Novel Approaches to Pathogen Control

A series of recent incidents involving pathogens in peanut butter, ground beef, and chicken products has forced the food industry to recognize the continuing need for technological means of ensuring the biological integrity of food supplies.

That need is fueling the efforts of industry experts to embrace and advocate novel approaches to pathogen control.

“Our objective is to find the practical implementations that can be used immediately,” says Kenny Lum, president of the Seafood Products Association (SPA), which organized the Food Pathogen Intervention Symposium on April 27 in Seattle.

Technical Tools

The need for technical tools to combat pathogens has been bolstered in recent years by consumers’ growing demand for foods that receive minimal processing. The popularity of farmers’ markets and food cooperatives as sources of locally produced foods, as well as the burgeoning demand for organic foods, puts extra pressure on safety measures.

“There’s a recognition that for some food products out there we maybe don’t have the right interventions in place, or we didn’t recognize that we needed interventions,” Lum explained. “Non- or minimally processed foods are really our focus. We know there’s risk there that we can mitigate with intervention.”

That mitigation will focus mainly on the use of featured technologies to combat the common pathogens E. coli, Listeria, and Salmonella. “These are generally the most resistant,” said Subba Rae Gurram, SPA’s director of process technology. “We’re trying to aim at pathogens that would be logically targeted. In the process of controlling those, we’ll probably be controlling others.”

Pathogen experts are touting a smorgasbord of technical fixes.

“We’ve tried to identify things we can do to food before it’s packaged, and then things that are active in the packaging, such as lactates and diacetates, and products like irradiation and high pressure that can be used post-packaging,” Lum said. “We’ll also have a lot of discussions about hurdles technology—the idea of multiple barriers to specific food pathogens. Some of the technologies have been around for a time while others are relatively new. It’s a matter of trying to identify the applications and where they can work.”

Advances in Post-Packaging

Non-thermal post-packaging methods represent the most recent developments and improvements in intervention technologies.

Jacek Jaczynski, associate professor of food safety at West Virginia University, advocates the advantages of electron beam processing. This emerging technology has found some use in treating fruits and vegetables. It offers particular application benefit because the electrons penetrate no more than a few microns.

Research teams have recently started to apply the technology to new foods. Jaczynski has participated in studies of e-beam’s value in reducing the presence of Salmonella strains in peanut butter. They have shown, in particular, that e-beam irradiation is an effective means of killing bacteria without the application of heat. Boosting the research studies is evidence that consumers’ suspicion of any food irradiation technology is decreasing.

Errol Raghubeer, vice president of food microbiology and food technology at Avure Technology Inc. in Kent, Wash., emphasizes the growth of high-pressure processing. This technique features water under very high hydrostatic pressure to produce packaged foods that, according to Avure, “are safer, longer lasting, more natural, and better tasting.” Pasteurization systems that use pressures up to 100,000 pounds per square inch can destroy several pathogens, notably E. coli, Listeria, and Salmonella, while causing little change to the organoleptic properties and nutritional value of foods. Application areas include sliced meats, processed fruits and vegetables, fresh juices and smoothies, and delicatessen salads and dips.