Transcript Starch Containing Foods

Characteristics of Starch
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Storage form of carbohydrates in plants
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Sources:
Cereal endosperm
 Wheat
 Corn
 Roots and tubers
 Cassava
 Potatoes
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Characteristics of Starch
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Hot water + Starch = Lump formation
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Starch granules must first be separated
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4 ways:
 Coat starch granules with hot fat
 Coat starch granules with cold fat
 Disperse starch in cold water
 Separate granules using sugar
Characteristics of Starch
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Gelatinization
Starch heated with water
 Viscosity increases
 Maximum viscosity occurs @ 194°C
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Pasting
Occurs when heated beyond gelatinization
 Becomes pasty and swollen
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Composition of Starch
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Amylose
Linear chain of glucose molecules
 Source: Cereal starches
 Include wheat and corn
 Thicken near boiling point
 Retrogradation occurs when chilled
 Becomes rubbery
 Loses water
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Composition of Starch
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Amylopectin
Branched chain of glucose molecules
 Source: Roots and tubers
 Include potato and tapioca
 Thicken at lower temp.
 Becomes clear
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No retrogradation occurs
Starch principles
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Browning
Dextrinization produces pyrodextrins
 Reduced thickening ability occurs
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Factors affecting properties of starch
Temperature
 Length of treatment
 Agitation
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Starch Principles
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Effect of added ingredients to starch
Sugar
 Thins because it competes for water
 Fat
 Thins because it coats granules and prevents
water absorption
 Acid
 Thins because it hydrolyzes starch
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Starch Principles
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Longer cooking times for:
Whole grains
 Brown rice
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Pasta
Includes: macaroni, spaghetti,
vermicelli, egg noodles
 Main ingredient: Semolina
 Composed of Durham wheat and water
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