100 g of vegetable oil contains 20.7 g of protein, 694 mg of isoleucine, 1343 mg of leucine, 710 mg of lysine, 390 mg of methionine, 396 mg of cysteine, 1049 mg of phenylalanine, 544 mg of tyrosine, 885 mg of threonine, 337 mg of tryptophan and 1071 mg valine, therefore, 1 g of vegetable oil protein will contain:

mg isoleucine;
mg leucine;
mg lysine;

mg methionine;
mg cysteine;
mg phenylalanine;

mg tyrosine;
mg threonine;
mg tryptophan;

mg valine.

100 g of wheat flour contains 10.3 g of protein, 430 mg of isoleucine, 806 mg of leucine, 250 mg of lysine, 153 mg of methionine, 200 mg of cysteine, 500 mg of phenylalanine, 250 mg of tyrosine, 311 mg of threonine, 100 mg of tryptophan and 471 mg of valine, therefore, 1 g of wheat flour protein will contain:

mg isoleucine;
mg leucine;
mg lysine;

mg methionine;
mg cysteine;
mg phenylalanine;

mg tyrosine;
mg threonine;
mg tryptophan;

mg valine.

Therefore, 100 g of a baby food product consisting of 25 g beef, 40 g liver, 2 g vegetable oil, 3 g wheat flour will contain:

mg isoleucine

mg leucine

mg lysine

mg methionine

mg cysteine

mg phenyl-alanine

mg tyrosine

mg threonine

mg tryptophan

mg valine

The “ideal” protein contains 40 mg/g isoleucine, 70 mg/g leucine, 55 mg/g lysine, 35 mg/g methionine with cystine, 60 mg/g phenylalanine with tyrosine, 10 mg/g tryptophan, 40 mg/g threonine, 50 mg/g valine, therefore the ACC, in accordance with formula (27), will be equal to:

% isoleucine;
% leucine;
% lysine;

% methionine with cysteine;

% phenylalanine with tyrosine;

% threonine;
% tryptophan;
% valine.

According to formula (28), ΔPAC will be equal to:

ΔPAC = (84-100)+75 = 59% isoleucine; ΔPAC = (83-100)+75 = 58% leucine;

ΔPAC = (97-100)+75 = 72% lysine;

ΔPAC = (83-100)+75 = 58% methionine with cysteine;

ΔPAC = (101-100)+75 = 76% phenylalanine with tyrosine;

ΔPAC = (75-100)+75 = 50% threonine; ΔPAC = (91-100)+75 = 66% tryptophan;

ΔPAC = (87-100)+75 = 62% valine.

The coefficient of difference in amino acid rates, in accordance with formula (28), is equal to:

The utilization coefficient K i, in accordance with formula (29) is equal to:

K i =
isoleucine; K i =
leucine; K i =
lysine;

K i = methionine with cysteine; K i =
phenylalanine with tyrosine;

K i =
threonine; K i =
tryptophan; K i =
Valina.

The coefficient of rationality of amino acid composition Rc, in accordance with formula (30) is equal to:

R with
isoleucine; R with
leucine; R with
lysine;

R with
methionine with cysteine;

R with
phenylalanine with tyrosine; R with
threonine;

R with
tryptophan; R with
Valina.

The results of calculating amino acid composition indicators, reflecting the quality of food protein, are presented in the form of a table. 27, and indirect conclusions are drawn about the biological value of a particular product.

Table 27

Indicators of amino acid composition of proteins

Amino acid

Limiting AK

reference

researched

Isoleucine

Methionine + cysteine

Phenylalanine + tyrosine

Tryptophan

Fatty acid composition.Example. Calculate the content of polyunsaturated fatty acids in a product of the following composition (in%): poultry meat - 35, rice cereal - 15, pumpkin - 10, vegetable oil - 5, salt - 0.5, sugar - 1.5, tomato puree - 3 , water - the rest up to 100. Compare it with the formula of the “ideal” fat. The ratio of fatty acids in the ideal fat is saturated: monounsaturated: polyunsaturated as 30:60:10, respectively.

