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1. use the Science of Foods terminology in relation to discussing foods or food products.
   
2. use the chemistry and composition of foods to explain how it relates to the quality of a food product.
   
3. discuss and problem-solve how preprocessing and preparation procedures impact food quality.
   
4. utilize value-added products to develop unique quality products.
   

The basic ingredients of baked products are usually flour and liquid. Fat, sugar, salt, eggs, leavening agents and flavorings are other common ingredients which may or may not be used in the recipe, depending on the product desired. Each one of these ingredients has its own role and function in baked products. The role(s) will vary somewhat from one type of batter or dough to another.

Liquid in a product may be milk, water, orange juice and any others. Although these liquids in the baked product may function differently, generally, liquid serves as a solvent for salt, sugar and other solutes. It also assists in the dispersion of all the colloids and suspensions, in the development of gluten, and contributes to both the leavening and gelatinization phenomena during baking.

In addition to sweetening baked products, sugar facilitates air incorporation by shortening. It also inhibits development of gluten and gelatinization of starch and elevates the temperature at which egg and flour proteins heat denature.

Eggs contribute to the structure of a baked product. They may serve to do this through their contribution of heat denatured proteins, steam for leavening or moisture for starch gelatinization. Egg yolk is also a rich source of emulsifying agents and, thus, facilitates the incorporation of air, inhibits starch gelatinization and contributes to flavor.

The leavening source used in a baked product may serve to produce gas by physical, chemical or biological methods. The leavening selected is usually dependent on the balance and kind of ingredients in the formula, and the manipulation methods used. Salt and a wide variety of flavorings are used to obtain the type and variety of product wanted. In addition to being used as a flavoring, salt functions to control yeast metabolism in yeast bread.

	FLOUR Flour contributes protein and starch to a baked products structure, the protein primarily being gluten. Flour may contribute protein and sugar for the Maillard reaction and/or yeast food for biological leavening. Flour also contains enzymes which may serve to weaken the structure.
	LIQUID Liquids will serve as tougheners. They will enhance the development of gluten and/or facilitate the gelatiniztion of starch, thus, contributing to structure. Additionally, liquid serves as a solvent, it may also act as a leavener, contribute to chemical reactions, and/or as a dispersing agent. If it is an appropriate type of liquid, such as milk, it may contribute to the Maillard reaction. Milk and water, fruit juices, and potato water contribute in different ways to the quality of a baked product.
	FATS Shortening, fat or oil contribute to the tenderization of baked products through inhibition of gluten development and starch gelatinization. They do this through a water-proofing effect, possibly due to the complexing with the carbohydrate and/or protein. Fat can help leaven a product due to incorporation of air. The extent of each role fat will play is dependent on the fat composition. For example, butter or margarine contains water and so are not as great a tenderizer as pure fat. Additionally, butter may contain some sugar and protein in the milk solids and so contribute to the Maillard Reaction. Of course, triglyceride fatty acid composition influences fat plasticity and its ultimate function.
	SUGAR Sugar contributes to the tenderization of the product due to inhibition of gluten development, "peptization" of gluten and/or inhibition of starch gelatinization. It does this primarily through its competition for water. Additionally, sugar may inhibit denaturation of the egg and flour protein. Sugar serves a number of other roles, such as enhancing the Maillard Reaction. It may also serve as a substrate, making yeast in the fermentation for leavening in bread.
	LEAVENING AGENTS Leavening action in a baked product may be due to chemical leavening, biological leavening and/or mechanical leavening. Mechanical leavening is generally added as a beaten aerated product or a steam leavened product. Air can be incorporated by beating eggs, sifting flour, beating batters or folding and rolling doughs. The additional leavening action by chemical means is produced in a baked product by mixing an acid reactant material and sodium bicarbonate. This acid reacting material is varied to produce the type of reaction desired in a baked product. These different acids each have their unique characteristic dependent on a range of environmental conditions and stresses.
	EGGS Eggs may contribute liquid to a product and thus serve as a toughener. It is a toughener partially due to its contribution to gelatinization of starch and/or development of gluten. The egg white portion appears to be particularly effective as a toughener. Actually, the yolk serves as a tenderizer, probably due to its fat content. The yolk may also function to emulsify fat due to its lecithin content. This is a crucial function in cream puffs. Eggs also contribute to leavening action through the emulsification of fat and air incorporation, foaming action and/or through the contribution of water to steam.
Roles Listing Summary

In reviewing the roles of ingredients, it is important to consider how the ingredients are balanced. In addition to the liquid versus dry ingredients, it is important to also balance the tougheners and tenderizers or structural enhancers or structural inhibitors. There are as follows:

Toughener Structural Enhancer	Tenderizer Structural Inhibitor
flour	fat
egg	sugar
egg white	egg yolk
water	acid
milk

Mixing is an important factor in producing any baked product. The blades themselves will make a difference. These influence viscosity, degree of dispersion, air incorporation and other quality characteristics.

Specifically, just reviewing the effect of mixing or agitation on flour itself, the following will occur. The flour, made up of chunks of protein, starch and starch granule protein can be mixed with water. The mixing action will serve to physically break apart the protein chunks into smaller parts and expose the hydrophilic portion of the proteins. The actual impact can be reviewed within the gluten theory portion of this site.

