Properties/uses of a named emulsion prac (1 Viewer)

[nesstar]

Perform a first-hand investigation to gather information and describe the properties of a named emulsion and relate these properties to its uses

Could someone out there who actually did perform a first hand investigation for this point plz give me a run down - thanks.

 

[mystify]

We basically made mayonnaise which is an emulsion in the lab. This was done by first combining vinegar and egg yolk (note that the lecithin in the egg yolk acts as an emulsifier) and then slowly adding oil in intervals so that it is suspended homogenously throughout the vinegar and is stabilised by the lecithin emulsifier. Hence, mayonnaise an edible substance was formed with all its components homogenously mixed to give a smooth flavour and texture 'thanks to' the lecithin emulsifier instead of all the component ingredients' flavours standing out separately.

By the way the lecithin acts by 'digging' its non-polar (i.e hydrophobic tail) into the oil droplets forming tiny micelles which are repelled from each other due to electrostatic forces WHILE the polar/hydrophilic head is attracted to the polar vinegar. Thus, a homogenous dispersion of small droplets of one liquid (vinegar) throughout the other (oil) is formed.

Hope that sort of helps

 

[nesstar]

thanks so much...I'm going to pretend i did that!!

 

[Premus]

So can we say that Mayonnaise is an oil in water emulsion?

 

[mystify]

So can we say that Mayonnaise is an oil in water emulsion?

Mayonnaise is an oil in vinegar (or you could use lemon juice) emulsion and lecithin in egg yolk acts as the emulsifier.

 

[mr EaZy]

what other kinds of emulsions are there, and do we really need to know them,??

 

[mystify]

Milk, salad dressings, paint and creams (such as skin moisturisers, sun lotions etc) are other emulsions along with the mayonnaise already mentioned. You don't need to know how they are made they're just examples of emulsions.... the one emulsion that you do need to know is the one that you do as a mandatory prac (we did mayonnaise) just so that you understand how an emulsifier helps to homogenously disperse small droplets of one liquid throughout another.