BF-LEC STARCH AND ALIMENTARY PASTE

starch

Germanic term root word meaning "stiff"

starch

acts as a thickening or gelling agent in food preparation

wheat, rice, and corn

common sources of starch

potato starch

size: largest granules

corn, tapioca, rice, and taro root

size: progressively smaller

Gelatinization

Occurs when starch granules are heated in a liquid, causing hydrogen bonds holding starch together to weaken, allowing water to penetrate and starch molecules to swell until peak thickness is reached.

Gelation (Gel Formation)

When a fluid starch paste (sol) cools down to become a semisolid paste (gel). This depends on having enough amylose molecules, which form strong bonds unlike the highly branched amylopectin.

Retrogradation

The seepage of water out of an aging gel caused by contraction and reassociation of gel bonds between amylose molecules. Also called syneresis or weeping, where the gel network shrinks and water is expelled.

Dextrinization

The breakdown of starch molecules into smaller, sweeter dextrin molecules due to dry heat exposure. This increases sweetness but reduces thickening power.

Syneresis

The process where water is expelled from an aging gel as the gel contracts, synonymous with retrogradation.

Resistant Starch

Starch that is not digested and does not contribute calories. It can aid weight loss, improve blood glucose management, colon health, and energy.

RS1, RS2, RS3

Types of Resistant Starch

RS1

Physically inaccessible starch granules trapped in food and prevented from gelatinizing.

RS2

Indigestible starch granules due to their chemical structure.

RS3

Retrograded starch formed during heating and cooling that becomes resistant to enzyme digestion.

RS4

Modified starches chemically altered to improve their functionality in food processing.

Starch

A polysaccharide made of long chains of glucose molecules, primarily amylose (linear) and amylopectin (branched), used as a thickening or gelling agent in food.

Pasting

The continued heating of starch-water mixtures causing further granular swelling, leaching of soluble components like amylose, and granule disruption after gelatinization.

Edible Films

Protective coatings for chewing gum and food binders in meat and pet food products.

Thickening Agent

Used in soups, sauces, pies, gravies, and desserts to provide viscosity and texture, often derived from starch.

Pasta

Made from flour starch and water, sometimes with eggs (then called noodles). The dough is shaped by extrusion and cooked by boiling.

Al dente

Italian term meaning "to the tooth," describing pasta that is tender but firm enough to offer resistance when bitten.

amylose

made up of primarily linear molecules

amylopectin

whose molecules are highly branched

gel

Starches containing higher levels of amylose tend to __________________

gummy

starches containing higher levels of amylopectin are considered non-gelling, but are still somewhat ________________

Thickening Agent

-soups, sauces, pie fillings, gravies, chili, stews, cream-style corn, cream fillings, custards, fruit pie fillings, whipped toppings, and icings.

-certain puddings, candies, gums, and salad dressings are also thickened with starch

Edible Films

-Protective coating for chewing gums

-Food binder (meat products, pet foods

-Acts as a base on the food for holding

substances (flavor oils in chocolates)

Dextrose

-Glucose derived from starch (food industry)

-Repeating units of glucose

-As a sweetener in the production of confections, wine, and some canned goods

• Gelatinization:

Water, Temperature, Timing, Stirring, Presence of acid, sugar, fat, and protein

• Pasting

• Gel Formation / Gelation

• Retrogradation

• Dextrinization

Starch Characteristics

Gelatinization

occurs when starch granules are heated in a liquid

Water, Temperature, Timing, Stirring, Acid, Sugar, and Fat/Protein

Factors Influence Gelatinization

33°F-167°F (56°C-75°C)

Most starches gelatinize when heated above __________

140°F (60°C)

Thickening usually begins at approximately ______________

warmed

In ___________ liquids, the starch granules swell and burst, releasing more starch particles into the liquid.

Starches

do not dissolve in cold or room temperature liquids

water

Sufficient _______________ must be available for absorption by the starch.

True

The amount of liquid needed for absorption depends on the concentrations of amylose and amylopectin in the starch.

True

When preparing starchy foods such as grains or pasta, sufficient water is added to not only cover the food but also allow for evaporation and a two to three times expansion in volume.

decreases

Heating beyond the gelatinization temperature _______________ viscosity

heating

Starch granules break apart when continued _________________ stresses the bonds holding them together.

Stirring

______________________ during the early formation of the starch paste, or the gelatinizing starch mixture, is required in order to ensure uniform consistency and to prevent lumps from forming

True

Continued or too vigorous stirring, however, causes the starch granules to rupture prematurely, resulting in a slippery starch paste with less viscosity

Acid

will weaken the ability of starches to thicken

4.0

a pH below _______________ decreases a starch gel's viscosity

True

Any acidic fruit juices should be added to pie fillings or salad dressings after gelatinization has occurred.

