Starch and Grains
What is the ration of flour to liquid in cream soups?
1 Tbsp of flour : 1 cup of liquid
What is the breakdown of starches in heat?
1. Polysaccharides 2. Dextrins 3. Oligosaccharides 4. Disaccharides 5. Monosaccharides
What are the 5/6 mother sauces?
1. White sauce- fat, flour, liquid, and seasonings 2. Bechamel - when milk based 3. Veloute - light stock of veal, chicken, or fish 4. Espagnole - brown stock of beef or pork 5. Hollandaise - egg yolks and white wine vinegar 6. Tomato - tomatoes and vegetable stock
Endosperm
Longest part of the kernel, used as flour
What characteristics do cross linked or cross-bonded have?
Lower viscosity (amylopectin) Increased temperature for hydration Increased stability in acid conditions Increased resistance to shear or stirring Increased tolerance to heat
What is hydrolysis?
Mixing starch with water and an acid to break molecular chains "Thin boiling" or "acid thinned" starch Low viscosity
How does sugar affect a starch paste?
Raises temperature of gelatinization Can decrease gel strength in starch pastes Competes for water
How does being undercooked affect starch paste?
Raw starch flavor Less smooth and silky mouth feel
Disaccharides are
any of a group of carbohydrates, as sucrose or lactose, that yield monosaccharides on hydrolysis. (Also called a double sugar)
Rice Starch
forms a weak gel
Durum wheat
hard wheat for making macaroni and pasta Semolina-purified middlings of durum wheat that have been ground to a certain sieve size
Describe Starch Gelantinization
is the process of breaking down the intermolecular bonds of starch molecules in the presence of water and heat, allowing the hydrogen bonding sites to engage more water. This dissolves the starch granule in water and causes swelling.
Arrowroot
used more in European cooking, brownish paste
Tapioca
starch paste is stringy
Glycogen
storage form of glucose
What is meant by retrogradation of a starch paste?
-Retrogradation refers to the reassociation of starch molecules after a its initial mixture cools. -It is responsible for defects in starchy foods such as the loss of viscosity in soups and the staling of bread.
What is a modified starch?
A chemical or physical means is used to improve function in food preparation
What is "wet milling"?
A process that chemically modifies starch. This enhances desirable qualities
Fiber
A tough complex carbohydrate that the body cannot digest
Sorghum
A type of millet with large seeds, not used in the U.S but an important grain crop in the world
What is a hydrocolloid?
A water loving substance
What is retrogradation?
After gel formation, changes in the structure continue and bonds tighten and gel weeps
What digestive enzyme breaks down starch?
Amylase- breaks polysaccharides to disaccharide "maltose" to monosaccharide "glucose"
What are the 2 types of starch molecules?
Amylose and Amylopectin
Enrichment
An enriched food is a product to which nutrients have been added. Typically, the added nutrients were present in the food in its original form, but were removed at some point during processing. White bread is an example of an enriched food because certain vitamins are added after the bleaching process depletes them.
What is the effect of moist heat on starches?
As heated, starch granules absorb water and swell Increased viscosity Increased translucency (gelatinization) Different starches gel at different temperatures Complete at 190-194 degrees F.
How do you make a roux?
Blend melted fat with flour to form paste
What is amylopectin?
Branched, bushy structure starch Provides cohesion or thickening properties when cooked in liquid DOES NOT produce a gel Glucose is basic building block
Rice
Brown Rice: the whole kernel w/only the outer husk removed, crunchy, slightly nutty flavor, take a long time to cook Converted Rice: B vitamins and minerals in the bran and hull dissolve and migrate to the endosperm so the nutritional content of the final product is enhanced, parboiled grain before processing Quick-Cooking Rice: precooked to gelatinize the starch and then dried, has a tendency to congeal Rice Flour: made from ground white or brown rice, has no gluten, good for people with allergies to wheat flour Waxy Rice Flour: almost entirely amylopectin, therefore, an excellent stabilizer and prevents seperation of sauces and gravies in frozen foods
What type of roux has less thickening power?
Brown roux
Cellulose
Carbohydrate component of plant cell walls. It's insoluble
What types of food contain amylopectin?
Certain strands of corn, rice, grain, sorghum, and barley
What kind of flavors can be added to a starch thickened dessert?
Chocolate, cocoa, coconut, nuts, maple syrup, diced fruits, etc
What does it meant to temper an egg?
Continuously adding hot liquid into eggs while whisking. Keeps the eggs from scrambling in dishes
Maillard reaction
Contributes to the appearance, flavors and aromas in baked goods, etc.. reaction of a reducing sugar and an amino acid
What are types food contain amylose?
Corn, wheat, rice, tapioca contain 16-25%
What kind of starch is used in gravies and stir-fry sauces?
Cornstarch- more clear and glossy 1 tbsp per cup of liquid
How do fats and proteins affect a starch paste?
Delay hydration Lowers rate of viscosity development
What are native starches?
Derived from plants without chemical or physical modifications Ex. cornstarch
What are the effects of dry heat on starch?
Dextrinization Starch becomes brown and toasted flavor develops More soluble Reduced thickening Ex. brown roux
When should you stir a starch paste?
Early in cooking
Fortification
Food fortification - also known as food enrichment - is when nutrients are added to food at higher levels than what the original food provides. This is done to address micronutrient deficiencies across populations, countries and regions.
