Food Proteins - Wheat, Flour, Gluten

Question 1

What is the bran of a grain and what does it contain?

Answer 1

The outer layer
Fibre-rich
B vitamins

Question 2

What is the endosperm of a grain and what does it contain?

Answer 2

The middle layer
Carbohydrate
Protein

Question 3

What is the germ of a grain and what does it contain?

Answer 3

The core
Nutrient rich
Antioxidants

Question 4

What parts of the grain do wholemeal products contain?

Answer 4

The bran, endosperm and germ

Question 5

What parts of the grain do white grain products contain?

Answer 5

Just the endosperm enrichedwith vitamin B1, iron and calcium

Question 6

What is the biological definition of gluten?

Answer 6

A protein complex derived from cereals

• Wheat
• Rye
• Barley
• Oats

Question 7

What is the food science definition of gluten?

Answer 7

A viscoelastic byproduct derived from the isolation of starch from wheat flour
- Dough forming protein

Question 8

What is vital wheat gluten?

Answer 8

Gluten sold in dry state

Question 9

How is vital wheat gluten produced?

Answer 9

From wheat flour by wet separation and controlled drying

Question 10

What does vital wheat gluten retain when rehydrated?

Answer 10

Gluten properties = a cohesive viscoelastic mass

Question 11

What is vital wheat gluten traded as?

Answer 11

An additive for bread manufacture and an ingredient for other food and non-food uses

Question 12

What properties does vital wheat gluten have?

Answer 12

Forms a viscoelastic cohesive mass when rehydrated
High water holding capacity
Thermosetting properties

Question 13

How is vital wheat gluten sold?

Answer 13

As a cream coloured powder

Question 14

What are the challenges involved with trading vital wheat gluten?

Answer 14

• Modest price when compared to alike products
• Not high in biological value when completely isolated
• There is no research into the nutritional advantages
• Disadvantaged due to the link with coeliac disease

Question 15

How is the world production of vital wheat gluten changing over time?

Answer 15

Increasing

Question 16

How is gluten extracted from flour?

Answer 16

1. Mix flour and water to produce a dough/batter
2. Leave dough to rest and fully hydrate = produces gluten protein agglomerates
3. Agglomerates are separated from starch by centrifugation
4. Drying, grinding and sieving obtains vital when gluten powder

Question 17

How are lipids obtained in vital wheat gluten?

Answer 17

Flour lipid content binds to hydrophobic areas on gluten proteins during washing

Question 18

What percentage of protein must vital wheat gluten contain?

Answer 18

80%

Question 19

What are the main gluten proteins?

Answer 19

Glutenin and Gliadin

Question 20

What are the properties of glutenin?

Answer 20

Polymeric
Strands
High molecular weight glutenin contains a high percentage of sulphur which allows formation of disulphide bonds

Question 21

What property of gluten is glutenin responsible for?

Answer 21

Elasticity = the ability to return to its original shape once stretched

Question 22

What are the properties of gliadins?

Answer 22

Monomeric
Globular
Act as a fillar between glutenin strands

Question 23

What are the four types of gliadin?

Answer 23

Alpha
Beta
Gamma = high percentage of sulphur which allows the formation of disulphide bonds
Omega

Question 24

What property of gluten is gliadin responsible for?

Answer 24

Extensibility = the ability to stretch

Question 25

What process can be used to determine the proportions of glutenins and gliadins?

Answer 25

Electrophoresis

Question 26

How are glutenins and gliadins associated?

Answer 26

Disulphide bonds Hydrogen bonds Hydrophobic interactions

Question 27

What are glutens unique physical properties and how are they achieved?

Answer 27

Viscosity Extensibility Elasticity Achieved by the balance of glutenins and gliadins

Question 28

What amino acids are found in gluten?

Answer 28

High levels of essential amino acids except lysine | High levels of glutamine = non-essential amino acid

Question 29

What are the functional properties of gluten?

Answer 29

1. Solubility and water holding capacity 2. Viscoelasticity 3. Flavour 4. Thermosetting

Question 30

Is gluten soluble or insoluble in water and why?

Answer 30

Insoluble because the components of gluten are held together by strong covalent and non-covalent bonds

Question 31

Is glutens water holding capacity high or low and how is this advantageous?

Answer 31

High - Improves yield - Lengthens shelf life

Question 32

What does the elasticity of gluten allow for and why is this?

Answer 32

Controlled expansion whilst maintaining strength because there are only a few charged amino acids present meaning protein molecules can associate very close together and resist dispersion

Question 33

What is the flavour of gluten and how can it be improved?

Answer 33

Bland - can taste rancid due to lipid oxidation - Blending with other proteins - Blending with soy improves nutritional quality

Question 34

What do the thermosetting qualities of gluten provide?

Answer 34

Structural rigidity

Question 35

How can gluten be modified?

Answer 35

By increasing solubility for emulsions and foaming | Physical treatments

Question 36

How is gluten modified to increase solubility for emulsions and foams?

Answer 36

- Deamidation with acid or alkali treatment = meat and milk replacements - Enzymatic hydrolysis of peptide bonds = dough

Question 37

What physical treatments can be used to modify gluten?

Answer 37

- Texturisation by extrusion = stimulates meat fibres - High pressure = makes gluten more liquid like - Low pressure increased = makes gluten more solid

Question 38

What are the uses of wheat gluten?

Answer 38

``` Flour fortification in bakery Breakfast cereals Pasta and noodles Processed meat, poultry and fish Veggie meat and cheese replacements Asian food Pet food Agriculture feed ```

Question 39

What are the non-food uses of wheat gluten?

Answer 39

Edible films | Skincare and haircare

Question 40

How is gluten used in fortifying flour for baking?

Answer 40

Increases protein content | Improves nutritional quality

Question 41

How is gluten used in breakfast cereals?

Answer 41

Improves nutritional quality Helps binds minerals and vitamins Contributes to textural strength of flakes

Question 42

How is gluten used in pasta and noodles?

Answer 42

Reduces stickiness | Increases resistance to breakage

Question 43

How is gluten used in processed meat, poultry and fish?

Answer 43

Converting less desirable cuts into more palatable products | Binds mince which can improve slicing

Question 44

How is gluten used in veggie meat and cheese substitutes?

Answer 44

Binding of meat replacements | Texture of synthetic cheese

Question 45

How is gluten used in asian food?

Answer 45

Soybean meat substitutes Soy sauce Deep fried gluten balls

Question 46

What does vital wheat gluten need to be approved for?

Answer 46

Certain uses - Dough strengtheners - Stabilisers - Thickeners

Question 47

What is coeliac disease?

Answer 47

The inflammation of the small intestine due to an inappropriate immune response to wheat gluten

Question 48

What is the current treatment for coeliac disease?

Answer 48

Strict diet

Question 49

What is a potential treatment for coeliac disease?

Answer 49

Oral enzyme supplements designed to accelerate gastrointestinal degradation of gluten