The calculation results are summarized in Table 28.

Table 28

Name

Net weight, g

Saturated

Mononene-saturated

Polynene-saturated

Poultry meat

Rice groats

Vegetable oil

Tomato puree

Fatty acids in the product contain:

2,16 + 4,34 + 4,25 = 10,75

Percentage of saturated fatty acids in the product:

Percentage of monounsaturated fatty acids in the product:

Percentage of polyunsaturated fatty acids in the product:

Control questions

What is the biological value of protein?

How is Net Protein Utilization calculated?

What is the Protein Efficiency Ratio?

How is the amino acid score of a protein calculated?

What is a reference protein?

Which amino acid is called limiting?

What does the coefficient of difference in amino acid rates show?

How is the amino acid rate difference coefficient calculated?

What is the recycling rate?

How is the recycling rate calculated?

What is the coefficient of rationality of amino acid composition?

How is the coefficient of rationality of amino acid composition calculated?

What is the “ideal” fat?

Bibliography

Kasyanov G.I. Technology of baby food products: Textbook for students. higher textbook establishments. – M.: Publishing Center “Academy”, 2003. – 224 p.

Production of baby food products: Textbook / L.G. Andreenko, C. Blattny, K. Galachka and others; Ed. P.F. Krasheninina and others - M.: Agropromizdat, 1989. - 336 p.

Prosekov A.Yu., Yuryeva S.Yu., Ostroumova T.L. Technology of baby food products. Dairy products: Textbook. allowance. – 2nd ed., Spanish. / Kemerovo Technological Institute of Food Industry. – Kemerovo; M.: Publishing Association “Russian Universities” - “Kuzbassvuzizdat” - ASTSH”, 2005. – 278 p.

Technology of baby food products: textbook / A.Yu. Prosekov, S.Yu. Yuryeva, A.N. Petrov, A.G. Galstyan. – Kemerovo; M.: Publishing Association "Russian Universities" - "Kuzbassvuzizdat - ASTS", 2006. - 156 p.

Technology of baby food products. Plant-based products: textbook / S.Yu. Yuryeva, A.Yu. Prosekov; KemTIPP. - Kemerovo; M.: IO "Russian Universities" - "Kuzbassvuzizdat - ASTS", 2006. - 136 p.

Ustinova A.V., Timoshenko N.V. Meat products for baby food. – M.: All-Russian Research Institute of Meat Industry, 1997. – 252 p.

Seminar lesson plan

Topic 1. Powdered infant milk products

Characteristics and features of the technology of dry dairy products.

Characteristics of the range of adapted dry milk products.

Features of the technology of milk mixtures “Malyutka” and “Baby”. Storage conditions and periods. Quality requirements.

Characteristics of the assortment and features of the technology of humanized milk powder “Ladushka”. Storage conditions and periods. Quality requirements.

Features of Vitalakt milk powder technology. Storage conditions and periods. Quality requirements.

Characteristics of the assortment and features of the technology of Detolakt dairy products. Storage conditions and periods. Quality requirements.

Features of the technology of dry milk products “Solnyshko” and “Novolakt”. Storage conditions and periods. Quality requirements.

Characteristics of the assortment of non-adapted dry milk products.

Characteristics of the assortment and features of the technology of dry milk porridges. Storage conditions and periods. Quality requirements.

Characteristics of the assortment and technology features of dry milk-vegetable mixtures. Storage conditions and periods. Quality requirements.

Features of the technology of dry acidophilic mixtures. Storage conditions and periods. Quality requirements.

Topic 2. Dietary dairy products

Characteristics of the range of Enpity milk powder mixtures and their composition.

Features of the technology of Enpita milk formulas (protein, fat, low-fat, anti-anemic). Storage conditions and periods. Quality requirements.

Features of the technology of dry acidophilus "Enpita". Storage conditions and periods. Quality requirements.

Characteristics of the range of dry low-lactose milk mixtures and their composition.

Features of the technology of dry low-lactose milk mixtures. Storage conditions and periods. Quality requirements.

