You might want to check out /u/caffarelli 's excellent answer in this old thread: How did the Tomato come to be such an integral part of Italian cuisine?

There's always room for discussion, but perhaps these previous topics found through the search function will answer your inquiry.

• How did the Tomato come to be such an integral part of Italian cuisine?

• Italian cooking before the introduction of the tomato

• What was Italian food like in the 14th and 15th Centuries?

• What was Roman/Early Middle Ages food like in Italy?

• What were some Old World cuisines like before the Columbian Exchange?

• When did "traditional Italian" cuisine start and what made it happen? The Roman food is almost nothing like it.

If you prefer the visual medium:

http://www.sbs.com.au/food/article/2016/07/11/episode-guide-eating-history-italy