An innovation like antimicrobial packaging, brought about through chemical-engineering expertise, helps improve the safety and convenience of our foods. Courtesy Ted Labuza, PhD.
By developing novel packaging methods chemical engineers have helped expand the bountiful selection of fresher-tasting, longer-lasting foods we enjoy today. These modern packaging marvels run from basic to high tech and include
- Traditional metal cans,
- Multilayer packages that allow heat sterilization right in the container, and
- Packaging that controls oxygen and carbon dioxide levels to slow ripening and to reduce spoilage.
The protection provided by specialized packaging makes it possible for foods to be shipped over greater distances and stored on the shelf for longer periods. Protecting perishable foods—fruits, seafood, and meat—against spoilage and decay has helped connect distant food sources with new markets worldwide. We now expect to see strawberries, mangoes, and kiwi fruit in our markets year round. Among the more popular packaging methods being used are sterilization, vacuum packaging, and multilayered packaging.
Sterilization
To retard spoilage people have experimented with dehydration, smoking, salting, pickling, candying, and even the use of certain spices. It is now common knowledge that oxidation, bacteria, molds, and microorganisms cause foods to spoil and that sterilization can help prevent them.
Chemical engineers have helped devise many advanced sterilization techniques to preserve foods and protect consumers from food-borne illnesses. These procedures include
- High-temperature pasteurization and canning,
- Refrigeration and freezing, and
- Irradiation.
Vacuum packaging
Chemical engineers have been intimately involved in developing vacuum packaging. The food is placed into a gas-impermeable bag, the air is vacuumed out, and the bag is sealed. This process reduces the oxygen content inside the bag so that microbes cannot survive.
Later improvements on traditional vacuum packaging include controlled-atmosphere packaging (CAP) and modified atmosphere packaging (MAP), both of which represent monumental chemical-engineering breakthroughs in the field of food processing.
During CAP oxygen and carbon dioxide levels inside the food-packaging environment are controlled to limit fruit and vegetable respiration. This technique slows ripening and spoilage of fresh produce and prolongs the shelf life.
MAP is a more advanced version of CAP that not only slows ripening but also prevents many natural reactions that cause foods to become rancid and spoil.
Brick packs and retort pouches
The invention of chemically sterilized brick packs is another important chemical-engineering contribution to food safety and convenience. These multilayer packages are widely used to package juice, milk, tomato sauce, and countless other products to protect the contents from spoilage without the need for refrigeration. The ingenious brick-shaped package is typically constructed from high-quality paperboard, plastic, and aluminum.
More recently, flexible, laminated retort pouches have been widely used for food preservation. Multilayered retort pouches are filled with wet foods, sealed, and then heat treated to sterilize the contents. The food within the pouch is never exposed to air again until eaten, so it can be stored without refrigeration.
Copyright © 2009 American Institute of Chemical Engineers and Chemical Heritage Foundation. All rights reserved.