seminar 2 – starch & grain components brook benton, ms, rd, ldn, cde nanna cross, phd, rd, ldn

Seminar 2 – Starch & Grain Components

Brook Benton, MS, RD, LDN, CDENanna Cross, PhD, RD, LDN

Review of Lab 1

Questions regarding Unit 2 lab reports?

A. Starch principles Pages 23-24 in Laboratory ManualFollow instructions for the type and amount of

starch in Table 3.1, page 24.Do ONLY treatment numbers 1, 3, 5, 7 & 8 and

describe firmness and appearance in the table.Answer questions 1-5, page 24

B. Effect of water temperature on starch dispersion Page 25; answer questions, page 25

Starch

Storage form of carbohydrate

Common sourcesSeeds, roots, tubers

Cereal grains – corn, wheat, rice, oats Legumes Roots and tubers – potato, tapioca, arrowroot

Starch

• Less common sources of starch

• Check out Web Resources within the course

• www.quinoa.net• www.grains.org• www.ilovepasta.org• www.riceland.com

Starch Molecule

Starch is a polysaccharide.

Polysaccharide is made up of hundreds or thousands of glucose molecules.

Polysaccharide – a complex carbohydrate. Glucose – a monosaccharide or simple sugar.

Two Kinds of Starch Molecules

AmyloseLong chainlikeCorn starch and wheat flour

Amylopectin

Branched, bushy structureTapioca has the highest amount of amylopectin

Most starches are a mixture of the two of these in varying degrees

Two Kinds of Starch Molecules

AmyloseProvides gelling characteristicFor example, pudding or cream pie

Amylopectin

Provides cohesion or thickening properties when cooked with liquid

For example, gravy or thickening for fruit pies

Changes in Starch with CookingMoisture – dissolves starchHeat – starch granules swellCooling - retrogradation

Preventing Lumping in Powdery Starches

Before hot liquids are combined with starch, the particles of starch must be separated to bring about a uniform dispersion of well hydrated starch granules

This process can be accomplished in one of three ways before adding hot liquid:

Dispersing the dry starch with melted fat Blending the dry starch with sugarMixing the dry starch with cold water to form a

slurry

Characteristics of Native StarchesNative Starches CharacteristicsCornstarchTapiocaWheat flourPotatoSweet riceArrowroot

*Table 13-2. page 219, Introductory Foods.

Clear glossy sauceTolerates

freezing/thawingOpaque sauceDoesn’t tolerate heatTolerates

freezing/thawingClear glossy sauce;

tolerates high heat and acid

Starch Hydrolysis

Breakdown of starch molecule produces glucose

AmylaseEnzyme that hydrolyzes starch

AcidMay be a catalyst in reaction

Factors that alter gelatinization and gelation

How do each of these factors influence gelatinization or gel formation of starches?

1. Heat?2. Agitation?3. Other ingredients?

1. Acid?2. Sugar?

QUESTIONS???

Cereal Grains

Cereal grains are seeds of the grass family.

Most important cereals used for food:Wheat, corn (maize), rice, oats, rye, barley, millet

Cereal refers to a large group of foods made from grains:Flours, meals, breads, alimentary pastes or pasta

Structure of Whole Grains

Outer bran - high in fiber

Germ - rich in fat and protein

Starchy endosperm - milled white flour comes entirely from the endosperm

Nutritive Value of Cereal Products

Varies depending on the part of the grain that is used and the method of processing.

Enriched flour is white flour with specified B vitamins and iron added.

Cereal CookeryMain purpose: to improve palatability and digestibility

Factors that affect time required to cook include: Size of cereal particle Amount of water used Presence of absence of bran Temperature Method of cooking used

Cooking MethodsGranular Cereals

4 to 5 cups of water to 1 cup of cereal

Rolled Oats2 to 2 ½ cups of water to 1 cup of cereal

RiceTwice the volume in waterBrown rice takes twice as look to cook as white rice

Pasta2 – 3 quarts of boiling water for each 8 ounces of

pastaIncreases to 2 – 2 ½ times its original volume after

cooked

QUESTIONS???

Name That Starch or Grain Term!


I am the building block of a starch – also known as a monosaccharide


I am the starch that has the highest amount of amylopectin – I provide

the most thickening properties


I am the sum of changes that occur in the first stages of heating starch granules in a moist environment - this includes swelling

of granules as water is absorbed and disruption of the organized granule structure


I am the process which takes place on the cooling of the starch paste following gelatinization


I am a mixture of fat & flour cooked together


Grits are made from me


I am a basic dish produced when a cereal grain is browned in a small amount of

hot fat before cooking it in water


I am produced by crossbreeding rye and wheat


When a starch has been _________, instant cereals can be prepared very quickly, simply by adding hot water

seminar 2 – starch & grain components brook benton, ms, rd, ldn, cde nanna cross, phd, rd, ldn

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