General objectives in mixing batters and doughs are as follows: The objectives of mixing can be listed as follows:

uniform distribution of ingredients minimum loss of the leavening agent optimum blending to produce characteristic textures optimum development of gluten for various products

What is optimum dispersion, optimum minimum loss of leavening agent, optimum blending and gluten development is dependent upon the product. There are a lot of different mixing methods and beating utensils.

Each method will serve to prepare a product of particular quality characteristics and/or is adaptable to particular ingredients and/or conditions.

An understanding of the function and role of ingredients in any flour mixture necessitates an understanding of generalities and then of specifics. The proportion of tenderizers to tougheners is a relatively simple way to classify flour types. There are two major categories: batter and dough systems. Batter System have relatively high water content to flour. Water is the continuous. Structure depends much less on gluten development than on gelatinization of starch. Dough System gluten matrix is the continuous phase. The matrix consists of membranes surrounding the gas cells and is continuous because the cells are in contact with each other.

Classification of Batters and Doughs

TYPE	LIQUID	FLOUR
pour batter		1	1
drop batter		1	2
soft dough		1	3
stiff dough		1	4

In the past, batters and doughs were classified on the basis of the proportion of liquid to flour (by weight). This would reflect the probable liquid. This classification, to some extent, still fits with basic household ingredients. However, as more effective mixing and homogenizing methods have been developed and as a number of additives have been included for formulations, the proportion of liquid and flour does not always reflect the actually viscosity. The addition of emulsifiers will permit the increased incorporation of air and increase the viscosity. The addition of vegetable gums will also enhance the viscosity. All of these mean that viscosity and elasticity are not necessarily a reflection of the liquid to dry ingredients. A number of factors other than proportion of liquid to flour that influence batters and doughs can be listed:

concentration of other ingredients type or kind of ingredients temperature of ingredients size and shape of mixing bowl type of mixing ingredients kind and method of manipulation

GENERALIZATIONS IN REGARD TO INGREDIENT PROPORTION IN A CHEMICALLY LEAVENED BAKED PRODUCT

A definite relationship exists between the fat, sugar, liquid, flour, and baking powder,

A substantial increase in fat and/or sugar should be balanced by an ingredient action which will serve to toughen the batter,

A substantial increase in fat and egg means a decrease in liquid,

A substantial increase in eggs means a decrease in the amount of liquid and baking powder,

What does the above diagram represent?

During baking of any baked products there is an important interrelationship between the leavening, the balance of tenderizers and tougheners, resulting structural components, and the temperature. For example if one has a "tough" product, with high development of gluten, one wants to have the strong slow evolving of carbon dioxide and ethanol from yeast. In contrast, a popover is a tender product. Most of its structure comes from egg and gelatinized starch. A high temperature produces steam, maintain its production of steam until the structure is set.

Process

• melting of fat
• increased fluidity of batter/dough
• increased dissolving of solutes
• chemical or physical or biological leavening
• denaturation of protein
• gelatinization of starch
• steam leavening
• Maillard reaction

Baking of different flour mixtures brings about a delicate balance between the firming of structure, the leavening action, and the development of optimum flavors and colors. The particular heating process, as with the selection and proportion of ingredients, is specific for each formula. Typical baking temperatures are available for various baked products.

A brief review of baked products should probably incorporate those pour batters which are mechanically leavened cream puffs. With cream puffs, eggs are an important constituent serving to both contribute leavening with water, emulsify the high percentage of fat, as well as contributing to structure. Both the egg protein and wheat starch are the primary structural components. Popovers also have equal parts of flour and liquid formulating a pour batter. Again, egg and starch are the primary structural components. Another mechanical steam leavened products is pastry. In mixing a pastry product the incorporation of fat is critical. Finely mixed fat and flour will make a more mealy pastry, whereas, a coarsely mixed flour/fat formula will likely make a more flaky pastry.

GLOSSARY

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active dry yeast
all-purpose flour
amylase
bake
bake
Baker's yeast
baking powder
batter bread
batter systems
beat
blend
bread flour
break and shred
brown sugar
buckwheat
cane sugar
carbon dioxide
carotenoid pigments
compressed yeast
corn syrup
cream of tartar
crumb
cut
cut and fold
denaturation
dextrose
diacetyl
disulfide
disulfide linkages
dough systems
eggs
emulsifier
emulsion
enriched flours
fermentation
fermentation lock
gliadin
glucose
gluten
grain size
grind
hard wheat
instant yeast
invert sugar
knead
lard
leavener
light rye flour
lipase
lipids
lipoproteins
liquid
liquid sugars
maillard reaction
maltase
maltodextrins
maltose
maturing agent
mill
millet
molasses
monoglyceride
muffin
oligosaccharide
oven spring
overproof
pan
pentose
peptide linkage
plastic
plasticity
potassium bromate
pro-oxidant
proofing
proofing yeast
protease
pumpernickel flour
quick bread
quick-rise yeast
rapidmix yeast
rapid rise yeast
rise
rye flour
shred
soft wheat
sponge
spores
stabilizer
straight dough
staling
sugar
tenderizer
total sugars
toughener
traditional active dry yeast
unbleached flour
underproof
unleavened
white rye
whole wheat
yeast
yeast bread
yeast fermentation