You are right, the text of the dropdown menus will align right and need to be assigned a text-align: left, I should have noted that. You can apply the text-align on .top-bar-section ul.
The left classes should be removed, otherwise you must apply a float: none !important, which should be avoided most of the time.
The .top-bar-section ul selector is in foundation.min.css and you should overwrite it in a different style sheet that should be loaded after the foundation file — you do have a different stylesheet, don’t you? 
The .top-bar-section ul ul selector should be added to the same file.