TECHNIQUES FOR STARCH MODIFICATION

TECHNIQUES FOR STARCH MODIFICATION
- Acid conversion.
- Amylopectin > amylose. 
Hot concentrated pastes. Gel formation on cooling. Gum candies. Decreased hot paste - viscosity.Decreased gel strength. Increased gelatinization temperature
Hydroxyethyl straches.
- Reduced gelatinization temperature. Increased rate of swelling. Lower tendency of pastes and gels to retrograde
- Hydroxy propyl starches
- Propylene oxide. Salad dressings, pie fillings, thickening

Starch phosphates - Lower gelatinization temperatureswelling in cold waterincreased paste viscositydecreased retrogradation
- Starch acetates
- inhibit association of amylose and long chains of amylopectin. Low D.S. 0.05 - 0.10 Low gelatinization temperature.Resists retrogradation after pasting and cooling
- Cross-linked starches. Diesters or links between OH groups in adjacent chains. 


Uses of cross-linked starches
Stability to heat, agitation, hydrolysis, low pH. Swelling can be inhibited in hot or boiling water. Used in infant foods, pie fillings, salad dressings, stabilizers and thickeners.


Example of stabilisation
Hydroxypropylation of starch with propylene oxide
StOH + CH2-CH-CH3-------- StOCH2CHCH3

Hydroxypropylation of starch with propylene oxide
StOH + CH2-CH-CH3-------- StOCH2CHCH3OH


REFERENCE :
Yenni.2009.PROCESSING TECHNOLOGY OF PLANT FOOD.Lampung University. Bandarlampung DERIVED OH