Oxidation And The Chemistry Of Cooking

Question 1

What are alcohols?

Answer 1

Alcohols are carbon compounds that contain the hydroxyl functional group, -OH.

Question 2

What are the 3 different types of alcohols called which the alcohol can be divided into?

Answer 2

• Primary - Joined to the end of the carbon chain.
• Secondary - Joined to an intermediate carbon atom.
• Tertiary - Joined to an intermediate carbon atom which also has a branch attached.

Question 3

Why are alcohols soluble in water?

Answer 3

Alcohols are soluble in water as they contain the polar hydroxyl group. (-OH)

Question 4

Out of Primary, Secondary and tertiary alcohols, which alcohol does not undergo oxidation?

Answer 4

Tertiary alcohols

Question 5

What do primary alcohols produce when they are oxidised?

Answer 5

Primary alcohols produce ALDEHYDES when they get oxidised.

• Aldehydes have C=O at the end of the carbon chain and has a hydrogen attached to it.

Question 6

What do secondary alcohols produce when they are oxidised?

Answer 6

Secondary alcohols produce KETONES when they are oxidised.

• Ketones have C=O joined to two other carbon atoms and does not have a hydrogen atom attached to it.

Question 7

What is aldehydes and ketones functional group?

Answer 7

CARBONYL GROUP - it can be identified by the presence of C=O.

Question 8

What are the 3 common oxidising agents that can be used to distinguish between aldehydes and ketones?

Answer 8

Aldehydes can oxidise but ketones cannot and the 3 oxidising agents are:

• Fehling’s Solution
• Tollen’s reagent
• Acidified Potassium dichromate

Question 9

How are carboxylic acids produced?

Answer 9

Carboxylic acids are produced from the oxidation of primary alcohols and aldehydes.

Question 10

What does oxidation involve?

Answer 10

Oxidation involves an increase in O:H ratio.

Question 11

What are flavour and aroma molecules in often?

Answer 11

Aldehydes and ketones

Question 12

What can carboxylic acids react with to form salts?

Answer 12

Carboxylic acids can react with bases to form salts.

Question 13

What method is most commonly used to prevent oxidation?

Answer 13

A common method of preventing oxidation involves the addition of an antioxidant to the food.

Question 16

What is the most common antioxidant?

Answer 16

Ascorbic acid (Vitamin C)

Question 17

What will polar molecules dissolve in?

Answer 17

In water

Question 18

What will non-polar molecules dissolve in?

Answer 18

In oil