Spanish / European Influence
Wheat, garbanzos, capers, olives, olive oil, black pepper, onions, garlic, cilantrillo (or cilantro), oregano, basil, sugarcane, citrus fruit, eggplant, ham, lard, chicken, beef, pork, and cheese all came to Puerto Rico from Spain. The tradition of cooking complex stews and rice dishes in pots such as rice and beans are also thought to be originally European.
African Influence
Coconuts, coffee(these two were broght by the Arabs and Corsos), okra, yams, sesamie seeds, sweet bananas, plantains, other root vegetables and Guinea hen all came to Puerto Rico from Africa. African American Slaves intoduced fried food to Puerto Rico.
United States Influence
The United States became an influence on the food once Puerto Rico became a US territory as result of the Treaty of Paris in 1898. We really influenced the way that they fried food. The early US brought olive oil for cooking and frying, but importing it from Spain made it very expensive, and cooks on the Island shifted over to lard which could be produced locally. For 50–60 years, corn oil produced in the United States took the place of lard. Galletas de soda(Cracker in tins) are an American product of the 19th and early 20th centuries that reproduce the crunchy texture of the earlier casabe bread and can be kept crunchy (in the tins) in high tropical humidity. American bacon became a big part of the cuisine. Bacon in Puerto Rico has found its way into traditional foods such as arozz con gandulas and potato salad.
South America Influence
Other foods were brought to the island from the Spanish Trade. Such as coca, avocado, tomatoes, chayote, papaya, bell peppers, and vanilla from Mexico. Potatoes and passion friuts were also brought over by the Spanish. Portuguese, Peru, and Brazil.