Angular Error assing “*” to a var declared in scope

Mi problem is this, i have declared in the scope the var :

$scope.submit={
 next:"",
 formparams:"",
 value:""

};

In mi html i have :

     <div>
   <div ng-repeat="opcion in menu.opciones"><label> Opcion: </label>
     <input id="{{opcion.opcion}}" type="radio" name=grupo
      value="{{opcion.Submit}}+{{opcion.opcion}}" ng-model="submit.next"
      ng-change="submit.value={{opcion.opcion}}" ng-required="true"required> {{opcion.opcion}}                          
    </input>
</div></div>

the array of options contains something like {1,2,3,*}

When i select every numeric option is working fine, but when i select the "*" in the console of the browser appear the next error :

    angular.js:9419 TypeError: a is not a function
at OPERATORS.* (http://ift.tt/25tv8JS)
at http://ift.tt/1SiuANc
at Scope.$eval (http://ift.tt/25tv9Oa)
at http://ift.tt/1SiuANe
at http://ift.tt/25tva4o
at Array.forEach (native)
at forEach (http://ift.tt/1SiuANg)
at $setViewValue (http://ift.tt/25tva4q)
at http://ift.tt/1SiuANi
at Scope.$eval (http://ift.tt/25tv9Oa)(anonymous function) @ angular.js:9419(anonymous function) @ angular.js:6843(anonymous function) @ angular.js:16786forEach @ angular.js:303$setViewValue @ angular.js:16782(anonymous function) @ angular.js:16284Scope.$eval @ angular.js:11961Scope.$apply @ angular.js:12061(anonymous function) @ angular.js:16283(anonymous function) @ angular.js:2613forEach @ angular.js:310eventHandler @ angular.js:2612

And the var is empty.

Thanks in advanced.