Starch

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Starch

• FDSC400

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Goals

• Starch structure
• Starch gelatinization
• Modified starches
• Cellulose structure
• Cellulose ingredients

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Starch Composition

• Amylose. Linear a-1,4 glucose chain. DP
  180-320, MW106. Branch approximately every 200
  glucose units
• Amylopectin. Linear a-1,4 chain with an a-1,6
  branch approximately every 20 glucose units.
  MW108
• Amylose amylopectin 13
• Waxy starches all amylopectin
• High amylose mutants up to 70 amylose

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Amylose Structure
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Amylopectin Structure
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Granule Structure
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Amylopectin in Granules
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Visco/Amylo/Graph
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ViscoAmyloGraph
heating
constant temperature
65oC
Viscosity
30oC
90oC
Time
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Starch Ingredients

• Must be cooked
• Gel slowly
• Show syneresis
• Break down under shear
• Break down under acid conditions
• Forms complexes

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Modified Starches

• Depolymerized
• Acid etched
• Acid hydrolyzed
• Enzyme modified
• Pregelatinized
• Chemically modified
• Stabilized
• Cross linked

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Cellulose Structure

• b-1,4 polyglucose
• Very large molecule
• Crystalline (hydrogen-bonded) and non-crystalline
  regions

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Cellulose Ingredients

• Microcrystalline Cellulose
• Carboxymethyl cellulose
• Methyl cellulose and hydroxypropyl methyl
  cellulose