Casella and Vavilov (http://en.wikipedia.org/wiki/Nikolai_Vavilov) and Von Jean-Paul Descœudres, Penelope Mary Allison, Derek Harrison identified it as an pineapple. Cassela and Vavilov were professional biologists, so they definitely knew the difference between pine and pineapple. Vavilov also best known for having identified the centres of origin of cultivated plants.

What is more interesting, pineapple came from Brazil. The article calls "Romans in Brazil", coz several Roman artefacts were found there.

1) Romans had ships, that could make transatlantic journeys. Tur Heyerdal proved that it is possible even for ancient papirus boat, without having supplies from the civilization during the journey.

2) There are favorable winds and currents linking Canare islands and Mexican bay.

3) The faraway expeditions were pretty common among Mediterenian dwelers.

4) There is pretty much Roman and Phoenician stuff found in Americas.