Shopping in Puerto Rico is very similar to shopping in New York with a few notable exceptions. Depending on the supermarket, there may be varying amounts of U.S. brands available. For example, Pueblo Supermarkets tend to rely heavily on U.S. brands for their inventory, so you can probably find any product you were used to using in the States there. On the other hand, Grande and Econo Supermarkets tend to get more local products and products from Spain, Colombia, and Costa Rica, and may be missing some U.S. brands. There will also be some U.S. products that you've probably never seen in your supermarket back home in the U.S., for example, tiny pullet eggs sold loose and marked with "U.S. Dairy" inked onto each egg, or large bags of no-name frozen chicken. Both of these are sub-standard, government surplus type products which are sold much more cheaply than the excellent Puerto Rican fresh products in an attempt to undercut the local market. These are to be avoided at all costs.
Superficially, the supermarkets look just like their U.S. counterparts in terms of layout and display techniques. However, the produce area will immediately impress the newcomer with the piles of gnarled root vegetables (e.g. yuca, malanga, yautía, ñame, etc.) which are staples in the Puerto Rican diet. Large green and orange squashes or pumpkins are very common, since they are often used in the preparation of stewed red, white, or black beans (habichuelas) which are present at every meal. Fresh green vegetables like broccoli, green beans, spinach, and asparagus are generally also available, but much more expensive, less popular, and often consumed in canned rather than fresh forms. Many of my students at the UPR rarely eat any of these.
The most common green vegetable is lettuce, either the iceberg variety from the U.S. or an exceptionally tender and tasty leafy variety grown on the island, generally accompanied by a sliced tomato (often pink rather than red). Corn on the cob is sometimes available, almost always imported, but most people eat their corn from a can unless they go to Church's Chicken and order a mazorca. Onions, garlic, and peppers are grown locally and absolutely essential for the preparation of the local condiment known as sofrito.
In the fruit section, tropical selections abound (papayas, mangos, pineapples, coconuts, oranges, green lemons, etc.). The large plantains (plátanos), available both green and ripe (the latter referred to as maduros or amarillos) and the tiny finger bananas (guineos niños) may be familiar to Americans from large urban centers, but odd to those from smaller towns. Strawberries, blue berries, and raspberries are available at very high cost, since they are all imported, as are the apples, pears, plums, and peaches (cheaper but often relatively tasteless since they are picked green and shipped to the island before ripening). You are much better off eating locally grown fruits which are quite reasonable in price and totally delicious!
The meat section is full of revelations. Again, this varies depending on the supermarket. Those supermarkets stocking more local products will sell rabbit and goat, in addition to the ever-present local chicken, imported beef, and pork from a variety of sources. Pork is the centerpiece of many Puerto Rican dishes, in particular, pork chops (chuletas), pigs knuckles (patas de cerdo), pork roast (pernil), suckling pig (lechón) and pork sausages of various types, including a nearly white sausage much like bratwurst called butifarra and a nearly black and heavily garliced blood sausage called morcilla. Bright orange Spanish chorizo
sausage may also be available. In addition they will often offer such delicacies as cow intestines for preparing the dish known as cuajito, cow brains for sesos, pig intestines and connective tissue for crunchy fried chittlings (chicharrones volaos), and organ meats like pig liver, kidneys, and heart for gandinga. These dishes tend to be more popular in the rural areas and among older people. Most of my students turn their noses up at them.