If you are storing more than Portuguese in one column then you may need Nvarchar definition of your text columns data type and then using Portuguese collation on either table level or column level. You could also add it in your T-SQL code. Here is the System.Text.Encoding page and the SQL Server Windows collation page.

http://msdn.microsoft.com/en-us/library/system.text.encoding.aspx

http://msdn.microsoft.com/en-us/library/ms143508.aspx