Characteristics of the assortment and features of the technology of lactose-free fermented milk mixtures. Storage conditions and periods. Quality requirements.

Features of the technology of dry milk product "Kobomil". Storage conditions and periods. Quality requirements.

Characteristics of the assortment and features of the technology of dry milk dietary porridges. Storage conditions and periods. Quality requirements.

Features of the technology of dry milk product "Inpitan". Storage conditions and periods. Quality requirements.

Characteristics of the range and features of the technology of dry milk biological additives. Storage conditions and periods. Quality requirements.

Topic 3. Canned meat and meat and vegetable products

Characteristics of the range of canned meats and their composition (homogenized, pureed, coarsely ground).

Features of the technology of homogenized canned meat. Storage conditions and periods. Quality requirements.

Features of the technology of canned meat purees. Storage conditions and periods. Quality requirements.

Features of the technology of coarsely ground canned meat. Storage conditions and periods. Quality requirements.

Features of the “Children’s pureed meat puree” technology. Storage conditions and periods. Quality requirements.

Features of the technology of chicken puree soup. Storage conditions and periods. Quality requirements.

Characteristics of the range of canned meat and vegetable products and their composition.

Preparation of canning mass components.

Preparation of emulsion and processing of minced meat raw materials.

Composition and processing of canning mass. Sterilization modes.

Terms and modes of storage of canned meat and vegetables.

Features of the technology of canned food “Children's breakfast meat”. Storage conditions and periods. Quality requirements.

Features of the technology of pate canned puree “Health”. Storage conditions and periods. Quality requirements.

Topic 4. Sausages for baby food

Characteristics of the range of sausage products and their composition.

Characteristics of the stages of the technological process for the production of sausages.

Preparation of raw meat and other components for processing.

Preparation and processing of crushed raw materials.

Filling casings and heat treatment of sausages. Types and modes of heat treatment.

Terms and modes of storage of sausages for baby food. Quality requirements.

Characteristics of the range of shelf-stable sausages.

Features of the technology of long-term storage sausages. Storage conditions and periods. Quality requirements.

Topic 5. Semi-finished meat products for baby and diet food

Characteristics of the range of semi-finished meat products and their composition.

Features of meatball technology. Storage conditions and periods. Quality requirements.

Features of dumpling technology. Storage conditions and periods. Quality requirements.

Features of the technology of meat cutlets and minced meat. Storage conditions and periods. Quality requirements.

Characteristics of the assortment and features of the technology of chopped semi-finished meat products. Storage conditions and periods. Quality requirements.

Characteristics of the assortment and features of the technology of low-calorie meat cutlets and meatballs. Storage conditions and periods. Quality requirements.

Characteristics of the assortment and technology features of minced meat and vegetable semi-finished products. Storage conditions and periods. Quality requirements.

Questions for testing

in the discipline “Technology of baby food products”

Assortment and technology for the production of coarsely ground canned meat, vegetables and fruits and vegetables, cut into pieces.

Assortment of grain-based products. Oatmeal production technology.

Technology of dairy products for children under 3 years of age: sterilized fortified milk, “Children’s” drink and “Vitalakt” fermented milk drink.

Technology of humanized milk powder “Ladushka”.

Questions for deeper study of the discipline

"Technology of baby food products"

Current state and prospects for the development of baby food production.

The role of nutrition in the development of the child's body.

Factors influencing the development of the child's body.

Nutritional value of human milk.

Immunological protection of the child's body.

Regulatory function of mother's milk. Psychophysiology of lactation.

Comparative characteristics of human and cow's milk.

Children's needs for proteins, fats and carbohydrates.

Children's needs for minerals and vitamins.

Basic principles of baby nutrition.

Features of nutrition of children of the first year of life.

Features of feeding newborns.

Nutrition of children in the first months of life.

Features of natural feeding of children over 4 months.

Features of artificial feeding of children of the first 4 months. life. Features of artificial feeding of children over 4 months.

Assortment of grain-based products. Oatmeal technology.

Technology of dehydrated cereal decoctions.

Technology of dietary cereal flour.

Technology of dry mixtures and cereals based on grains.

