What is acrolein?
- Small simple molecule
- Should be avoided
Structure of acrolein?
- Chain of 3 atoms
- 1 H and 1 O attached
- Low molecular weight
- Polar (moderately)
- Fat and water soluble
- 2 functional groups
- One is a double bond that is reactive
- The second is the aldehyde group which is reactive and makes it polar
Real name for acrolein?
- Prop means there is 3 carbon
- en means double bond
- al is aldehyde
Form of acrolein at room temp?
Liquid because it is relatively small and highly polar
Acrolein and vaporization?
- Vaporized at low temp
Acrolein odor and irritant?
- Has strong pungent odor and because of its chemical reactivity it is a irritant of eyes, skin and mucous membrane
Where is acrolein found?
- It is manufactured and utilized on a commercial scale for plastics production and herbicide.
- Once used a chemical weapon
- Cigarette smoke
- When oils are heated
- Most fats and oils are hydrophobic so very hydrophibic and little water present
- As the temp of oils rises any water present will vaporise and cause bubbling at 100degree and oil temp will continue to rise
- When it gets two hot it can combust or deteriorate
Heated oils and decomposition
Another observation is that oils become unstable and
decomposition will occur before any boiling of the oil
can take place. This problem becomes worse when oil
is used repeatedly, with the oil deteriorating, and also
becoming contaminated with particles of food. This
explains why it is strongly recommended that oil in
deep fryers should be changed regularly.
Smoke point of oils?
- This is the temperature at which the oil starts to emit smoke . Each type of oil has its own characteristic value
and some are quite low (around 160C) ranging up to
temperatures as high as 240C
- Smoke point can be increased with refined oils
- The more a oil is used the smoke point will decrease
Acrolein produced in cooking?
- People oil its cooked under very high temps acrolein can be formed
- Can be seen by the blue colour and pungent smell
- Possible carcinogen
- As well as being unpleasant and a likely carcinogen,
acrolein is also highly flammable as indicated by the
extremely flash point (Table 1). The flash point is the
temperature at which a material starts to be sufficiently
volatile so that there is a flammable mix with air. So we
need to take appropriate precautions to avoid
overheating when heating oils.