CHAPTER 11: EGGS AND EGG PRODUCERS Flashcards
Why do nearly all baked goods contain eggs?
Their versatility.
Today, most eggs come from where?
Companies that have flocks of 75,000 hens or more, with some companies having as many as 5,000,000 or more.
The average hen lays how many eggs per year?
250 to 300, over twice as many as 50 years ago.
Why are hens laying twice as many eggs?
Improvement of breeding, nutrition, housing, and management practices.
Egg have 6 distinct parts. Name them.
Thin white, thick white, yolk, shell, air cell, and chalazae.
About two thirds of the weight of the edible part of an egg is what?
Egg white, about 1/3 is yolk.
Overall, most of the whole egg is what?
Moisture, with smaller amounts of protein, fat, and emulsifiers.
How are the thick and thin whites layered?
Thin white has two layers. First is just below the shell, the other is between the thick white and yolk.
Another name for egg white is what?
Egg albumen
Other than small amounts of ____ ______ and ______, egg whites consist entirely of protein and water.
mineral ash, glucose
While the special mix of proteins in egg white is extremely important to its functionality, egg white is actually mostly what? What %?
Water, about 90% and only 10% protein.
Compared to yolk, egg white has a very little what?
Flavor and color.
What happens to thick egg white as the egg ages? What does this do to foams?
It thins as the egg ages. As it thins, egg white loses its ability to form foams that are stable.
Egg yolks are about half ____ and half ____ ______.
moisture, yolk solids
As eggs age, yolks pick up what?
Additional moisture from the white.
What happens when the yolk picks up additional moisture from the white?
The yolk thins out and flattens when the egg is cracked into a smooth surface.
The yolk has a protective membrane that ______ as it ages. This makes it more difficult to what?
weakens, separate the yolk from the white.
What does a weak yolk membrane mean for bacteria?
It can easily pass through and multiply if eggs aren’t kept cold.
The solids in yolks consist of what?
Proteins, fats, and emulsifiers, with a small amount of mineral ash and yellow-oragnce carotenoids.
Are egg yolk proteins the same as egg white proteins? Explain.
No, many egg yolk proteins are lipoproteins, proteins bound to fats and emulsifiers, which are both lipids.
% of moisture, protein, fat and emulsifiers, and other (sugars and ash) in whole egg.
moisture: 76%
protein: 12%
fat and emulsifiers: 10%
other (sugars and ash): 2%
% of moisture, protein, fat and emulsifiers, and other (sugars and ash) in egg white.
moisture: 88%
protein: 10%
fat and emulsifiers: 0%
other (sugars and ash): 2%
% of moisture, protein, fat and emulsifiers, and other (sugars and ash) in egg yolk.
moisture: 50%
protein: 17%
fat and emulsifiers: 30%
other (sugars and ash): 3%
Egg white is one of the few foods that is naturally what?
Alkaline
Fresh egg whites have a pH approaching what? What about as it ages?
8, and this increases to 9 or 10 as the egg age and loses carbon dioxide.
Does natural alkalinity of egg whites help reduce bacterial growth?
Yes, but should still be cooked or pasteurized before consumption.
Besides egg whites, the only other common alkaline foods ingredients are what?
Baking soda and hard water. Dutch cocoa is also alkaline, but only because it’s treated with an alkali.
is lecithin a single substance?
No, it’s a complex mixture of emulsifying lipids widely found in nature.
Besides egg yolks, is lecithin found in other dairy ingredients? Anything else.
Yes, and cereal grains, and soybeans.
Is lecithin also sold as a single product?
Yes, as a dark, oily liquid, or sometimes as powder or granules.
The emulsifying lipids in lecithin are classified as what?
Phospholipids
Do phospholipids molecules look somewhat like triglyceride molecules?
Yes
Phospholipids consists of two fatty acids attached to a what?
Glycerol
Instead of a third fatty acid (like triglycerides), phospholipids contain what?
So-called phosphate group.
What are the fatty acids and phosphate group attracted to?
The fatty acids are attracted to fats and oils (lipids) in food, while the phosphate group is attracted to water.
What allows phospholipids such as lecithin to acts as emulsifiers.
Its the ability to attract both water and lipids that allows phospholipids such as lecithin to acts as emulsifiers.
The most well-known emulsifier in egg yolk.
Lecithin
How much lecithin does egg yolk contain?
10%
Like most lipids in egg yolks, lecithin is bound to what?
Lipoproteins
The emulsifying lipoproteins provide many functions in food, but most notably what?
Most notably bonding to both water and oil. By bonding to both, emulsifiers and emulsifying lipoproteins hold together, or bind, complex mixtures of ingredients, such as cake batters.