Technology of dairy products for children under 1 year of age: humanized milk “Vitalakt DM” and “Vitalakt” fortified; sterilized milk mixtures “Malyutka” and “Malysh”.

Technology of liquid milk acidophilus mixtures and fermented milk “Vitalakt”.

Technology of kefir for children and children's cottage cheese.

Technology of dairy products for children under 3 years of age: sterilized fortified milk, “children’s” drink and “Vitalact” fermented milk.

Assortment of dry dairy products and technology of dry milk mixtures “Malyutka” and “Malysh”.

Assortment and technology of humanized milk powder “Ladushka”.

Technology of milk powder "Vitalakt".

Assortment and technology of dry milk product “Detolakt”.

Assortment and technology of dry milk porridges.

Assortment and technology of dry milk-vegetable mixtures.

Technology of dry acidophilic mixtures.

Assortment and technology of Enpity dry mixes for dietary nutrition.

Assortment and technology of dry low-lactose milk mixtures for dietary nutrition.

Assortment and technology of lactose-free fermented milk mixtures for dietary nutrition.

Technology of dry milk product "Cobomil" for dietary nutrition.

Technology of dry milk product "Inpitan" for dietary nutrition.

Assortment and technology of dry milk biological additives for baby food products.

Assortment and technology of canned fish.

Assortment and technology of canned fruit purees.

Assortment and technology of fruit juices with pulp.

Assortment and technology of fruit juices without pulp.

Assortment and technology of compotes for baby food.

Assortment and technology of canned vegetable purees.

Assortment and technology of canned meat and vegetable purees.

Assortment and technology of meat, vegetable and fruit and vegetable coarsely ground canned food and canned food, cut into pieces.

Assortment and technology of vegetable juices.

Assortment and technology of canned vegetables and fruits for therapeutic and preventive nutrition.

Assortment and technology of medicinal canned food with a complex of vitamins and herbal infusions.

Assortment and technology of fruit and vegetable fortifying additives for baby food products.

Assortment and technology of canned meat purees.

Assortment and technology of homogenized canned meat.

Assortment and technology of coarsely ground canned meat.

Assortment and technology of canned meat for therapeutic and preventive nutrition.

Assortment and technology of meat products for therapeutic nutrition of infants.

Assortment and technology of canned meat for preschool and school-age children.

Assortment and technology of sausage products.

Assortment and production technology of shelf-stable sausages.

Assortment and technology of sausage products for therapeutic and prophylactic nutrition.

Assortment of semi-finished meat products and technology for frozen meatballs and dumplings.

Technology of minced meat and cutlets.

Assortment and technology of chopped semi-finished meat products.

Assortment and technology of low-calorie meat cutlets and meatballs.

Assortment and technology of minced meat and vegetable semi-finished products.

Introduction……………………………………………………………………………..3

Laboratory work No. 1. Studying and mastering the determination method

milk buffer capacity………………………………………………………..4

Laboratory work No. 2. Study of the process of membraneless osmosis………8

Laboratory work No. 3. Study of physicochemical parameters

quality of fortified dry milk-vegetable mixtures for

baby food…………………………………………………………………………………...21

Laboratory work No. 4. The influence of heat treatment on structural

components of parenchymal tissue of vegetables and the content of vitamin C………..26

Laboratory work No. 5. Technological basis of vegetable production

and fruit canned food for baby food…………………………………...34

Laboratory work No. 6. Research on fruit processing methods,

increasing the yield of juices………………………………………………………...46

Laboratory work No. 7. Influence of various technological factors

on the structural components of meat……………………………………………………………...60

Laboratory work No. 8. Technological basis for the production of canned meat for baby food……………………………………………………………..65

Laboratory work No. 9. Technological basis for the production of canned fish for baby food……………………………………………………………..77

Laboratory work No. 10. Calculation of biological value and

fatty acid composition of baby food products………………………...83

Bibliography……………………………………………………..94Working programm

... children'snutrition. 4.2.4. Technologyproducts gerodietetic nutrition. The body's nutrient needs for older people. Gerrodietetic products. Basic requirements for productsnutrition ...

