Egg whites can be whipped into meringue. Cream can be whipped into whipped cream. And gelatine can be whipped into marshmallows.
The key to making a foam is to beat a protein. As it is beaten, the proteins are denatured (changed from their natural state) exposing the hydrophobic (water hating) and hydrophilic (water loving) ends of the protein.
Beating the mixture also adds air. The denatured protein strands form circles around the air with the hydrophobic ends pointing in, and the hydrophilic ends pointing out towards the water. This makes lots of bubbles that we recognize as foam.
To observe the process, we made marshmallows. First we softened gelatine in some water. Then we slowly added in a simple sugar syrup and whipped it in the mixer for 15 minutes. After that, we added some vanilla, and spread it out in a pan. The pan had to sit overnight to dry out (torture not to be able to try them right away!)
The next day we cut them into squares and dusted them in icing sugar. Then we ate them ALL.
Just kidding. That would make us very sick. They are basically sugar, sugar, more sugar, and coated in sugar. Did I say sugar?
