Flours and the gluten complex Flashcards
What us flour?
Tube powder derived from the endosperm of seeds or other starchy foods
What is the most common source of flour?
Wheat
___ is the basis for all baked product
flour
What are 7 types of wheat flours?
1) Whole wheat
2) white
3) bread flour
4) durum semolina
5) all purpose
6) pastry/cake
7) gluten flour
Which flour has bran, germ and endosperm? which one has endosperm only?
Whole wheat
wheat
Which flour is high in gluten?
bread flour
Which what is from hard winter durum wheat?
durum semolina
Which flour has the gluten content that is between cake and bread?
all purpose
which flour is lower in protein (gluten?)
pastry and cake
which flour is milled to retain gluten?
gluten flour
In white flour milled from endosperm, endosperm makes up ___ of the wheat kernel
83%
Why does white flour produce breads with a higher volume and finer texture?
Because gluten forming proteins:
- develep most effective in the absence of germs
- are responsible for the viscoelastic properties of wheat flour dough
Whole wheat flour contains entire ___ kernel
wheat
What has the highest amount of gluten? moderate? lowest?
high: durum wheat, bread flour
moderate: rye, cae flour, barley
low: buckwheat rice quinoa (gluten free)
Which flour are gluten free (RCSBP)
Rice cornmeal soy buckwheat potato
Does rye contain gluten?
yes but in a lower amoiunt
Does critical contain gluten?
yes, it is a hybrid gof wheat and rye
What are the 3 functional properties of starch in flour?
1) strengthens through gelatinization
2) Dextrins contribute to colour and sweetness
3) contribute to crumb
Fine crumbs s are ___
small, densely packed air cells
Coarse crumbs are ___
large, irregular holes
What is the definition of gluten in flour?
Complex mixture of certain proteins that cannot dissolve in water, and form association with each other.
What are 2 keywords when it comes to gluten?
1) Elastic structure (necessary fro rising/structure)
2) It coagulates
What does coagulation mean in baking?
setting
What are the 2 main gluten proteins? how are they produced?
Gliadins and Glutenin
produced by hydration and mixing of the dough
What percent of proteins in flour are gluten? Non gluten?
85% gluten
15 % non gluten
Name 3 properties of gliadin chains
1) hydrophilic, spherical polypeptide chain
2) fold onto themselves, weak bonding
3) fluid and stucky
Name 5 properties of the larger glutenin chain
1) hydrophobic
2) largest gluten complex
3) form S-S bonds at end of chains
3) contribute to elastic properties of the dough
Glutenin =
elastic
Gliadin =
fluid and stucky
Glutenin (elastic) + Gliadin (fluid/sticky) =
Gluten (elastic and plastic)
How can we maximize gluten?
knead under cold water, which allows for water soluble proteins and starch to become freed
Gluten controls ___ properties of dough
rheological 9flow)
What does plasticity and elasticity do?
makes dough more stable
How is gluten formed in baking? (2)
1) Hydration
2) kneading
Name 4 things that happen during hydration
- air bubbles
- gliadin and glutenin absorb 2x their weight in water and become gluten
- other proteins become main part of dough
- result = complex of gluten with water within the spaces
Name 3 things that happen during kneading
- works dough into elastic mass
- expands gluten
- distributes yeast
- warms dough, incr. fermentation and helps distributes Co2
___ coats gluten molecules and prevents cluming
fat
___ binds water and prevents gluten formation
siugar
___ are cross linked by ____
gluten
SS bridges
____ sheets of gluten give a smoother and finer texture
flatter
(T/F) Gliadin and glutting and soluble proteins
FALSE - they are insoluble
What are the 6 soluble flour proteins ?
- Albumins
- Globulins
- Glycoproteins
- Nucleoproteins
- Lipid protein complexes
- Enzymes (amylases and protease)
What affects the baking quality?
quantity and quality of proteins in flour
Gluten is the general name given to what?
Storage proefins (prolamins/peptide fraction) present in BROWS
Which cereal prolaimns are toxic for those with CD?
- GLIADIN in wheat
- SECALIN in rye
- HORDEIN in barley
- AVENIN in oats
What is celiac disease?
- Immune system rxn to gluten
- affects GI trat (malabsorption)
- gentic transmission
What is the prevalence of CD in canada?
1:133
What are some symptoms of CD?
- absominal bloating
- diarrhea
- fatigue
- weight loss
What are the 3 non gluten grains? (RMT)
rice
millet teff
Are oats GF?
appear to be safe, but use limited by potential contamination with gluten
Name 7 GF substitutes for binding
xanthin gum guar gum psyllium seed husk chia seeds flax seed meal gelatin agar agar