Goal of the work: master methods for determining the biological value of products by calculation.

Running time: 2 hours

Devices and materials: methodological instructions for laboratory work, reference literature, textbook, calculator.

Each living organism synthesizes its own proteins, determined by the genetic code formed during the process of evolution. The absence of at least one amino acid (AA) causes a negative nitrogen balance, disruption of the nervous system, and growth arrest. The lack of one amino acid leads to incomplete absorption of others.

If in a given protein all essential amino acids (EA) are in the required proportions, then the biological value of such a protein is 100. For fully digestible proteins with an incomplete amino acid content or proteins with a complete AA content, but not completely digestible, this value will be below 100. If Since the protein is characterized by low biological value (contains an incomplete set of NAC), it must be present in the diet in large quantities in order to meet the physiological needs for NAC, which is contained in the protein in minimal quantities. In this case, the remaining amino acids will enter the body in excess quantities, exceeding the needs. Excess AA will undergo deamination in the liver and turn into glycogen or fat.

Based on their biological value, proteins can be divided into four groups:

1) proteins with nutritional specificity (chicken eggs, fresh and fermented milk). In terms of biological value, these proteins are inferior to those of meat, fish, and soy, but the human body is able to correct the NAC ratio (aminogram) of these proteins at the expense of the NAC fund;

2) proteins of beef, fish, soy, rapeseed, characterized by the best aminogram and, accordingly, the greatest biological value. However, their aminogram is not ideal, and the human body is not able to compensate for it;

3) grain proteins, which have the worst NAC balance;

4) defective proteins, some of them lack NAC (gelatin and hemoglobin).

The biological value of any protein is compared with a standard - an abstract protein, the amino acid composition of which is balanced and ideally matches the needs of the human body for each amino acid. The biological value of proteins depends on the degree of their absorption and digestibility. The degree of digestibility depends on the structural characteristics, enzyme activity, the depth of hydrolysis in the gastrointestinal tract, and the type of pre-treatment during food preparation.

The method for determining the biological value of proteins is the determination of the essential amino acid index (INAC).

The method is a modernization of the chemical scoring method and allows you to take into account the amount of all essential acids:

Where n– number of amino acids;

b– amino acid content in the protein being studied;

uh– amino acid content in the reference protein.

As reference protein used breast milk, casein, whole egg and others. In 1973, by decision of the World Health Organization (WHO, or WFO) and the World Food Organization (WPO, or FAO), an indicator of the biological value of food proteins was introduced - amino acid score(AKS).

When calculating the ACA, the amino acid content in a particular protein is expressed as a percentage of its content in the standard. The amino acid whose ACA has the lowest value is called the first limiting acid. This amino acid will determine the extent to which a given protein is utilized.
The analytical calculation of the biological value of a protein is based on the hypothesis of the dominant influence of the first limiting amino acid.

The disadvantages of the amino acid score method include the lack of consideration of the degree of reutilization of endogenous NAC.

In addition to chemical methods for determining biological value, biological methods using microorganisms and animals are used. The main indicators are weight gain over a certain time, protein and energy consumption per unit of weight gain, the coefficient of digestibility and nitrogen deposition in the body, and the availability of amino acids.

The indicator, determined by the ratio of animal weight gain (kg) to the amount of protein consumed (g), was developed by P. Osborne and called protein efficiency factor (PER).
For comparison, a control group of animals with standard casein protein is used in an amount providing 10% protein in the diet. In experiments on rats, the effectiveness of casein protein is 2.5. Each of the methods has disadvantages.

In accordance with the AKC, grain proteins (wheat) have the lowest biological value, the first limiting AK is lysine, the second is threonine; corn proteins - the first limiting acid is lysine, the second is tryptophan.

Moreover, lysine, which is part of proteins, is lost during heat treatment and undergoes a melanoidation reaction.

Corn proteins are low in lysine but high in tryptophan, while legume proteins are high in lysine but low in tryptophan. A mixture of beans and corn contains plenty of NAC. An example of the same successful combination is bread and milk, rice with soy sauce, corn flakes with milk. Amino acid content in products and biological
the value of some food products is presented in tables P. 7, 8 (Appendix 1).

