Every day, American consumers rely on the cans, bottles, boxes and plastic that food is sold in to keep them safe. In fact, scientists research how food packaging can help preserve food and extend shelf life. Lorraine Rapp and Linda Lowen, hosts of WRVO's health and wellness show “Take Care,” recently spoke with Dr. Joseph Hotchkiss, director of the school of packaging at Michigan State University about the science of food packaging.
Linda Lowen: Every package protects its contents, but what is it providing protection against?
Dr. Joseph Hotchkiss: Actually there are a whole bunch of mechanisms by which food deteriorates, and packaging really has to be effective against all of these. Everything from oxygen, for example, which can deteriorate a lot of food, to changes in moisture content, microorganisms, including mold and things that would deteriorate food, and loss of color. There’s a whole range of things that you really have to look at each individual food and then develop a packaging system which really attacks that individual vector.
Linda Lowen: What about the idea of foods interacting with their packaging? I know the package is considered a barrier, and then there’s talk of product compatibility. How does all of that work out?
Dr. Hotchkiss: Absolutely. There are product compatibility issues. Products interact with all kinds of packaging in a variety of ways. And so, you have to consider that. Probably the most inert of all packaging is glass, but of course, you can’t package everything in glass. Canned products can interact with the can, as a matter of fact if the can is not protected from the food, the food can literally eat a hole in the side of the can. There are cases where parts of the package transferred to the food, and so there are lots and lots of food packaging interactions, many of which have implications for product safety, product quality, shelf life and so forth. We teach a whole course on this topic, as a matter of fact.
Lorraine Rapp: Speaking of shelf life, how is that determined?
Dr. Hotchkiss: Shelf life is a strange thing, because people look at a date on a product and think that that date somehow actually means that the day before that date it’s okay to eat, and after that it’s not okay to eat. However in most cases that date is actually put on there by the manufacturer simply on a quality basis. In other words, the manufacturer makes the decision, “you know what, we don’t think people should consume our products simply for quality reasons after this date.” Now there are some implications for safety, for example they put expiration dates on milk and beyond that date there is certainly a chance for lower quality. And I suppose you could argue for some kind of safety issues, it’s kind of a guideline, but they are not really set there for safety. Food products that are offered for sale have to be safe, regardless of what the date on them is or is not on there.
Linda Lowen: What about the new approach to packaging? What is active packaging?
Dr. Hotchkiss: Active packaging looks at a product and says, “you know what, the package should somehow directly help the product.” Let me give you an example—precut salad. What has allowed that to happen is in part the packaging system, which actually in many cases contains tiny, tiny microscopic holes in it that allow that lettuce to breathe at a certain rate to produce the maximum shelf life and quality of that precut lettuce product. So that is active, it is actively helping the lettuce last longer.
You can hear more of this interview WRVO's health and wellness show Take Care, Sunday at 6:30 p.m. Support for this story comes from the Health Foundation for Western and Central New York.