There must be a config file to change somewhere. I did not run into this problem with the default install of Mint MATE, but ran into it after removing brasero and installing another cd/dvd. The new program was not made the default.
With brasero, it is possible to select other cd/dvd burning software. BUT If brasero is removed, then this option is unavailable even after another cd/dvd burning software is installed.
A successful workaround is to install another cd burning utility, (in my case, K3B), then change the default from brasero to your other one (by inserting a blank disk).
After that is done, your other application will now be the default.
If I find out the easy way to do this, I will post it. (there must be a config file to simply change somewhere)