Calculation of AKS (C, %) is carried out for each NAC according to the formula

C i = A i ∙ 100/A e i,

Where A i –

A e i – content of the i-th amino acid in 1 g of reference protein, mg/g;

100 – conversion factor to percentage.

The limiting NAC is the acid whose amino acid value is the smallest.

The total amount of essential amino acids in the protein of the product under evaluation, which, due to mutual imbalance in relation to the standard, cannot be utilized by the body, serves to assess the balance of the NAC composition according to the indicator of “comparable redundancy”.

This indicator characterizes the total mass of NAC not used for anabolic needs, in such a quantity of the evaluated product that is equivalent in terms of their potentially utilized content to 1 g of standard protein, and is calculated using the formula

Where A i – content of the essential i-amino acid in 1 g of the protein under study, mg/g;

A e i– content of the i-th amino acid in 1 g of reference protein, mg/g;

Cmin

The coefficient of difference in amino acid rates (RAS, %) shows the excess amount of NAC that is not used for plastic needs. It is determined by the formula

Where n– amount of NAC.

The biological value of BC (%) of a protein-containing product is assessed by the value of RED: BC = 100 – RED.

When assessing the biological value of multicomponent products, not only the content of all essential amino acids is taken into account, but also a set of indicators recommended by N. N. Lipatov: minimum speed, coefficient of rationality of amino acid composition, indicator of comparable redundancy.

This coefficient characterizes the balance of NAC in relation to the physiologically necessary norm
(standard). In the case of C min ≤ 1, the rationality coefficient is calculated using the formula

Where k i– utilitarian coefficient of the i-th NAC in relation to the limiting amino acid, fraction of units.

The utility coefficient is a numerical characteristic that reflects the balance of the NAC in relation to the standard. The calculation is carried out according to the formula

K i= Cmin/With i,

Where Cmin– minimum NAC rate of the evaluated protein in relation to the reference protein, fraction of units.

Present the obtained data in the form of table 7.

Table 7

Biological value of the protein under study

Amino acids			AKS, %	RED, %
Amino acids	in reference protein	in the protein under study	AKS, %	RED, %
Isoleucine	40
Leucine	70
Lysine	55
Methionine + cysteine	35
Phenylalanine + tyrosine	60
Threonine	40
Tryptophan	10
Valin	50
Total

Control questions

1. What amino acids are included in proteins?

Laboratory work No. 7

Few people know and understand what amino acid score is. Meanwhile, amino acid score data is very important for those people who temporarily or permanently experience a deficiency of animal proteins in their diet. And because of this, they experience difficulties not only with renewing the body’s muscle structures, but also almost deprive their body of the ability to fully build protein structures.

What is amino acid score

Amino acid score is an indicator of the completeness of a protein, which is the percentage of a certain essential amino acid in a particular product to a similar amino acid in an artificial ideal protein.
In English, the word “score” means score. In the case of an amino acid score, it is a score obtained by dividing the amount of a selected essential amino acid in a food by the amount of the same amino acid in an ideal protein. The resulting figure is then multiplied by 100.
It is good if the amino acid score of any amino acid in a particular product is equal to or greater than 100. In this case, the product is recognized as a complete product in terms of protein and can be recommended for independent consumption.
If any of the amino acids in a particular product shows an amino acid score of less than 100, then this amino acid is recognized as the so-called. limiting.

Limiting amino acids

The presence of limiting amino acids in a particular product does not allow this product to be called complete. The protein of such products is considered inferior, which entails certain difficulties for the synthesis of protein structures in the body.
No difficulties arise if one product with limiting essential amino acids is supplemented with another product in which this amino acid is sufficient.
It is even possible to combine products, in each of which one essential amino acid is limiting, and in the other (other) products - another. Thus they complement each other.
Example: joint consumption in the diet of legumes (lentils, beans, peas), in which the limiting amino acid is methionine, and grains (buckwheat, wheat, rice) with the limiting amino acid lysine.
However, if foods with similar limiting amino acids are consumed, this means a complete deprivation of the body of a component necessary for the construction of body structures.
After all, an ideal protein is called so because it contains the amount of one or another essential amino acid necessary for the body. If any amino acid enters the body in insufficient quantities, this deprives the body of the opportunity to fully renew its structures.
When eating animal protein, no problems with limiting amino acids arise. Problems arise only if you switch to only plant foods.

