The MiniFreak has a Snapshot feature that lets you recall previous states of your patches.
Every time you load a new patch, the previous state gets saved as a "snapshot", for the purpose of recovering lost edits. Up to 4 snapshots are stored.
Go to the "Sound Edit/Preset/View Snapshots" menu, or use the shortcut "Sound Edit" + "Save". There you'll see a list of time stamped snapshots. Click the encoder to load one.
You can read about this in the manual "4.5. Sound Edit operations".