I hope it will work
app.factory('authInterceptorService', ['$q', '$location', 'localStorageService', function ($q, $location, localStorageService) {
var authInterceptorServiceFactory = {};
var _request = function (config) {
    config.headers = config.headers || {};
    var authData = localStorageService.get('authorizationData');
    if (authData) {
        **config.headers.Authorization = 'Bearer ' + authData.token;**
    }
    return config;
}
var _responseError = function (rejection) {
    if (rejection.status === 401) {
        $location.path('/login');
    }
    return $q.reject(rejection);
}
authInterceptorServiceFactory.request = _request;
authInterceptorServiceFactory.responseError = _responseError;
return authInterceptorServiceFactory;
}]);
For more details,
http://bitoftech.net/2014/06/09/angularjs-token-authentication-using-asp-net-web-api-2-owin-asp-net-identity/