So, from the point of view of the amino acid score, the following should be remembered: legume products (soybeans, beans - exceptions) have a limiting essential amino acid, methionine.

Cereal products contain the limiting essential amino acid lysine.

The combination of cereals and legumes makes it possible to obtain a complete protein containing all the essential amino acids necessary for the body.

Amino acid score (from the English “score”) is the most important indicator of the usefulness of a protein, which very few people know about. Meanwhile, general knowledge of the amino acid score is simply necessary for vegetarians and people who observe long-term fasts or abstain from foods of animal origin.
The amino acid score of products of plant origin is seriously different from products of animal origin in that in almost all plant products one or another essential amino acid (one that enters the body only with food) is the so-called. limiting. This means that it is impossible for the body to fully build various structures from amino acids.
But first things first.

What is amino acid score

Amino acid score is an indicator of the ratio of a certain essential amino acid in a product to the same amino acid in an artificial ideal protein. (The ideal protein is a ratio of essential amino acids that allows the body to renew certain internal structures without problems.)
The amino acid score is calculated by dividing the amount of a certain essential amino acid in a product by the amount of the same amino acid in an ideal protein. The data obtained is then multiplied by 100 to obtain the amino acid score of the amino acid being studied.

Limiting amino acids

If, after making calculations, the numbers obtained for each essential amino acid are greater than or equal to 100, then the protein of the product is considered complete. Those. one that can independently provide the body with all the necessary ratios of essential amino acids (the amount of protein is another question that goes beyond the scope of the article).
If any (usually one) essential amino acid in a product has an amino acid score of less than 100, then such an amino acid is recognized as limiting, and the protein of the product itself is considered inferior.
The presence of a limiting essential amino acid in a product means that such a product cannot be eaten without combining it with other products that have a sufficient amount of this problematic amino acid.
For example, almost all legumes (soybeans, beans are exceptions) have the limiting amino acid methionine. Therefore, it is necessary to supplement the diet with either protein products of animal origin or those plant products that contain enough methionine.
Another example is cereals, which have the limiting amino acid lysine. They can just be supplemented with legumes. Then, receiving lysine from legumes and methionine from cereals, the body will not experience problems with building protein and blood structures.

Amino acid score table

There is no need to memorize the entire table of the amino acid score of plant products (animal products, as already written, do not have limiting essential amino acids, and their amino acid score is practically unimportant). Just remember that almost all legumes have problems with methionine, and cereals have problems with lysine. A combination of certain cereals and legumes will not only eliminate this problem, but will also solve the problem with the amount of protein in the diet. After all, legumes contain more protein than meat products. True, the digestibility of legumes is far from the digestibility of other protein products.

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Ministry of Education and Science of the Russian Federation

FBGOU URAL STATE ECONOMIC UNIVERSITY

Department of Tourism Business and Economics

PracticalJob

Bydiscipline:Specialkindsnutrition

Ontopic:"GradequalityproductsByamino acidsoon"

Performed:LeonovaON THE.

Group:GS-10

Teacher:LavrovaL.V.

Ekaterinburg2013

Target: study the procedure for calculating the amino acid score of products (dishes, products). Give an assessment of the dish under study.

Theoryquestion:

Amino acidsoon- the ratio of the essential amino acids of the dish to the reference protein (how satisfactory the dish is in terms of amino acid composition).

IrreplaceableAndreplaceableamino acids

Supplying the human body with the necessary amount of amino acids is the main function of protein in nutrition. From the point of view of nutritional science, amino acids are divided into essential and non-essential. It should be emphasized that essential and non-essential amino acids are equally important for the construction of body proteins.

