Cereal Grains And Grain Products

Question 1

Wheat genus and genera?

Answer 1

All wheats belong to the genus Triticum
2 main genera
1. Durum - good for pastas
2. Vulgare

Question 2

Wheat Anatomy

Answer 2

Endosperm - is the inside (the good stuff) has 65% starch and lots of protein. Makes up 83% of kernel.
Germ - or embryo is what the wheat grows from. Contains lipid and vit E
Bran - the outer layers on the wheat (used when making bran bread) 14% of kernel contains the most fiber and ash

Question 3

Flour Milling Process

Answer 3

-Wheat is brought in and stored
-Product control is done and blending may occur at this step as well
-separator is used to remove stones and sticks
- aspirator - air currents remove lighter materials
-disc separator removes cockles and the like
-scourer scours off impurities and roughage
-magnetic separator to remove iron or steel particles
-washer to remove water stones
-tempering water coats outer bran for easy separation, also softens the endosperm
-blending types of wheat to make specific flours
-first break - corrugated rolls break wheat into course particles
-sifter to increase fineness
-purifier
-reducing rolls
The purifier, reducing rolls and sifting is repeated

Question 4

Define Tempering

Answer 4

Water is introduced as a mist and takes 18-72 hrs to equilibrate. The idea is to toughen bran and soften endosperm when is more easily milled when soft.

Question 5

Quality of baked products depends on …?

Answer 5

Gluten - gives ability to form cohesive mass of dough that is elastic yet malleable through disulfide bonds
Starch -gives ability to hold water, also responsible for starch retrogradation (the bread going stale)

Question 6

Gluten

Answer 6

Is found only in wheat flour and related grain species like barley, rye and oats
Is responsible for cohesiveness (holding together) and film forming properties on bubbles
Formed during mixing period through the hydration of original flour proteins (gliadin and glutenin)

Question 7

Starch

Answer 7

As water is absorbed by the flour, starch granules swell and get gradually released of amylose from gelatinization, upon standing and cooling, amyose forms an H-bonded gel (gelation). Aging causes toughening of the crumb (staling) due to retrogradation of the starch.

Question 8

What are the four methods of Bread Dough production?

Answer 8

1. Straight dough process - all ingredients are mixed together at the same time. Takes less labour and time than the sponge dough method. Produces blander flavour.
2. Sponge dough process (2 steps)
   - slurry is made with no gluten
   - fermentation before adding remaining portion of ingredient mix
3. Liquid fermentation process
   Initial fermentation carried out with water, yeast, sugar, milk powder salt and yeast food. Second step is to add flour and additional yeast and fat. Saves time.

Question 9

Bread manufacturing process

Answer 9

1. Dough mixing in reel type mixer used to blend ingredients and hydrate yeast and flour.
2. Dough placed in trough and allowed to rise in a ‘fermentation cabinet’ for a day.
3. Divider breaks dough into loaf size pieces
4. Rounder spins each dough piece in a ball. At this point the dough forms a skin to protect it from dehydration and CO2 escaping.
5. Intermediate Proofing for 8 mins. In necessary bc CO2 is lost in the rounder and loss in pliability and volume.
6. Molding involves redistribution of gas bubbles through the dough
7. Proofing
8. Baking as temp increases CO2 expands and is lost as it dissolves. Volume increases and water goes from centre of loaf to the crust. Crust becomes crisp and brown as the water evaporates