Natures Chemistry - Oxidation of Food Flashcards
What happens when hot copper (II) oxide reacts?
It goes from black to brown.
What happens when acidified potassium dichromate reacts?
It goes from orange to green.
What happens when Fehling’s solution reacts?
It goes from blue to brick red.
What happens when Tollens reagent reacts?
It goes from colourless to silver mirror.
What do hot copper (II) oxide and acidified potassium dichromate oxidise?
- Primary alcohols to aldehydes and then to carboxylic acids.
- Secondary alcohols to ketones.
What functional group do aldehydes and ketones contain?
Carbonyl (C=O).
What oxidising agents can be used to differentiate between an aldehyde and a ketone?
Fehling’s solution, acidified potassium dichromate and Tollens reagent.
How does oxidation change the Oxygen to Hydrogen ratio?
It increases it.
How does reduction change the oxygen to hydrogen ratio?
It decreases it.
Are flavour molecules aldehydes or ketones?
Aldehydes.
What happens when edible oils oxidise?
The food gets a rancid flavour.
What is an antioxidant?
Molecules that prevent unwanted oxidation reactions from occurring.
How does an antioxidant protect food?
By oxidising in replacement of the substance.
