Gluten

Question 1

outline the components of a whole grain

Answer 1

bran
endosperm
germ

Question 2

outline the components of a white grain

Answer 2

endosperm

Question 3

what is the bran?

Answer 3

the fibre rich outer layer that provides protection

Question 4

what is the endosperm

Answer 4

the middle layer containing carbohydrates and proteins

Question 5

what is the germ

Answer 5

the core that contains antioxidants and fat

Question 6

uses of hard white wheat flour

Answer 6

pasta

Question 7

uses of soft white wheat flour

Answer 7

cake, biscuits

Question 8

uses of hard red wheat flour

Answer 8

bread

Question 9

what has to be added to white bread by law

Answer 9

vitamin B1, iron, calcium

Question 10

what has to be added to wholemeal bread by law

Answer 10

nothing

Question 11

what is gluten

Answer 11

a proteinaceous material prepared as a cohesive, viscoelastic by-product derived from the isolation of starch from wheat flour

Question 12

what is vital wheat gluten

Answer 12

gluten in its dried state
it is produced from wheat flour by wet separation and controlled drying
it is an additive in bread manufacture
it retains the original properties of gluten upon rehydration

Question 13

what is commercial wheat gluten

Answer 13

a cream coloured powder that is mixed with water. to form a cohesive viscoelastic mass

Question 14

what are the advantages of gluten in the industry

Answer 14

sold at a modest price

Question 15

what are the disadvantages of gluten in the industry

Answer 15

not high in biological value
not widely researched
has a link to coeliac disease

Question 16

what is the manufacturing process for gluten powders

Answer 16

mix flour and water to form a dough, allow the dough to rest
once fully hydrated, the gluten protein agglomerates are produced, they are then separated from starch via centrifugation in decanters
they are then dried, ground and sieved to obtain a powder

Question 17

are gluten proteins hydrophilic or hydrophobic

Answer 17

hydrophobic

Question 18

what should the composition of protein in dry gluten be based on the Codex standard

Answer 18

must contain at least 80% protein

Question 19

name the two protein in gluten

Answer 19

Glutenin

Gliadin

Question 20

what is glutenin

Answer 20

polymeric strands with a high molecular weight, responsible for the elasticity of gluten

Question 21

what is gliadin

Answer 21

a monomeric molecule responsible for the extensibility and viscosity of gluten
acts as a fller
4 types
- alpha
-beta
- gamma
-omega

Question 22

what is the relationship between gluten and its amino acid composition

Answer 22

high content of essential amino acids and high levels of glutamine

Question 23

outline the structure of gluten

Answer 23

glutenin and gliadins are associated through disulfide bonds, non-covalent hydrogen bonds and hydrophobic interactions- which provide gluten with viscosity, elasticity and extensibility

Question 24

what are the properties of gluten

Answer 24

solubility and good water holding capacity

• gluten is insoluble in water
• when mixed with water a gel is formed

viscoelasticity
- low content of charged amino acids are linked to a close association and a resistance to dispersion

flavour

• can be blended to improve flavour
• off flavours are caused by rancidity due to lipid oxidation

thermosetting
- permanent hardening improves structural rigidity and bite characteristics

Question 25

how can the properties of gluten be modified

Answer 25

chemical modifications - increasing water solubility chemically for foam and emulsion stabilisation

• deamination: done with either an acid or alkali, removes the amine group from the amino group
• enzymatic hydrolysis of peptide bonds

physical modifications

• texturisation by extrusion, which produces a fibrous structure to stimulate meat fibres
• high pressure

Question 26

what are the uses of gluten

Answer 26

milling
flour fortification (improves protein content)
noodles
cereal, processed meat, pet food (acts as a binder)
baking
pasta (reduces stickiness)

Question 27

what is the name of the disease that causes gluten intolerance

Answer 27

coeliac disease

• inflammation of the small intestine due to a inappropriate immune response to wheat gluten, affecting water and nutrient absorption
• treatment= diet modification