Alex
Yes, you can use external data files for that purpose among orher things.
They will allow you to save certain bits of data, such as property values, inside a file that exists outside the game, and unless specifically scripted to be deleted, will persist between game sessions.
Here are a couple of videos on the topic that should help you.
Introducion to Data Files and how they work
How to use JSON's (a type of data file you can save as) for your games and the benefits of using them