Web API Authentication Response Properties

I am developing a web service using ASP.NET Web API. I am using ASP.NET ID to generate authentication and token. I need to return an extended property in a json token response. So far, I can return an extended string property to which I am sending a json string obtained by serializing a custom class object to json. Below is the code of my provider:

public class ApplicationOAuthProvider : OAuthAuthorizationServerProvider
{
    public override async Task ValidateClientAuthentication(OAuthValidateClientAuthenticationContext context)
    {
        await Task.Run(() =>
        {
            context.Validated();
        });            
    }

    public override async Task GrantResourceOwnerCredentials(OAuthGrantResourceOwnerCredentialsContext context)
    {
        await Task.Run(() =>
        {
            var loginResponse = new AccountManager().Login(context.UserName, context.Password);

            if (loginResponse == null)
            {
                context.SetError("invalid_grant", Resources.Messages.InvalidGrant);
                return;
            }

            var identity = new ClaimsIdentity(context.Options.AuthenticationType);

            IDictionary<string, string> data = new Dictionary<string, string>
            {
                { "userData", JsonConvert.SerializeObject(loginResponse) }
            };
            AuthenticationProperties properties = new AuthenticationProperties(data);

            Microsoft.Owin.Security.AuthenticationTicket ticket = new Microsoft.Owin.Security.AuthenticationTicket(identity, properties);
            context.Validated(ticket);
        });            
    }

    public override Task TokenEndpoint(OAuthTokenEndpointContext context)
    {
        foreach (KeyValuePair<string, string> property in context.Properties.Dictionary)
        {
            context.AdditionalResponseParameters.Add(property.Key, property.Value);
        }

        return Task.FromResult<object>(null);
    }
}

      

        
        
        
      

    

Now in my answer I have a property like. "userData" : "<Json String>"

, whereas I wanted to assign json object (not json string) to userData. Is it possible?