All about Eggs!
Q1. Label the parts of the egg.
Q2. Research the role of each of the
following parts of an egg. Also research the
chemical properties of the yolk, albumen
and shell.
yolk
__________________________________
__________________________________
__________________________________
__________________________________
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Vitelline membrane
__________________________________
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albumen (thick and thin)
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shell
___________________________________________________________________________________
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air cell
___________________________________________________________________________________
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chalaza cord
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germinal disc
___________________________________________________________________________________
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shell membrane
___________________________________________________________________________________
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Q3 Research the answers to these different types of eggs.
Which large Australian bird lays big, green eggs?
Which bird lays a pale blue egg?
Which bird lays the smallest egg?
Which New Zealand bird, about the size of a chicken, lays an egg six times
the size of a chicken egg?
Q4 Explain what happens to the air cell as the egg gets older?
___________________________________________________________________________
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Q5 How do the yolk and the egg white change as the egg gets older?
___________________________________________________________________________
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Q6 Complete the drawing to show a fresh egg in the bowl of water.
As the egg gets older the air cell gets _________
causing the egg to ____________ in a bowl of
water however, thin or cracked shells will also
cause the egg to rise slightly.
Q7 Other than placing an egg in a bowl of water, what are two other ways that the freshness of eggs can be
tested?_____________________________________________________________________________
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Q8 Describe how eggs should be stored to retain optimum freshness.
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Q9 Eggs contain proteins, which are made up of chains of amino acids. The characteristics and properties of
proteins are determined by the sequence of the amino acids. Applying heat to proteins can cause the protein
chains to uncoil and change shape. This change is a chemical process that cannot be reversed and its name is
D_________________________.
Q10. As in meats, when heat is applied for a longer time, the protein strands will entrap liquid and a gel will
form. This process is called C___________________________. The temperature that egg yolks
C________________ is ______degrees. The temperature that egg white C___________________ is
_____degrees. This is how you can have soft boiled eggs or ‘sunny side up’. The temperature of
C_____________________ also depends on the presence of other ingredients; adding _______________
and __________________will increase the temperature of C________________, whereas the addition of
______________ or ______________ decreases it. Lowering the temperature is useful in poaching eggs as
the proteins become less stable in the lower __ and are quicker to denture giving a rounded rather than ragged
appearance. Likewise, when beating egg whites to make a meringue, a small amount of __________ such as
cream of tartar or vinegar can be added to ________________ the meringue. When egg whites are beaten,
the protein is _______________, creating a foam that aerates the mixture as it stretches and traps in air
bubbles. The addition of ________ may also help to create a more stiff foam. If using eggs to make a set
custard such as ______________ or a custard base for an _____ __________, it relies on gentle cooking
so that the eggs _______________ evenly within a temperature range of 65 and 70 degrees. Preparing the
custard in a _______________ or cooking in a ____________________ helps to prevent the delicate
mixtures from ___________ or separating. If the custard is overheated the _____________ from the egg
and milk begin to over-coagulate to form small lumps and cause a loss of the smooth, rich texture.
Read your textbook pages 61-62 and complete understanding the text questions 11-20.
Read your textbook pages 83-86 and complete understanding the text questions 21-24
Properties of Eggs
Eggs are an extremely important ingredient in many recipes and have a number of functional roles.
Either complete this template or use the A3 paper to create a ‘functional egg poster’ for your study
Q1. For each of the functions below;
• explain the role of the egg.
• name two food examples where the egg performs this function.