2.3 Chemistry of Cooking Flashcards
Define “Volatile molecule”
A small molecule that can easily evaporate into a gas
Impact of Hydrogen bonding on volatility
If H-Bonds are present, flavor molecule is less volatile
Water-soluble functional groups
Hydroxyl (-OH)
Carboxyl (COOH)
Amino (NH2)
Amide (-CONH-)
Oil-soluble functional groups
Alkane (C-C)
Alkene (C=C)
Carbonyl (>C=O)
Aldehyde (-CHO)
Ester Link (-COO-)
General rules of polarity
Only C & H, non polar
With O or N, more likely to polar
Non-polar, long CH chains cancel out small polar bits.
What functional groups do Ketones and Aldehydes both have?
Carbonyl (>CO)
Difference between Aldehydes & Ketones
Aldehydes have their carbonyl group on the last carbon.
Ketones have theirs anywhere else in the chain
Smallest aldehydes and ketones?
Methanal
Propanone
Define Oxidation and Reduction in Carbon Chemistry.
Oxidation: Increase in O:H
Reduction: Decrease in O:H
Define Primary Alcohol
The Carbon attached to the OH has 1 other C attached
Define Secondary Alcohol
The Carbon attached to OH has 2 other Carbons attached
Define Tertiary Alcohol
The Carbon attached to the OH has 3 other Carbons attached
Oxidation of Primary Alcohols
Alcohol —> Aldehyde —> Carboxylic acid
Oxidation of Secondary alcohols
Alcohol —> Ketone —> No further oxidation
Oxidation of tertiary alcohols
Tertiary alcohols can’t oxidize
What can be used to oxidize primary/ secondary alcohols/ aldehydes?
- Acidified Potassium Dichromate
- Hot Copper Oxide
Colour changes?
Acidified Potassium Dichromate
Fehling’s/Benedict’s Solution
Tollen’s reagent
Orange - Green
Blue - Orange
Colourless - Silver mirror
Define Antioxidant
Molecules that reduce the rate of oxidation reactions & are often added to foodstuffs to minimize oxidative damage
Term used to describe spoiled foodstuffs
Rancid(ity)
