Cereal

1moisture-lower moisture grains more expensive,less storages better,before milling conditioning(10-15% moist)limits break-up&improves separation

2cellulose

3starch-largest,a-glucose polymer.Must be heated to eat(Hbonds break)-gelatisation

4protein(12-14%)-protein quality is the physical characteristics of gluten.High level of protein-good yield of gluten-good for bread,but extensible gluten for cakes.Gluten-gliadins(30%),glutenins(60%,coiled protein subunits linked by disulphide links from oxidised cysteine).They are little ionic&are insoluble.When water is added dough is formed(stronger when more glutein)

Kjeldahl method determines protein content-grain digested in H2SO4,N2 leaves&is measured

5some fat

6vitamins+minerals

 

Processing

AWheat to flour

1Conditioning to uniform moisture by adding H2O&leaving

2Gristing by blending together different wheats to adjust protein

3Milling&blending to produce required protein+colour(endosperm colour,particle size,bran contamination).Flour is broken by rolls to bran&endosperm

BAdditives

1CaCO3 to increase Ca content in diet

2Vitamins&Fe

3Improvers(KBrO3)to control cross-linking

CFlour to bread

1On heating starch granules in the flour swell&take up large amounts of H2O

2Soluble starch leaks out of granules&the suspension becomes more viscosious

3Added yeast converts glucose>CO2+ethanol,that escapes,but CO2 is traped,makes to rise

Bread making properties improve with standing(unsaturated acids get oxidised by peroxides),whiter&more elastic(SH>SO3H).Nowadays flour is bleached with Cl or ClO2

Good dough holds gas, made by kneading(glutein is stretched linearly to break molecules,cystein exchanges disulphide).Improving agents become active when water is added(vit,C,oxidises SH).Ca is added

In dough amylase is hydrolysed to maltose.Starch on heating will dissolve&take up H2O.Gelatinised starch is more readily hydrolysed by our body enzymes.Yeast is added to produce CO2 that is trapped by gluten,that later in high t coagulates.Salt is added to control rate of fermentation

In UK Chorleywood Bread Process(instead of fermentation,high speed vacum,starch damage,soft crumb,fast,cheap)

Gluten test is SDS sedimentation(shake)

Gelatisation temp.microscope or heat

Pour 2%iodine solution over wet flour.Blue with white spots,because ascorbic acid reduces iodine to iodide,Add thiocyanate to flour,red spots appear where iron is