You can open the PDF file created with PDFsharp with e.g. Microsoft Wordpad.
In the file from my screen shot above there are no quotes in the Author field:
Code:
/CreationDate(D:20150331144251+02'00')
/Creator(QBX Online Version 14.331.1420.0 \(qbx-online.de\))
/Author(empira Software GmbH, Troisdorf)
/Keywords(Erstellt mit empira Krankenhaus-Qualitätsbericht-Manager QBX Online)
/Subject(Kontrolldokument zur Datenbankversion des Qualitätsberichts \(XML\))
/Title(Musterklinik)
/Producer(PDFsharp 1.50.3685-sl \(www.pdfsharp.com\))
So in this case Adobe Reader adds the quotes at display time.
Henning wrote:
It is possible for me to create a document with two keywords (one comma) in Adobe Acrobat without the resulting quotes.
Please post such a file so I can see how they do it.