Millet
General name for numerous small seed grasses Used to make porridge, unleavened bread, beer
What is sucrose?
Glucose + Fructose
What is lactose?
Glucose + Galactose
What is maltose?
Glucose + Glucose
Fiber whole grains
Good source of soluble fiber (helps lower cholesterol & control blood sugars) and insoluble fiber decreases risk of colon cancer
Germ
Good source of vitamins, minerals, fats, sugar protein
Nutritive value
Grains 71% CHO Protein 11% Fiber 2-3% Minerals, some vitamins 2%
What are the characteristics of "thin boiled" starch?
Has low ______ Hydrates at a lower temperature Still retains its gelling properties (amylose) Often used in confectionary industry
Amaranth
High in lysine (limiting amino acid in other grains) Can be incorporated into bakery products if mixed (1:3) with wheat flour
In the food industry starch is purified into a _____?
Hydrocolloid
How does aggitation or stirring affect starch paste?
If excessive can rupture starch molecules Decreases viscosity Slick, pasty mouth feel
Where are pectins used?
In jellies
What is a dextrin in starch?
Is a group of low molecular weight carbohydrates produced by the hydrolysis of starch. They are widely used in industries due to their nontoxicity. To become dextrin, the starch is subjected to a hydrolysis process that divides the long molecular chains of starch
Describe cornstarch pudding
Less pasty and smoother mouth feel than flour
What is amylose?
Long chainlike starch molecules Provide gelling characteristic Colloidal dispersion holds shape Glucose's basic building block
What is an example of moist heat on a starch?
Oatmeal, cream of wheat, grits, rice
Buckwheat
Pancake flour
Hemicellulose and mucilages
Partially soluble
What comes after gelatinization?
Pasting
Barley
Pearl Barley: hull and bran removed from the whole grain, used in soups, baby foods
complex carbohydrates
Polysaccharides
What is instant starch?
Pre-cooked or pre-gelatinized starch Cooked or dried into granules Needs hot water to disperse and stirring to prevent lumps Has stability and smooth texture Instant puddings, gravies, and sauces
What are cross-linked or cross-bonded starches?
Produced by reagents such as phosphorus oxychloride Welds starch chains together to limit swelling
Where is starch stored?
Roots Seeds Fruits Stems of plants
Does a roux or slurry have a richer flavor?
Roux
Roux or slurry more stable?
Roux
Dextrin is like toast
Shortened starch (darkening process)
Pectins
Soluble
What is an example of a cross linked or cross-bonded starch?
Spaghetti sauces Pie fillings for frozen pies
What is heat treated starch?
Special process Labeled as starch (instead of modified starch) because no chemicals are involved Greater viscosity and stability
What are starches used as?
Stabilizers Texturizers Thickeners Binders
How do you make a slurry?
Starch (flour or cornstarch) mixed with cold liquid Has the consistancy of thick cream Added to hot liquid while stirring and then cooked over direct heat until mixture boils
Caramelization
Sugar browning (sugars heated over their melting point)
What is cold water starch?
Swells at room temperature water
Separation or "weeping" of liquid from a gel
Syneresis
What is syneresis? Why may it occur in cooked starch mixtures?
Syneresis, also known as weeping, is the result of an increase in molecular association as a starch mixture ages.
What factors affect starch paste?
Temperature and time of heating If undercooked Agitation or stirring Acidity Sugar Fats and proteins
Invert sugar
The mixture of fructose and glucose (like in candy)
How are starch thickened desserts prepared?
Thicken liquid with starch before adding egg Add small amount of egg mixture to egg to dilute or temper the egg to prevent coagulation Then add bulk of mixture Cool mixture after addition of the egg to coagulate the egg proteins Should not reach boiling
How does temperature and time of heating affect starch paste?
Thicker if cooked quickly Bring to a boil over direct heat, constantly stirring until sauce thickens and simmer 1 minute Ex. white sauces
Why do we need to modify starches?
To achieve a desired texture and flavor in a product that must undergo higher temperatures, high shear, low pH, or freeze-thaw cycles during production
When does the gel form in gelatinization?
Upon cooling
Rye
Used mainly for the commercial manufacture of bread Very distinct flavor Breads made with rye flour are moist and less elastic in texture, rye bread is frequently made of a combination of wheat and rye flours
Oats
Whole grain is inedible-outer husk touch and fibrous Rolled Oats-take the longest to cook Oat Bran-the outermost part of the pericarp and has been shown to decrease serum cholesterol
Monosaccharides
a carbohydrate that does not hydrolyze, as glucose, fructose, or ribose, occurring naturally or obtained by the hydrolysis of glycosides or polysaccharides.
What is a polysaccharide
a carbohydrate, as starch, inulin, or cellulose, containing more than three monosaccharide units per molecule, the units being attached to each other in the manner of acetals, and therefore capable of hydrolysis by acids or enzymes to monosaccharides.
Where is starch found?
breads, cereals, grains and potatoes
Simple Sugars
monosaccharides and disaccharides
Flour
most common type in food preparation, gravies, sauces, soups
Corn
next to wheat, the most used grain in the U.S
Starch is a _____
polysaccharide
Cornstarch
regular or waxy, regular forms a gel, puddings, fruit juices. Waxy cornstarch-used commercially for canning and freezing (in amylopectin)