CHEMISTRY OF COOKING

Question 1

Flavour

Answer 1

many are aldehydes
has to be volatile and turn into gas but not too much that is too fast

Question 2

alkane

Answer 2

non polar
LDF
v voltaile

too quick to lost quickly

Question 3

alcohol

Answer 3

very polar OH
H bondin g
not volatile

so doesn’t work as flavour

Question 4

small or large molecules more volatile?

Answer 4

small

Question 5

small aldehyde

Answer 5

soluble in H2O due to non polar hydrocarbon tail to c=o / -H polar ratio

cook in oil

Question 6

large aldehyde

Answer 6

large non-polar hydrocarbon tail compared to polar head (C=O/-H)

cook in water

Question 7

oxidation alcohol in relation to flavour

Answer 7

alcohols - aldehyde (pleasant flavour) - carboxylic acid (not pleasant)

Question 8

Oxidation of oils and fats in relation to flavour

Answer 8

mainly oils

unsaturated becomes saturated (break double bonns) 2 x C=O introduced

which is 2 aldehydes which are volatile

however these aldehydes are not so pleasant and are RANCID

Question 9

Slow down oxidation of food

Answer 9

cold
pack in vacuum
pack in N atmosphere
add antioxidants

Question 10

antioxidants and preventing oxidation of food

Answer 10

Antioxidant itself is oxidised

e.g. Vitamin C
C6H8O6 —> C6H6O6 + 2H+ + 2e-