How to convert a dynamically added SOAP webservice XML result to it's original datatype?

I have an asmx webservice(FoodWs.asmx) with a webmethod (RetrieveData) and its output data type is datatable.

 [WebMethod]
    public DataTable RetrieveData()
    {
        DataTable dt = new DataTable();
        dt.Columns.Add("Name", typeof(string));
        dt.Columns.Add("Prrice", typeof(int));
        DataRow dr = dt.NewRow();
        dr["Name"] = "Rice";
        dr["Price"] = 1000;
        dt.TableName = "Food";
        dt.Rows.Add(dr);
        return dt;
    }

I'm calling this webservice dynamically with following code instead of adding web reference in another project.

 public static HttpWebRequest CreateWebRequest()
    {
        HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(@"http://localhost:55500/FoodWs.asmx?op=RetrieveData");
        webRequest.Headers.Add(@"SOAP:Action");
        webRequest.ContentType = "text/xml;charset=\"utf-8\"";
        webRequest.Accept = "text/xml";
        webRequest.Method = "POST";
        return webRequest;
    }
public static void Execute()
    {
        HttpWebRequest request = CreateWebRequest();
        XmlDocument soapEnvelopeXml = new XmlDocument();
        soapEnvelopeXml.LoadXml(@"<?xml version=""1.0"" encoding=""utf-8""?>
                <soap:Envelope xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance"" xmlns:xsd=""http://www.w3.org/2001/XMLSchema"" xmlns:soap=""http://schemas.xmlsoap.org/soap/envelope/"">
                  <soap:Body>
                    <RetrieveData xmlns=""http://tempuri.org/"" />
                  </soap:Body>
                </soap:Envelope>");

        using (Stream stream = request.GetRequestStream())
        {
            soapEnvelopeXml.Save(stream);
        }

        using (WebResponse response = request.GetResponse())
        {
            using (StreamReader rd = new StreamReader(response.GetResponseStream()))
            {
                **string soapResult = rd.ReadToEnd();**
               HttpContext.Current.Response.Write(soapResult);
            }
        }
    }

In the Execute method the result in soapResult variable is xml string of soap result. but in the webmethod of FoodWs.asmx the RetrieveData output datatype is datatable. How can I convert the result to datatable? How can I convert the XML SOAP result to its original datatype instead of XML string?