We traditionally make meringues by adding sugar to egg whites and foaming it up.
Incorporating air into the egg white, creates molecules that can be elongated and elasticated. The protein strands stretch around air bubbles, creating the foaming effect. This state isn’t on its own, however, very stable. If you stop whisking, the meringue starts to drop. If you over-whisk, the molecule strands will break causing the meringue to crack, like over-stretching an elastic band.
So when you take protein strands and stretch them around air bubbles, you have to stabilise them. Adding sugar does just that by creating a sticky elastic around the air bubbles and holding them.
But what if you don’t want a sweet meringue?
The simple answer is to use Xanthan Gum instead of the sugar. This stabilises without sweetening.
Xanthan Gum is a highly versatile product, often used to control viscosity as well as provide stability. It gels in the presence of Locust Bean Gum, Agar Agar or Kappa Carrageenan. It can also be used as a suspensions thickener, an emulsifier, a foaming agent, to replace gluten in yeast breads and to retard ice crystal growth in freeze-thaw situations.