Why modified food starches are needed

transcript

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

Cornstarch + water

Cornstarch + water + 1.7% acetic acid

Cornstarch + water

effect of Acid on Starch Pasting

Physical Forms of Starch

• Dry

• swollen

• molecular dispersion

• dry film

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