Use keyboard for accessing Emacs Menu
I found a good workaround in emacs (beta) forum:

https://emacs.stackexchange.com/questions/3911/access-menu-bar-using-keyboard-on-mac-os-x

(define-key global-map (kbd "C-&lt;f2&gt;")
  (lambda ()
    (interactive)
    (x-popup-menu (list '(0 0) (selected-frame))
                  (mouse-menu-bar-map))))