Americans gulped down almost 700 million gallons of orange juice in 1989, most of it frozen concentrate sold either in freezer sections or reconstituted and sold refrigerated.

Figuring out the differences in all the forms of orange juice sold can be confusing. Here are the various types and their characteristics, according to the Florida Citrus Commission:

Frozen concentrate -- This is made from freshly squeezed juice that is concentrated using an evaporation process and then frozen. Consumers add water. Frozen concentrate, which usually comes in six- or 12-ounce cans, is found in the supermarket freezer section and accounts for almost 42 percent of orange juice sales.

Reconstituted frozen concentrate -- This is made from frozen concentrate, but the manufacturer rather than the consumer adds the water. It is also pasteurized, which inhibits the growth of fungus and helps to extend the shelf life. The front label must state that the juice is made from concentrate. It is typically packaged in paperboard, plastic or glass containers in the quart, half-gallon or gallon size, and is sold in the dairy section. This type of OJ also accounts for approximately 42 percent of the market.

Pasteurized -- These products are made from freshly squeezed juice, which is then pasteurized with flash heating. It is sold in paperboard, glass or plastic containers, usually in the dairy section of the store in sizes ranging from one quart to one gallon. It is ready-to-serve juice and the label must state that it is pasteurized or not from concentrate. This category constitutes about 14 percent of sales.

Canned -- This form of juice is found in a can or bottle on the dry goods shelf. It is a pasteurized juice that has an extended shelf life of more than a year as a result of the canning process. Nowadays, only 1.3 percent of total orange juice sales is from canned juice.

Fresh-squeezed -- In Washington-area stores, this kind of juice is typically found in produce sections, right next to the juicer. It is sold in some dairy cases. Usually packaged in paperboard, glass or plastic containers, fresh-squeezed juice should be clearly labeled as such. It accounts for less than 1 percent of the orange juice market.

Fresh frozen juice -- This juice is freshly squeezed, packaged and flash frozen without any further processing. It is usually sold in eight-ounce and one-quart plastic containers and is found in the frozen-food section of supermarkets. This accounts for a minuscule portion of orange juice sales.

Aseptically packaged -- This type of juice is usually found with other canned or bottled juices on the dry goods shelf. Aseptic containers are made of paperboard and are sterilized before the juice is packaged. The juice itself is pasteurized and the product is usually shelf-stable for six months to a year or until opened. This too accounts for a minuscule portion of OJ sales.