Brian Teeling and Emma Roche says the presence of the company, which also run three Direct Provision Centres, would cause "irreparable reputational damage" to the gallery.
Aramark have been awarded the catering contract to run the café in the gallery, despite objections from four artists.
Emma Roche explains why she decided to remove her work:
"There's pressure on institutions all over the world to do better in terms of having a more diverse program in their in their art galleries. So I think to align themselves with a company that has questionable quality of the foods even back on reputation is just not really good enough."