An important factor in the color of egg yolk is what? Explain.
Hen’s feed. The more carotenoids in the feed, the more yellow-0range the yolk.
Wheat, oat, and white corn produce what types of yolks?
Lighter yolks.
Alfalfa and yellow corn produce what types of yolks.
both high in carotenoids, produce deeply colored yolks.
When feed is naturally low in carotenoids, what can be added for color?
Marigold petals, which are a rich source of carotenoids.
Does the hen’s feed also affect the flavor of egg yolks?
Yes, this explains why some brands of eggs taste different than others.
What is sometimes added to hen feed so that hens are high in this healthful oil?
Omega-3-fatty acids. These eggs will have a different flavor than regular eggs.
Eggshell represents how much of the egg’s weight?
11%
Although it serves as a hard protective covering, eggshells are what? What does this mean?
Porous. This means that odors penetrate eggshells, and moisture and gases (primarily carbon dioxide) can escape.
In commercial practice, what is done to eggs for cleanliness?
Washed and sanitized to remove dirt and reduce likelihood of salmonella contamination. They are also lightly coated with mineral oil to delay moisture loss.
The use of organic eggs more than double when?
During the 1990s and continues to grow at an annual rate of 15% per year.
In response to growing popularity of organic eggs, the US initiated what program?
National Organic Program in 2002 to unify the use of the term organic across the country.
Organic growers must be ______, or they cannot use the term organic to describe their products.
certified
Organic eggs come from animals that are given no what?
Antibiotics or growth hormones.
Organic hens are fed what?
Organic feed, which is produced without using most pesticides, synthetic fertilizers, irradiation, or genetic engineering.
Before a product can be labeled organic, who inspects the farm?
A government-approved certifier inspects the farm where the food is grown to make sure the farmer is following all the rules necessary to meet USDA organic standards.
Is the safety or nutritional value of organic eggs different from standard?
Not necessarily.
White type of hens lay white eggs?
Hens with white feathers and white earlobes.
What type of hens lay brown eggs?
Hens with red feathers and red lobes.
What % of commercial breeds produce white eggs?
95%, but hens bred in parts of New England produce brown shells.
Does shell color affect flavor, nutrition or functionality of egg?
No
Eggs contain _____ protective membranes between the shell and white.
2
Soon after an egg is laid, an ___ ____ forms between the membranes at the eggs ______ end.
air cell, larger
As an egg ages, loses moisture, and shrinks, what happens to the air pocket?
Increases in size. This is why old eggs float in water while fresh ones sink.
What are the chalazae?
Twisted white chords that hold the yolk to the center of the egg.
What happens to the chalazae as an egg ages?
They disintegrate.
Chelsea are an extension of the ____ _____ and are completely ______. Although pastry chefs typically use a chinois or sieve to strain them from certain products, such as custards.
egg white, edible
What are shell eggs?
Eggs purchased in their shells, either by the dozen or in flats.
One flat holds how many eggs?
2 1/2 dozen or 30 eggs.
How many flats are in a case?
12 flats in a case, which means that one case contains 30 dozen or 360 eggs.
Shell eggs are sometimes called what?
Fresh eggs
Are shell eggs always fresh?
No, they might be several weeks or months old.
Shell eggs are sorted and classified according to ______ (quality) and ______.
grade, size
What is AAFC?
Agriculture and Agri Food Canada
USDA and AAFC offer programs to classify and label eggs but which is voluntary and which is mandatory?
US is voluntary, Canada mandatory.
What % of eggs sold in the US are graded by USDA?
30%
The three USDA grades for acceptable shell eggs are what?
Grades AA, A, and B.
Canada has to acceptable grades, what are they?
A and B.
Do quality grades reflect product safety or nutritional quality?
No, and grade B eggs–stored properly–are safe and will have the same nutritional value as high quality.
Usually, USDA graded eggs are washed, packed, and graded within how long?
A day to a week of being laid, but they can be legally graded for up to 30 days.
Do USDA graded eggs have to be labeled with the date that they were packed and graded?
Yes
The sell-by date (also on the package) is defined as no more than ____ days from the time the eggs were packed and graded.
30
Most common eggs purchased in a bakeshop?
Grades AA and A
Main difference between USDA AA and A eggs is what?
The firmness of the white and the size of the air cell. Only eggs with the firmest whites and smallest air cells can be labeled USDA Grade AA.
Why are firm white and yolks particularly important? When are they less important.
Because they hold their shape when frying or poaching an egg. They are less important for baking.
Prior to 1998, eggs that were nearing their expiration date could be returned to the packer to be what?