Sugar

competes with starch for available water, delays the on set of gelatinization, and increases the required temperature

True

Adding too much sugar inhibits complete gelatinization and results in a thick, runny paste

Fat or protein

delays gelatinization by coating the starch and preventing it from absorbing water.

Pasting

The heating of the starch-water mixture continues after gelatinization, further granular swelling, leaching of soluble components (often amylose), and disruption of the granules occur.

sequential processes

Gelatinization and the development of a viscous starch paste are generally described as ____________

sol

fluid starch paste

gel

semisolid paste

cooling

Gelation takes place on ____________ of the starch

paste after the starch granules have been

gelatinized.

True

Gel formation in cooked starch pastes is agradual process that continues over severalhours as the paste cools.

Gel formation

is dependent on the presence of a sufficient level of amylose molecules because amylose will gel and amylopectin will not

Gel Formation

The linear amylose molecules form strong bonds, whereas the highly branched amylopectin molecules form bonds that are too weak to contribute to rigidity

Retrogradation

Also known as syneresis or weeping, the gel network shrinks, and water is pushed out of the gel.

freezing

This retrogradation is accelerated by ____________, so the starches used in frozen food products usually come from sources low in amylose, such as waxy corn or sorghum.

energy value of protein

It results in an increase in sweetness

dextrin

The breakdown of starch molecules to

smaller, sweeter tasting ________________

True

A side effect is that dextrinized starches lose much of their thickening power because they have been broken down into smaller units; thus, more flour is required to thicken gravy if the flour has been browned in the gravy-

making process

Resistant Starch

Starch that is not digested and therefore, does not contributes calories

Resistance Starch

Can be used for weight loss purposes, improve glycemic

management (blood glucose level), colon health, weight

management, and energy

RS1 Physically inaccessible starch

starch granules trapped in the food that are prevented from gelatinizing

RS2 Resistant starch granules

indigestible because of their chemical configuration

RS3 Retrograded starch

formed during processing when the heating and subsequent cooling of a starch renders the molecules of amylose and amylopectin inaccessible to enzymatic hydrolysis

RS4 Modified Starch

starches that have been altered to yield a wide variety of modified starches, extending their usefulness in food processing

Pasta

in Italian, means "paste" or "dough

Pasta

Made from flour starch and water

Pasta

Made from semolina, a flour derived from durum wheat.

Couscous

"Moroccan Pasta" made from semolina

that has been cooked, dried, and

pulverized into small, rough particles the

size of rice grains.

High Protein Pasta

Adding soy flour, wheat germ, or dairy products yields high-protein pasta products that contain 20 to 100% more protein than standard pasta.

Flavored

• Vegetable purées made from spinach,

tomatoes, or beets can be added to pasta

to alter its color and flavor.

• Could also incorporate herbs and spices

(e.g. basil, garlic, parsley, and red pepper.

Whole Wheat

Pasta made from whole-wheat flour is slightly higher in nutrients and fiber than standard pasta, but it has a tougher texture and a stronger taste, and tends to

disintegrate if cooked too long.

Asian Noodles

• Often made from flours other than semolina

or farina flour resulting in an often

translucent or clear in appearance.

• Rarely contains egg = imitation noodles

(western term)

• may be made from rice, mung bean, taro,

yam, corn, buckwheat, or potato flours.

• e.g. rice, ramen, soba, and bean thread

noodles

Noodles

If eggs are added (at least 5.5% egg by weight), the pasta product is referred to as noodles, although eggless noodles are available on the market

Pasta Nomenclature

• Pasta or alimentary paste is made by combining water with semolina flour and/or farina flour.

• Prior to drying the pasta, optional ingredients may be added (vegetable puree, etc.)

• Different types of pasta vary not only in shape, but also in ingredients used.

5.5

If eggs are added (at least _______% egg by weight), the pasta product is referred to as noodles, although eggless noodles are available on the market

Spaghetti

little strings

Linguine

little tongue

Vermicelli

little worms

Rigatoni

grooved

Fettuccine

little ribbons

Capellini

"little hairs" ("capelli" means hair in Italian)

Cannelloni

"large reeds" ("canna" means reed; cannelloni are large tube pasta)

Tortellini

"little cakes" or "little pies" (diminutive of "torta" meaning cake or pie)

Lasagna

Likely from Greek "lasanon," a cooking pot, adopted in Latin as "lasanum"; refers to the pasta or the baked dish

Ravioli

Possibly from "riavvolgere," meaning to wrap or enclose

Macaroni

Origin uncertain, but possibly from Greek "makaria," a kind of barley broth, or "makar," meaning blessed or happy

Wonton wrappers

Thin dough wrappers, from Chinese cuisine, used for making wontons