Year 10 Food Technology 1 - PowerPoint Presentation

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Year 10 Food Technology

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Nutrition

Function of Proteins

What does Protein Do?Protein has a large number of important functions in the human

body. The human body is about 45% protein. Without protein our bodies would be unable to repair

, regulate, or

protect themselves.

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We are Protein!!3

We are protein...

Functions of Protein

.

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Needed for building

a

nd repair of body tissues Needed to make enzymes and

hormones. Essential for water balance, nutrient transport

and muscle

contractions

Functions of protein

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Protein is a source of

energy

( 1g protein provides 17kj/4kcal)Protein helps keep skin, hair, and nails healthy.

Protein, like most other essential nutrients, is absolutely crucial for overall good health.

FunctionsProtein is essential:

as a secondary source of energy if the body receives insufficient energy from carbohydrates and fat sources

Proteins come from mainly foods from animals but there other foods rich in protein which are derived from plants!!

Veggies eat proteins extracted from soya beans and fungi

Sources of Protein

Proteins

Made of amino

acids (building blocks of all proteins

)

Amino

Acids

Carbon

Nitrogen

Hydrogen

Oxygen

COMPOSITION OF PROTEINS Proteins are made up of complex chains of amino acids

. Amino acids can consist of between 50 and tens of thousands of amino acids.

20 different amino acids are required in the body, each with a specific functionFor healthy growth and repair of the human body, you will need all 20 amino acids

COMPOSITION OF PROTEINS Some amino acids can

NOT be made in the body

and need to be obtained from the food you eat.

These are called ESSENTIAL AMINO ACIDS ( indispensable)

Composition of proteins

Amino acids which can be made by the body are called:

NON-ESSENTIAL AMINO ACIDS ( dispensable)

Composition of proteins

For Adults

, 8 amino acids have to be provided in the diet. These include:LycineValine

Children require 7 amino acids to be provided by the diet. The most important being

histidine.Conditionally essential amino acids

need to be obtained from food sources at certain life stages because they cannot be produced in sufficient

quantities to satisfy the needs of the body

How much protein do we need?

children

1 t -3 yrs15g

4-6 yrs20g

7-10 yrs28g

11-14 yrs42g15-18

yrs55g

Adults

19-50

yrs

55g

50

yrs

+

53g

The amount of protein needed in the diet depends on the person’s weight, age and health. As a rough guide the RNI ( REFERENCE NUTRIENT INTAKE) for protein is:

LOW BIOLOGICAL VALUE FOODSFoods that are deficient in one or more of the ESSENTIAL AMINO ACIDS are said to have:A LOW BIOLOGICAL VALUE (LBV)

These are foods originating from plants. For e.g. cereals, nuts seeds, lentils, beans pulses.

HIGH BIOLOGICAL VALUE Foods containing ALL the essential amino acids are said to have:A HIGH BIOLOGICAL VALUE

Foods originating from animal sources are said to Are all HBV foods.These include, meat, fish, eggs,

cheese & milk

SOYA & QUORNThese are the only two non animal derived HBL foodsSoya products are derived from soya beans ( Tofu, textured vegetable protein (TVP), soya sauce, tempeh and miso

Quorn products are derived from an edible fungus: mycoprotein.

Soya and quorn products have been promoted as healthy high protein foods and meat substitutes.

Summary

Low Biological

Value FoodsHigh Biological Value Foods Contain all essential amino acids

Only contain some of the essential

amino acidsCalled high biological value foods.

Called low biological value foods.

Mostly found in dairy products e.g. meats, fish, poultry, cheese, eggs, yogurt, and milk) Seafood and soya beans are also complete proteinsMostly found in plant foods e.g. legumes,

grains (

Wheat, Oats, Rice, Barley, Corn)

, seeds and vegetables.

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Estimated average daily

requirement – Protein

You can calculate the estimated average daily requirement (EAR) for protein using this formula:

EAR in g = 0.6 × body mass in kg

For example, what is the EAR for a 60 kg person?

EAR = 0.6 × 60 = 36 g of protein

Combining proteins

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By combining foods

a complete protein meal can be made and your body receives all nine essential amino

acids

E.g. Peanut butter on wholemeal breadBeans on toast

Tofu-vegetable

stir-fry

.

By combining 2 or more LBV proteins creates complementary proteins

To obtain the required balance of amino acids vegetarians need to include a variety of protein sources a combination of plant foods in their daily diet

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What happens when you don’t get enough protein

Symptoms

:

Loose

weight

.Tissues waste away.

Ribs

become visible.

Fat belly because digestion is affected.

The body becomes frail and weak.

Eyes appear sunken.

Brain damage and death

Protein deficiency

Symptoms include a badly swollen abdomen

Kwashiorkor is a type of protein energy malnutrition

Who is at risk

Infants and children in underdeveloped countries 

Those around the world who live in extreme poverty

Causesoverpopulation (too many people for the land and resources available)