Food Engineering

Food Packaging: Wrappers help kill microbes

August 13, 2003
Packaging systems are being designed to meet the food safety imperative.



Spray systems that apply ingredients are being adapted to deliver antimicrobials on trayed meat products. Source: AutoJet Technologies



Shouting “Recall!” in a ready-to-eat meat plant is akin to yelling “Fire!” in a crowded theater: fear and panic is sure to follow. No segment of the food industry is more concerned about the potentially lethal effects of good product gone bad than these processsors.

As with dairy, the greatest potential for contamination is in the post processing, pre-packaging stage. While dairies have addressed that danger with sanitary filling systems, ready-to-eat meats still are experimenting with risk-lowering solutions.

One possibility that is generating potential for contamination is the RP-SSP flash pasteurization unit, a joint project of Alkar Corp. and RapidPak, two Lodi, Wis., firms under the umbrella of the Management and Facilitator Capital Fund. The group also includes Madison, Wis.-based Sani-Matic, specialists in CIP and other sanitation technology.

RapidPak makes 3-A certified horizontal thermoform/fill/seal packaging equipment used extensively by Oscar Mayer and other high-volume processors of hot dogs, lunchmeats and other ready-to-eat products. Alkar makes ovens, chillers and cook/chill units. For the last two years, Alkar has lent its pasteurization expertise to the development of a packaging machine that flash pasteurizes hot dogs milliseconds before the film is sealed. Alkar-RapidPak plans to exhibit the unit at Worldwide Food Expo this fall in Chicago.

“The key is delivering short bursts of pressurized steam without losing any line sped and in a very controlled situation,” explains David Wildes, Alkar’s marketing director. The unit, which can be retrofitted to RapidPak equipment, adds four to six feet to packing machines that already are 30 to 40 feet long, bu the post-packaging pasteurization tanks that many processors currently employ are eliminated, resulting in a net floor space savings.

USDA and an independent lab are still gathering bacterial kill data, but preliminary results are encouraging. A 4-Log bacterial reduction on an inoculated product was achieved in one test, Wildes reports. Temperature of the steam exceeds 212¿ F.

While the firms resolve final design issues on RP-SSP, processors are attacking the microbial issue with systems of their own design. One popular approach is a prepackaging antimicrobial spray. Great precision is required to deliver thorough coverage of the antimicrobial agent without coating the package tray. Rather than engineer such a system themselves, processors are beginning to turn to specialists such as AutoJet Technologies.

“We’ve made the components of these systems for over 30 years, and about two years ago companies started calling us and saying, ‘I want the whole kit and caboodle’ of a turnkey antimicrobial spray system,” says William Kohely, vice president with Wheaton, Ill.-based AutoJet. “You can piece together a system, but it isn’t going to work as well as one that has been engineered at once, working back from the spray nozzle.”

The application temperature of the antimicrobial agent, variability between batches, whether it is ascorbic acid or some other compound and other factors influence selection of the spray tip. High-speed electric guns and extremely low flow rates also factor into the design of spray systems that use proximity sensors and sophisticated algorithms to accurately spray within a tenth of an inch of edges of trays being conveyed at rates of up to 1,000 units a minute.

For more information:

William Kohley, AutoJet Technologies

630-665-5000 ext. 1218, bill.kohley@spray.com