At dinner this evening Leila and I got into a conversation about Italian words losing the last vowel (mozzarell instead of mozzarella). If you’re not from the New York area this will sound crazy, but it’s pretty common here (I remember hearing it growing up in Connecticut as well).
When I got home I tried to track down an article I remember reading years ago about this phenomena and while I can’t remember whether this was it, a New York Times article from 2004 offers up some ideas on how this happened:
In fact, in some parts of Italy, the dropping of final vowels is common. Restaurantgoers and food shoppers in the United States ended up imitating southern and northern dialects, where speakers often do not speak their endings, Professor Albertini said.
Liliana Dussi, a retired New York district director for the Berlitz language schools, said many first- and second-generation Italians whose ancestors immigrated to the United States before World War I were informally taught Italian expressions and the names of food, some of which has ended up part of everyday language in New York, New Jersey and Connecticut.
If you want more, this Chowhound thread is pretty excellent.