In packaging, a means of ensuring that food remains sterile and free from bacteria or other harmful microorganisms. (The word septic refers to infection by a pathogenic organism; aseptic means free from such pathogens, while the more familiar term antiseptic refers to a substance that kills septic pathogens.)
Aseptic packaging is the final step in aseptic food processing, in which food products are continuously sterilized, ensuring that no microorganisms—which cause either food decay and/or food poisoning—are present. Aseptic packaging ensures that the containers for the food are also sterilized continuously and that the food is inserted into the container in a completely sterile environment.
Although Louis Pasteur is often the first name that comes to mind when we think about food sterilization, the process dates back to the Napoleonic Wars and, in fact, to the Napoleonic army's difficulty in obtaining food from local merchants, as the money the French Army was using (a type of currency invented by the Revolutionary government) was pretty much worthless elsewhere in Europe. In response to a prize started by Napoleon for the promotion of industry, a champagne bottler named Nicholas Appert looked into the problem of food preservation. He found that if you put food in a champagne bottle, seal it tightly, and boil it for long enough, the food within keeps for a very long time. He patented the process, and wrote a book on the subject. Preserved food eventually came out of bottles and into tin cans when the process migrated to England (curiously, the English patent for the process of preserving foods saved from financial ruin a man named John Gamble, who had lost a great deal of money when the Fourdrinier brothers' automated papermaking machine failed commercially; see Fourdrinier), as tin was more plentiful in England than in France. Although the first versions of tin cans required the use of a hammer and chisel to open (no one had yet invented the can opener!), the process eventually caught on, especially once Louis Pasteur discovered exactly why it was that heating canned foods preserved them.
Aseptic packaging and processing can be accomplished—in modern times—in a variety of ways. The processing and packaging equipment itself is often heated to a temperature of 300:320oF for a preset amount of time. The food itself then must immediately be run through the equipment while it is sterile. The packaging itself can be sterilized by steam, heat, radiation, or hydrogen peroxide. The can was the first aseptic packaging container, but recent developments have broadened the range of containers and packages that can be filled aseptically. In the 1970s, the Irvine, California-based Scholle Corporation invented the first aseptic bag-in-box packaging, which uses flexible materials, sterilized by gamma radiation, and filled immediately after sterilization. Food products packaged in such a way include ketchup, tomato products, ice cream toppings, and sliced fruits. FDA regulations, however, restrict the bag-in-box process to acidic foods only. In the early 1980s, the use of hydrogen peroxide as a sterilizing agent was allowed by the FDA, and the aseptic packaging industry took off. Most form/fill/seal packaging machines sterilize the packaging (usually a multi-ply thermoplastic material bonded to foil, duplex paper, or other type of laminate) with hydrogen peroxide and heat. Next, the device forms the material into the appropriately-shaped package, fills it, and seals it. Form/fill/seal machines are widely used in industry now—not only for traditional can packaging, but also for plastic soft drink containers, milk cartons, and other plastic or plastic-laminate packaging. (See Form/Fill/Seal and Food Packaging.)