why modified food starches are needed
Post on 19-Jan-2015
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Formation and Applications of Modified Starch in Food
Industry
K.D.ChanudiSeminar in Food Science and Technology
Department of Food Science and TechnologyFaculty of Agriculture
Why Modified Food Starches are Needed ?
Reasons for Modifying Starches
• Provide functional attributes
• abundant and readily available
• provide an economic advantage
Problems of Native Starches
• Narrow Peak Viscosity Range
Texture and Stability Limitations
• Poor stability
• Poor processing tolerance
• Cohesive texture
• Insolubility in cold water
• Loss of viscosity
Applications of ModifiedStarch Products
Sauces(Mayonnaise)• Water binding capacity• Thickening• stabilization
Beverages (Tea, coffee) • Stable emulsions• Good dispersibility• High solubility• Low viscosity
Jellies
• Texture similar to gelatin• As a ingredient• Easy to disperse
Ice-cream• Thermal stabilization• Water binding capacity • Thickening • Texture development• Provide bulk
Types of Modified Food Starches
• Physical Modification
• Chemical Modification
• Enzymatic Modification
• Genetic Modification
Physical modification
• Heat - moisture treatment
• Annealing
• Retrogradation
• Pregelatinization
Chemical Modification
• cross - linking
• Esterification
• Acid Treatment
• Oxidation
Functional Advantages
Heat - moisture treatment
• decrease granular swelling
• decrease peak viscosity
• increase gelatinization temperatures
• decrease amylase leaching
• increase thermal stability
Cross linking
• Reduce peak viscosity
• increase stability
• increase freeze thaw stability
Oxidation
• lower dispersion viscosity
• retard recrystallization
Acid Treatment • Decrease viscosity
Vis
cosi
ty
Time
Cornstarch + water
Cornstarch + water + 1.7% acetic acid
Vis
cosi
ty
Time
Cornstarch + water
Cornstarch + water + 1.7% acetic acid
Vis
cosi
ty
Time
Cornstarch + water
Cornstarch + water + 1.7% acetic acid
effect of Acid on Starch Pasting
Physical Forms of Starch
• Dry
• swollen
• molecular dispersion
• dry film
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