Properties Of Sugar Flashcards
List the properties of sugar
8
Solubility Sweetness Ability to assist aeration Maillard reaction Caramelisation Crystallisation Hydrolysis Inversion
Describe the solubility property of sugar
3
Sugar is a white crystalline compound
It is soluble in water
A syrup is formed when a large amount of sugar is dissolved in a small amount of water
Describe sugars physical appearance.
Sugar is a white crystalline compound
What is sugar soluble in?
Water
What forms a syrup?
A syrup is formed when a large amount of sugar is dissolved in a small amount of water
Give a culinary application of the solubility property of sugar
Syrup is used as a preservative in canned fruit e.g. canned peaches
Describe the sweetness property of sugar
4
All sugars are sweet and give an appetising flavour to food
Some sugars are much sweeter than others
This is measured on a point scale of sweetness
Fructose has the highest sweetness rating and lactose has the lowest
How do all sugars taste?
Sweet
What does sugar do to the flavour of food?
Sugar gives food an appetising flavour
How is the sweetness of a sugar measured?
It is measured on a point scale of sweetness
What sugar has the highest sweetness rating?
Fructose
What sugar has the lowest sweetness rating?
Lactose
Give a culinary application of the sweetness property of sugar
(1/2)
Shortbread
Cupcakes
Describe the ability to assist aeration of sugar
4
When sugar is whisked with egg aeration occurs
The sugar helps to denature the egg protein, causing it to unfold and entrap air bubbles
Whisking also creates heat that begins to set the egg albumin
This forms a temporary foam, which will collapse after a while unless it is heated to coagulate and set as a permanent foam
What occurs when sugar is whisked with egg?
Aeration occurs
What two ingredients are needed for aeration to occur?
Egg and sugar must be whisked together
What role does sugar play in aeration?
The sugar helps to denature the egg protein, causing it to unfold and entrap air bubbles
What protein in egg is responsible for aeration?
Egg albumin
What must be done to a temporary foam to make it set?
It must be heated
What is formed when a temporary foam is heated?
A permanent foam
What happens to the structure of protein when a permanent foam is formed?
(5)
The protein chains have unfolded
The unfolded chains have entrapped air bubbles
A temporary foam has been formed
The temporary foam is heated
The protein coagulates to form a permanent foam
Give a culinary application of sugar’s ability to assist aeration
(1/2)
Meringues
Sponges
Describe the caramelisation property of sugar
4
On heating, sugar melts and caramelises
This occurs over ten gradual stages, between 104 degrees and 177 degrees
Caramelisation normally occurs at 160 degrees, resulting in an attractive brown colour and a sweet taste
If overheated (above 177 degrees) caramel will carbonise or burn
What happens to sugar when it is heated?
Sugar melts and caramelises
Over how many stages to caramelisation occur?
Over ten stages
Between what temperature range does the ten stages of sugar melting occur?
104 degrees and 177 degrees
At what temperature does caramelisation occur?
At 160 degrees
Describe caramel.
It has an attractive brown colour and a sweet taste
At what temperature does caramel burn?
177 degrees
What happens to sugar if it is heated to 104 degrees?
It melts
What happens to sugar if it is heated to 160 degrees?
It caramelises
What happens to sugar if it is heated to 177 degrees?
It burns
Give a culinary application of sugar’s caramelisation property
(1/2)
Creme caramel
Caramel squares
Describe the crystallisation property of sugar
2
When a liquid has dissolved as much sugar as it can, it is saturated
If more sugar is added, crystals of sugar form in the solution and solidify when cooled
What is a liquid said to be if it has dissolved as much sugar as it can?
It is said to be saturated
When is a liquid said to be saturated?
When it has dissolved as much of a substance (sugar) as it can
What happens if more sugar is added to a saturated sugar solution?
Crystals of sugar will form in the solution and solidify when cooled
Give a culinary application of sugar’s crystallisation property
(1/2)
Confectionary
Fudge
Describe the hydrolysis property of sugar
2
Hydrolysis is the reverse of the condensation reaction which occurs during digestion
Water and enzymes split disaccharides into two monosaccharides such as lactose into glucose and galactose
What is hydrolysis?
Hydrolysis is the reverse of the condensation reaction, it occurs during digestion
Describe how hydrolysis is carried out.
Water and enzymes split disaccharides into two monosaccharides such as lactose into glucose and galactose
Give an example of hydrolysis.
The splitting of lactose into glucose and galactose through the use of water and enzymes
What two things are needed for hydrolysis?
Water
Enzymes
What is hydrolysis the opposite of?
A condensation reaction
What type of carbohydrate is split by hydrolysis?
Disaccharides
Describe the inversion property of sugar
2
Inversion occurs when a liquid sucrose solution is heated in the presence of an acid or enzyme, causing the sucrose (disaccharide) to split in to glucose and fructose (monosaccharides)
This is known as an invert sugar, and it is sweeter than sucrose
Describe how inversion occurs.
A liquid sucrose solution is heated in the presence of an acid or enzyme, causing the sucrose (disaccharide) to split in to glucose and fructose (monosaccharides)
During inversion, what must be heated in the presence of an acid or enzyme?
A liquid sucrose solution
During inversion, what must the liquid sucrose solution be heated in the presence of?
An acid or enzyme
Explain what happens to the structure of sucrose during inversion.
The sucrose is split into glucose and fructose
What is the end result of inversion?
An invert sugar is formed
Describe the Maillard reaction property of sugar.
2
The Maillard reaction is the non-enzymic browning of food due to a reaction between certain amino acids and sugars under dry heat
It produces an attractive brown colour and a crust with an appetising flavour
Give a culinary application of the Maillard reaction property of sugar
(1/3)
Shortbread biscuits
Roast potatoes
Roast meat
What is the Maillard reaction?
The non-enzymic browning of food due to a reaction between certain amino acids and sugars under dry heat
What two things are involved in the Maillard reaction?
Amino acids and sugars
What type of heat is required for the Maillard reaction to occur?
Dry heat
What are the results of the Maillard reaction?
It produces an attractive brown colour and a crust with an appetising flavour
Give a culinary use of the inversion property of sugar.
Jam making -
Inversion results in a smooth jam, as invert sugars dissolve easily, preventing sugar crystals from forming
Explain why invert sugars are used in jam making.
As invert sugars dissolve easily, preventing sugar crystals from forming
