There are some requirements for a foreign citizen who does not permanently reside in Brazil to own real property in Brazil.  Namely you must have a brazilian tax id or CPF number.  You must also present a notarized copy of your passport to the local registrar. If you are not fluent in portuguese you will have to have a translator recorded in the transaction.  This translator must be someone other than the other party in the transaction or their representative. 

For rural property such as farms, the requirements are different and other  limitations apply.

Brazilian real estate transactions are recorded at a Cartorio.  A cartorio, or registrar is a privately owned but regulated business.  They are responsible for ensuring the validity of the transaction through proper research and documentation. 

If you are not physically present for the transaction you can issue a Procuracao (Power of Attorney) to someone to represent you in the transaction.   You must do this while in Brazil as it is very difficult to do this from abroad.