Funding for this research was provided by:
Bundesministerium für Bildung und Forschung (Extraktionsverfahren bioaktiver Naturstoffe aus Hopfen)
Received: 5 November 2018
Accepted: 30 June 2019
First Online: 10 July 2019
Ethics approval and consent to participate
: Approved by the Ethics Commission of the Faculty of Medicine, Technical University of Munich on January 08, 2018. Participants gave their informed written consent before beginning the questionnaire.
: Not applicable.
: The authors declare that they have no competing interests.