Nine of the 20 amino acids are essential, i.e. they are not synthesized in the human body and must be supplied with food. These include valine, leucine, isoleucine, threonine, methionine, lysine, phenylalanine, tryptophan, histidine. Histidine is classified as an essential amino acid only for newborns. If the amount of these amino acids in food is insufficient, the normal development and functioning of the human body is disrupted.

The remaining 11 amino acids are classified as non-essential. With sufficient dietary intake of protein nitrogen, nonessential amino acids are synthesized using the nitrogen of other nonessential amino acids or the nitrogen of nonessential amino acids.

On the other hand, a certain amount of non-essential amino acids must also be supplied from food. Otherwise, essential amino acids will be consumed for their formation. Glutamic acid and serine are absolutely metabolically replaceable. Modern data indicate that the biosynthesis of non-essential amino acids in quantities that fully meet the body's needs is impossible.

Qualityfoodsquirrel is determined by the presence in it of a complete set of essential amino acids in a certain quantity and in a certain ratio with non-essential amino acids.

The quality of food protein is assessed by a number of biological and chemical methods.

Protein amino acid score

The quality of a food protein can be assessed by comparing its amino acid composition with the amino acid composition of a standard or “ideal” protein. The concept of an “ideal” protein includes the idea of a hypothetical protein of high nutritional value that satisfies the human body’s need for essential amino acids. For an adult, the amino acid scale of the FAO/WHO Committee is used as the “ideal” protein. The amino acid scale shows the content of each of the essential amino acids in 100 g of standard protein.

The calculation of the amino acid score to determine the biological value of the protein under study is carried out as follows. The amino acid score of each essential amino acid in the “ideal” protein is taken as 100%, and in the test protein the percentage of compliance is determined:

NeedVsquirrel- this is the amount of protein that provides all the metabolic needs of the body. In this case, it is necessary to take into account, on the one hand, the physiological state of the body, and on the other, the properties of the food proteins themselves and the diet as a whole. Digestion, absorption and metabolic utilization of amino acids depend on the properties of the components of the diet.

Protein requirements have two components.

The first must satisfy the need for total nitrogen, which ensures the biosynthesis of non-essential amino acids and other nitrogen-containing endogenous biologically active substances. Actually, the need for total nitrogen is the need for protein.

The second component of protein requirements is determined by the human body’s need for essential amino acids that are not synthesized in the body. This is a specific part of the protein requirement, which is quantitatively included in the first component, but requires the consumption of protein of a certain quality, i.e. The carrier of total nitrogen must be proteins containing essential amino acids in a certain amount.

Requirement for essential amino acids at different ages mg/kg/day

Amino acids	Childrenearlyage(3-4 months)	Children(2 years)	Pupils,boys(10-12 years)	Adults
Histidine
Isoleucine


Methionine + cysteine
Phenylalanine + tyrosine

Tryptophan

Total Essential Amino Acids

Amino acid score calculations:

The standard is the content of essential amino acids in the standard protein.

amino acid protein nutrition fast

Dish: Puree soup from various vegetables (No. 186)

Ingredient name	Weight in dish, g	Isoleucine	Methionine	Tryptophan	Phenylalanine
White cabbage
Potato

Bulb onions
Green peas
Wheat flour
Butter




Amino acid score,%

Conclusion: the most deficient amino acid in the dish “Puree Soup from Various Vegetables” is -methionine (6%).

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Amino acid speed What it is? Limiting amino acids

Control questions

Bibliography

Questions for deeper study of the discipline

Laboratory work No. 1. Studying and mastering the determination method

milk buffer capacity………………………………………………………..4

What is amino acid score

Limiting amino acids

What is amino acid score

Limiting amino acids

Amino acid score table

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Amino acid speed What it is? Limiting amino acids

Control questions

Bibliography

Questions for deeper study of the discipline

Laboratory work No. 1. Studying and mastering the determination method

milk buffer capacity………………………………………………………..4

What is amino acid score

Limiting amino acids

What is amino acid score

Limiting amino acids

Amino acid score table

Send your good work in the knowledge base is simple. Use the form below

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