Washed, packed, and graded a second time, extending their usable life. This is no longer allowed in the US for safety reasons.
Grade B eggs might have one or more of the following defects.
Stained shells, large air cells, watery whites, small blood spots in the white, or enlarged, flattened yolk.
Are Grade B eggs acceptable for general baking?
Yes
Do Grade B eggs make good meringues?
Their whites may not while properly if they’re watery.
Does the quality of eggs reflect age?
No, but quality does decline over time.
Will properly refrigerated eggs still lose their Grade AA status? How long does it take?
Yes, they can be downgraded to Grade A in little as a week. In 5 weeks, they will go from A to B, as whites thin and air cells enlarge.
Does nutrition value decline quickly as Grade?
No, properly handled eggs will maintain their nutritional value and wholesomeness for quite some time.
Are size classifications for eggs different from quality classifications?
Yes
How many size classifications are there in North America?
6, all based on minimum weights per dozen; it does not refer to dimensions of an egg or how large it is.
The most common size classification for eggs used in a bakeshop.
Large, extra large, and jumbo.
What are the 6 size classifications?
Jumbo, extra large, large, medium, small, peewee.
How are eggs graded for quality?
Candling is the primary method used.
What does candling do?
A bright light passes through the egg and exposes the size of its air pocket, thickness and clarity of the white, the position and stability of the yolk, the presence of blood spots or a developing embryo, and more.
When a formula calls for a certain number of eggs, what should you assume?
It’s based on large-sized eggs, with the edible portion weighing approximately 1.75 ounces (50 grams).
How much of an egg is white and yolk?
2/3 is white and 1/3 is yolk.
If a formula calls for 3 extra large eggs, how do you determine weight?
3 x 1.75 (3 x 50g) or 5.25oz (150g).
If a formula calls for 3 egg yolks, how do you determine weight?
3 x 0.55oz (17g), or 1.65 ounces (50 grams).
If a formula calls for 3 egg whites, how do you determine weight?
3 x 1.2oz (33g), or 3.6oz (100g)
Why do individual eggs in a carton still vary in weight?
Because size classifications are determined by minimum weights of an entire dozen.
Egg products include various forms of what?
Eggs that are sold removed from their shells.
The range of egg products includes what?
Egg whites, egg yolks, and whole egg products refrigerated, frozen, or dried.
Liquid and dry egg products have been available for how long?
The late 1800s, but quality was generally poor. Today, 1/3 of eggs used in the US are egg products.
Why can most egg products be used in place of eggs in most bakeshops today?
Because changes in processing have improved over the years.
Does the viscosity of frozen products change over time?
Yes, but this does not affect their properties.
Are egg products steadily replacing shell eggs in the bakeshop? What 2 main reasons?
Yes, the main one being safety. By law, egg products must be pasteurized so they are free from salmonella bacteria. Also, it saves money on labor.
Frozen egg whites often contain what? Why?
Added thickener, such as guar gum. Whipping agents–such as triethyl citrate or sodium lauryl sulfate–are also added, sometimes.
What does guar gum do for frozen egg whites?
This protects it from ice crystal damage. It also increases viscosity. improving the ability of frozen whites to foam.
What do triethyl citrate or sodium lauryl sulfate do for frozen egg whites?
Whip up higher and faster than whites from the shell.
How many eggs can be broken in an automated egg breaking machine?
162,000 eggs per hour or 45 eggs per second. Info provided by the American Egg Board.
Why are higher amounts of heat desired when pasteurizing foods?
With most foods, high pasteurization temperatures mean shorter heating time inflicts less quality damage to the food.
Why can’t eggs be pasteurized at high temperatures?
Egg proteins will coagulate.
A typical commercial pasteurization process for liquid whole eggs is what?
Heat eggs for 3.5 minutes at 140ºF (60ºC).
Can dry egg white be pasteurized a different way?
Yes, they can be held at 130ºF (54ºC) for 7 days.
Does pasteurization affect the properties of eggs?
For the most part, no.
Advantages of egg products.
Safety, reduced labor, take up less space, no loss due to breakage, longer shelf life (as long as remaining dry or frozen), no leftovers, uniformity in quality.
What applications do frozen egg whites not work well on? Why? How can you alter this?
Swiss meringues, because frozen egg whites do not form as firm or stable a foam as whites from fresh shell eggs. Fresh or dried whites can be blended with frozen whites to assure better whipping.
Can frozen egg whites be used inmost applications?
Yes
What happens to thick and thin egg whites when unthawed?
They may separate, so shake container well.
Frozen yolks usually contain what? How much is added?
Added sugar or glucose corn syrup, generally 10%.
