And packaging is part of the safeguard for America's prepared foods

With bioterrorism a real possibility, food industry authorities are quietly discussing what steps can be taken to increase the security of packaged foods. So daunting is the challenge, however, that one expert facetiously suggests "shrink-wrapping delivery trucks" as a distribution safeguard.

The shrink-wrap suggestion was prompted by an October incident in which the message, "Anthrax contamination," was spray-painted on a boxcar loaded with flour. The message was a hoax, but it added fuel to the food-security debate. Pre-harvest and in-plant contamination dominate the discussion. As the final link in the security chain, packaging also must be considered.

"Probably 30 to 40 percent of products in the supermarket have some type of tamper-evident feature," guesses Larry Rebedos, marketing manager at Lake Forest, Ill.-based Pactiv. In Europe and Asia, tamper-evident packaging is more prevalent, he points out. While a certain level of security is a given in some categories, it is nonexistent in others. The bread aisle is an example, Rebedos notes: a twist-tie is all that stands between passersby and the contents of those polybags.

Bakery and dairy products make particularly inviting targets for bioterrorists, warns Ted Labuza, professor of food science and engineering at the University of Minnesota, because the packaged product is unlikely to undergo further processing and because children are primary consumers.

The vast majority of rigid packaging includes tamper-evident features, though the level of assurance varies tremendously. Drop-lock closures are used extensively with fluid milk products, and those systems tend to be less reliable indicators. Poor design can be a problem: The lip of the bottle's neck may not be sufficiently pronounced to cause the plastic ring to break. Process parameters also may be to blame: Engineer Howard Leary of Luciano Packaging Technologies, Somerville, N.J., suggests food manufacturers "validate their packaging systems and apply process controls" to ensure that rings break and seals perform as expected.

Foil liners under the cap add a higher level of security, and Billy Epperson of Portola Allied Tool, Michigan Center, Mich., a few dairy processors are asking about those systems. After the cap is applied, the bottle passes under an induction sealer unit, which uses high frequency to heat the foil and seal it to the bottle's mouth.

Absent public hysteria, rapid change is unlikely. "To some degree, food packaging secruity is a marketing issue today," notes Leary. Still, it's the last link in the farm-to-table chain and a topic for renewed scrutiny.