KS3 Enzymic Browning

1.

Multiple Choice

30 sec

5 pts

Enzymic browning occurs when...

enzymes are damaged and oxidation takes place

Fruit is spoiled and unsafe to eat

Fruit goes mouldy

Food gets bacteria on it and makes your enzymes go brown

2.

Classification

3 mins

1 pt

Organize these foods into the right categories

Groups:

(a) Fruit

,

(b) Vegetables

Peas

Celery

Tomatoes

Carrots

Watermelon

Mushrooms

Apple

Pear

Cucumber

Swede

3.

Multiple Choice

30 sec

1 pt

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

Vitamin C

Protein

Fat

Calcium

4.

Match

1 min

1 pt

Match the following sentences...

catalysts that speed up reactions.

Enzymes are

acid, heat or water.

Enzymic browning can be prevented by

polyphenol oxidase

Pigmentation occurs when fruit browns because

enzyme.

Polyphenol oxidase is an

the oxygen reacts with the enzymes.

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

5.

Multiple Choice

30 sec

5 pts

Enzymic browning is a ...

Biological reaction

Emotional reaction

Chemical Reaction

Allergic reaction

6.

Match

1 min

5 pts

Match the following

they speed up chemical reactions

Enzymic browning is...

that are commonly affected by enzymic browning

Enzymes are catalysts...

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

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

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

When the cell of a fruit is cut open,

Polyphenol Oxidase

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

7.

Multiple Choice

30 sec

5 pts

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

Water

Apple juice

Lemon juice

Bicarbonate of soda

8.

Multiple Choice

30 sec

5 pts

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

Metal containers

Plastic containers

Glass bowls

Paper plates

9.

Fill in the Blank

1 min

1 pt

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

10.

Multiple Choice

30 sec

5 pts

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

Boiling

Roasting

Blanching

Grilling

Answer explanation

By plunging fruit and vegetables into boiling hot water for a short amount of time it denatures the protein. Then plunging them into ice cold water after draining from the hot water you can stop the cooking process and retain the vegetables colour, crunch and flavour.

11.

Multiple Choice

30 sec

5 pts

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

Keep in an airtight container to remove oxygen

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

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

All of the above

12.

Drag and Drop

1 min

1 pt

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

chemical

fruits and vegetables

polyphenol oxidase

enzymic browning

biological

meat and fish

oxygen

13.

Multiple Choice

30 sec

5 pts

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

a fruit changing colour when combined with oxygen

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

a fruit that has been picked from a tree

a fruit or vegetable that is unsafe to eat

14.

Multiple Choice

30 sec

5 pts

To prepare fruits you should always use a...

Blue chopping board

Brown chopping board

Green chopping board

15.

Multiple Choice

30 sec

5 pts

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

Coagulation

Caramelisation

Dextrinisation

Denaturation

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