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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!
Name That Starch or Grain Term!
I am the building block of a starch – also known as a monosaccharide
Name That Starch or Grain Term!
I am the starch that has the highest amount of amylopectin – I provide
the most thickening properties
Name That Starch or Grain Term!
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
Name That Starch or Grain Term!
I am the process which takes place on the cooling of the starch paste following gelatinization
Name That Starch or Grain Term!
I am a mixture of fat & flour cooked together
Name That Starch or Grain Term!
Grits are made from me
Name That Starch or Grain Term!
I am a basic dish produced when a cereal grain is browned in a small amount of
hot fat before cooking it in water
Name That Starch or Grain Term!
I am produced by crossbreeding rye and wheat
Name That Starch or Grain Term!
When a starch has been _________, instant cereals can be prepared very quickly, simply by adding hot water
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