HomeEc- Cereals

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types of cereals

• wheat

• rye

• oats

• barley

• maize

• rice

Structure of wheat grain (and percentages)

• Bran (13%)

• Endosperm (85%)

• Germ (2%)

Bran description

• tough layer of cellulose, indigestable to the human body

• contains B group vitamins,esp B3, calcium, non-haem iron and phosphorus

Endosperm description

• main part of wheat grain

• made of starch, B group vitamins and protein gluten

• outer layer called aleurone layer, contains LBV protein

Germ description

• base of cereal grain

• rich in LBV protein

• contains B1, E, non haem iron, polyunsat. fat and essential fatty acids

• thin layer between germ and endosperm = scutellum

Types of wheat

winter and spring

winter wheat

• main wheat

• makes low protein flour (less than 10%)

• grown in climates with mild winters

Spring wheat

• high protein flour (12-14%)

• more suitable for bread making

• grown in climates with cold winters and hot summers

Nutritional composition of wheat

Protein value of cereals

• LBV protein

• main protein in wheat and rye = gluten

• essential amino acids lysine, threonine and typtophan lacking

• eat with combo of other LBVs

Fat value of cereals

• germ has polyunsat with essential fatty acids

Carbohydrate value of cereals

• good source

• 64% starch

• outer husk has fibre, removed during refining

Vitamin value of cereals

• B group, especially B1, B2 and B3

• small amount of E in germ

• lacks C

Mineral value of cereals

source of iron, calcium and phosphorus

Water value of cereals

• varies slightly

• typically low

Dietetic value of cereals

• source of starch for energy

• outer husk has fibre for bowels

• polyunsat fat, increase HDLs to lower LDLs

• LBV protein for vegans and vegetarians

• versatile

• inexpensive

• phytic acid inhibits calcium and iron absorption, binds to nutritens

• gluten cant be digested by coeliacs

Guidelines for buying cereals

• strict food hygiene policy (HACCP)

• check best before date

• ensure packaging properly sealed

Guidelines for storing cereals

• cool, dry, well-ventilated space

• store in airtight container after opening

• label with name and best before date

• minimise time in storage

• use before best before date

Effects of cooking on cereals

• moist heat = grains swell, burst and absorb liquid

• dry heat = grains swell, burst and absorb fat

• cellulose and starch softens and becomes digestable

• protein coagulate in dry heat

• B group vitamins lost

• dextrinisation of starch

• caramelisation of sugar

What is milling

the processing of wheat to produce wheat flour

Stage one in milling (wholemeal flour production)

Preparing:

1. screening: sieves remove sticks, stones, dirt, soil and dust

2. cleaning: scoured (cleaned by scrubbing) to remove beard and washed

Milling:

1. Conditioned: water added to make it easier to mill and roll

2. Blending: types of wheat blended into grist

3. Break rolled: pass through rotating metal ridged rollers, peeled open, endosperm released without breaking outer bran (wholemeal flour produced)

Stage two in milling (white flour production)

1. Sifted and purified: wheat grains pass through series of rotating sieves, starts with coarse mesh siev to separate bran and germ from rough endosperm

2. reducing rollers: ramining endosperm ground by rollers

3. Air classified air introduced for lighter flour

4. Addition of additives: bleach, nutritives, improvers

5. Packaging and labelling

Wheat products

• flour

• wholemeal bread

• pasta

• breakfast cereals

Pasta description

• made from endosperm of durum wheat (high gluten content)

• endosperm ground into semolina flour and mixed with eggs, water, salt and oil

• dough moulded into various shapes

• sold dried or fresh