The Cinnamon desktop environment in Linux Mint 15 by default stores a list of all the recently accessed files in the “Recent Files” section which is displayed whenever Menu is accessed.
Here is how to turn this off :
Right click on Menu and select “Menu settings”.
Then, remove the tick next to “Show recent files” and close the dialog box.
From now on, whenever Menu is accessed, there will be no list of recently accessed files.