Angularjs ng-options: Use object property as value instead of array index

In the code below, AngularJS ng-options renders the value but records the position in the array and not the value.

I get the following json:

[{"iduniforme":1,
  "nomeuniforme":"Uniforme 5 itens",
  "itensuniforme":[{...},{...},{...},{...},{...}]},
 {"iduniforme":2,
  "nomeuniforme":"Uniforme 7 itens",
  "itensuniforme":{...},{...},{...},{...},{...},{...},{...}]}]

Using Angularjs ng-options, I mount my select:

<div class="form-group">
   <label>Uniforme da Equipe</label>
   <select class="form-control" name="uniforme" id="uniforme"
   ng-model="uniforme" ng-options="x.nomeuniforme for x in listaUniformes">
   <option value="">Selecione o uniforme</option>
   </select>
</div>

I can render normally, ie the options appear correctly, however, ah but when I submit the form the amount recorded is the position within the array [0] or [1] and not the value in "nomeuniforme" in this case would be "Uniform 5 items" or "Uniform 7 items".

How do I resolve this? I need to register the value "Uniform 5 items" or "Uniform 7 items" in the base.