Mammalucco is Italian for MAMLUKS, an ethnic group of non-muslim origin who established a Sultanate in Egipt circa 1250. Their brief history: here

Mammalucca, as a feminine gender, applies to any name of feminine gender in Italian, for example "epoca mammalucca" = age of the mamluks, "alla mammalucca" = in the style of mamluks.

I don't see any derogating meaning in the word, but it really sounds awful.

Un abrazo,
Andrés