Starch REAL

what type of carb is starch?

polysaacharide

purpose of starch

thickener and gelling in foods, energy in plants roots/seeds

what is starch made of?

glucose linked by glycosidic bonds

amylose function/property

linear, forms gels

amylopectin

branched, cannot form gels, contributes to viscosity

where are starch granules located?

leucoplasts

what are round, polygonal, and ellipsodial examples of

shapes of starch granules

cereal starch characteristics

high amylose/viscosity, high crystalline, gel formation

root starches characteristics

middle amylose/viscosity, less crystalline

waxy starch characterisitcs

high viscosity, high amylopectin, no gel formation

crystalline regions

branched amylopectin (random)

amorphous regions

hydrogen bonded amylose (organized)

gelatinization steps

starch+water+heat, granules absorb water, swell, thicken, paste

gel formation steps

cooled gel paste, amylose molecules create gel network

retrogradation (what happens, affects on gel, what happens to water)

amylose molecules realign, firmer gel, water separation

syneresis steps

removes water during retrogradation

higher amylose=

higher gelatinization temp.

root starches/waxy starches =

lower gelatinization temp. 

Cereal starch paste clarity, gel formation?, retrogradation

opaque, yes, high

root starch paste clarity, gel formation?, retrogradation

clear, no, low

waxy starch paste clarity, gel formation?, retrogradation

cloudy, no, very low

root starch ex.

potato, tapioca

cereal starch ex.

corn, wheat, rice

the more starch you add=

the thicker the product

mixing a product for too long=

thinning

viscous=

thickness

when starch is added to hot liquids it causes=

clumps

how do you prevent clumps?

add separation agents before adding hot liquid

separating agents ex.

fats, sugar, cold water

fats ex.

gravies, sauces

sugar ex.

pudding, desserts

cold water ex.

fat free, sf products

agitation meaning and affect on gelatinization

mixing too much = thinning

concentration of starch affect on gelatinization

more starch = thicker

acid affect on gelatinization

thinner

add acid ____ gelatinization

after

sugar affect on gelatinization

less viscous and viscosity, competes with starch for water, higher gelatinization temp.

fats affect on gelatinization

less viscous, lower viscosity

pregelatinized starch thickens ____ heat

without

when theres high acid and high heat what is there more of

stability

pregelatinized starch function and ex.

swells in cold water, instant pudding

cross-linked starch function and ex.

resists acid/heat, pizza, BBQ sauce

substituted starch function/ex.

stable in frozen foods, frozen sauces

acid modified function/ex.

strong gel on cooling, gummy candies