Extract Uppercase Words From A Cell

I am looking for a formula that would extract uppercase words from a cell. I have cells containing this kind of sentences:

"FROZEN PRODUCTS;Frozen avocado;FROZEN FISH;SweeT things;"

so I started with this Macro to extract uppercases and punctuation:

Public Function majuscules(zone)
Dim sel As Object
Dim i As Integer
Application.Volatile
For Each sel In zone

[Code] ........

It works pretty well but gives all the uppercases, and what I want is only those of words fully in upper.

Is there a way to tweak this formula so it gives all the uppers that touch another upper.

In the example case, it should return:
"FROZEN PRODUCTS; ;FROZEN FISH; "

The little cherry on the cake would be if it could give me:
"FROZEN PRODUCTS; FROZEN FISH"