Passenger rights in the event of a delay or the flight being cancelled are governed by the general European Parliament and European Council regulations, in particular the Directive (EC) No. 261/2004, which sets out common rules for the system of compensation and passenger assistance. It is always the company, which the passenger enters into a contract, which is responsible for providing compensation and never the Airport.
Regulations establish the airlines’ obligations rather generally, for instance the obligation to provide refreshment free of charge in the case of a delay of more than two hours for flights under 1500 km. However, it also depends on the facilities available at the given airport, whether the passengers will be given vouchers not limited to one particular catering facility, or whether the passengers are offered a meal in a particular restaurant without the option of a choice. Both cases are in line with the EU regulation.
The provider and the supplier of compensation to passengers experiencing delay is generally the handling company, which represents the given airline at the airport.