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KS3 Enzymic Browning

Total questions: 15

Worksheet time: 14mins

Name
Class
Date
1.

Enzymic browning occurs when...

a)

enzymes are damaged and oxidation takes place

b)

Fruit is spoiled and unsafe to eat

c)

Fruit goes mouldy

d)

Food gets bacteria on it and makes your enzymes go brown

2.

Organize these foods into the right categories

Categorize the following

Tomatoes

Cucumber

Apple

Pear

Watermelon

Carrots

Swede

Mushrooms

Celery

Peas

Fruit
Vegetables
3.

This antioxidant is often used in fruit salads in the form of orange juice to prevent enzymic browning.

a)

Vitamin C

b)

Protein

c)

Fat

d)

Calcium

4.

Match the following sentences...

a)

Enzymic browning can be prevented by

1.

acid, heat or water.

b)

The enzyme in fruit that causes fruit to go brown is called

2.

polyphenol oxidase

c)

Polyphenol oxidase is an

3.

enzyme.

d)

Enzymes are

4.

catalysts that speed up reactions.

e)

Pigmentation occurs when fruit browns because

5.

the oxygen reacts with the enzymes.

5.

Enzymic browning is a ...

a)

Biological reaction

b)

Emotional reaction

c)

Chemical Reaction

d)

Allergic reaction

6.

Match the following

a)

The enzyme in fruit which causes it to go brown is...

1.

Polyphenol Oxidase

b)

Enzymic browning is...

2.

a chemical reaction that causes fruit do go brown when exposed to oxygen

c)

Enzymes are catalysts...

3.

they speed up chemical reactions

d)

Apples, potatoes, avocados, bananas and aubergines are fruits and vegetables...

4.

that are commonly affected by enzymic browning

e)

When the cell of a fruit is cut open,

5.

enzymes react with oxygen in the air and oxidation takes place.

7.

To prevent enzymic browning you can use an acid such as...

a)

Water

b)

Apple juice

c)

Lemon juice

d)

Bicarbonate of soda

8.

Fruits and vegetables that are affected by enzymic browning shouldn't be stored in...

a)

Metal containers

b)

Plastic containers

c)

Glass bowls

d)

Paper plates

9.

Polyphenol oxidase is an (a)   this acts as a catalyst and speeds up reactions.

10.

This type of cooking method can prevent enzymic browning...

a)

Boiling

b)

Roasting

c)

Blanching

d)

Grilling

11.

The following methods can be used to preserve fruits and vegetables and stop enzymic browning from happening...

a)

Keep in an airtight container to remove oxygen

b)

Cover with cold water to prevent oxygen mixing with the damaged enzymes

c)

Add an acid which denatures the protein and stops browning taking place

d)

All of the above

12.

The ​ (a)   process which occurs in ​ (b)   by the enzyme ​ (c)   , which results in brown pigmentation is called ​ (d)  

Choose from the below words
chemical
fruits and vegetables
polyphenol oxidase
enzymic browning
biological
meat and fish
oxygen
13.

When referring to fruits and vegetables, ripening means...

a)

a fruit changing colour when combined with oxygen

b)

a fruit or vegetable maturing so that it is ready to eat

c)

a fruit that has been picked from a tree

d)

a fruit or vegetable that is unsafe to eat

14.

To prepare fruits you should always use a...

a)

Blue chopping board

b)

Brown chopping board

c)

Green chopping board

15.

The chemical reaction when proteins are chemically altered either by acid, agitation or heat is known as...

a)

Coagulation

b)

Caramelisation

c)

Dextrinisation

d)

Denaturation