Oxidation of Food

Question 1

what molecules are likely to be volatile

Answer 1

GFM lower than 300

Question 2

trend in volatility with gfm

Answer 2

lower gfm - more volatile

Question 3

if molecule contains c and h atoms

Answer 3

likely to be nonpolar - fat/oil soluble

Question 4

if molecule contains o and n atoms

Answer 4

likely to be polar - water soluble

Question 5

what is the polarity of a long hydrocarbon chain with a single polar group

Answer 5

nonpolar

Question 6

Aldehyde/ketone functional group and name

Answer 6

C=O
Carbonyl

Question 7

Where is carbonyl aldehyde

Answer 7

beginning of C chain

Question 8

Where is carbonyl ketone

Answer 8

never on the end of C chain

Question 9

Names for aldehydes

Answer 9

end in al - methanal

Question 10

Names for ketones

Answer 10

end in one - pentan-2-one

Question 11

Formula for ketones and aldehydes

Answer 11

CnH2nO

Question 12

How do you know if carbon compounds are oxidised

Answer 12

Oxygen atoms increase
Hydrogen atoms decrease

Question 13

2 mild oxidising agents

Answer 13

-Hot copper (II) oxide
-acidified potassium dichromate

Question 14

Stages of primary alcohol oxidation

Answer 14

1. aldehydes
2. carboxylic acids

Question 15

Stages of secondary alcohol oxidation

Answer 15

1. Ketones

Question 16

Using mild oxidation agents, what alcohols cant be oxidised

Answer 16

Tertiary

Question 17

Oxidation process - O:H ratio

Answer 17

O increases
H decreases

Question 18

Can ketones be oxidised

Answer 18

No

Question 19

3 oxidising agents to oxidise aldehydes

Answer 19

acidified potassium dichromate
benedicts solution
tollens reagent

Question 20

colour change acidified potassium dichromate

Answer 20

orange - green

Question 21

colour change benedicts solution

Answer 21

blue - cloudy red

Question 22

colour change tollens reagent

Answer 22

silver mirror

Question 23

what causes oxidation of food

Answer 23

oxygen

Question 24

3 compounds for flavour molecules

Answer 24

alcohols, esters and aldehydes

Question 25

Define antioxidants

Answer 25

Will prevent oxidation as they are reducing agents

Question 26

4 examples of antioxidant

Answer 26

absorbic acid (vitamin C) melatonin tocopherol carotene

Question 27

Define free radicals

Answer 27

Reactive atoms or molecules with an unpaired electron

Question 28

What does too many free radicals mean

Answer 28

attacks cell membranes which causes cell and tissue damage

Question 29

what do antioxidants do (free radicals)

Answer 29

mop them up

Question 30

what 3 compounds only form h bonds with water and not themselves

Answer 30

carbonyl aldehyde ester