How to do a string comparison with a enum

Question

I have a enum model as below,

public enum brand {
    Maxx,
    Rems,
    All
}

I have a WebAPI method, which accepts string brand as a parameter,

public IHttpActionResult GetItemDetails(string brand)

I need to do a string comparison of my input parameter brand against the enum.

Could one please suggest what is the best way to do it.