Ready-to-eat meat and poultry products pose the highest potential dangers but also represent the most impressive advancements in product safety in today’s food industry.
Even when multi-million-pound recalls of fresh ground beef were occurring with alarming regularity, regulators were targeting RTE proteins for special attention. Pathogenic E. coli frightened the public, but food safety experts knew that relatively mild thermal treatment was enough to neutralize these microbial wimps.
Listeria monocytogenes, on the other hand, is far and away the most lethal foodborne pathogen, and RTE products are a common infection avenue. A 2003 study published by the National Food Processors Association (a forerunner to Grocery Manufacturers Association) found Listeria in up to 4.7 percent of product samples, a finding made more alarming by sometimes-high cell counts.
USDA’s Food Safety and Inspection Service at the same time was forging the risk-based program for RTE protein foods that became effective in May 2006. If only sanitation protocols are used to minimize the risk of contamination in post-lethality product handling, Alternative III status is assigned, resulting in closer inspection and oversight from FSIS. Alternative II status is conferred if either a post-lethality treatment to reduce bacterial load (bactericidal) or a microbial suppression (bacteriostatic) step is applied. If both steps are applied, a processor is classified as Alternative I and is subject to the least regulatory oversight.
Immersing or spraying meat and poultry with hot water is the conventional post-cook treatment for deli logs, hams and other RTE products. Often referred to as ultra pasteurization, it’s a relatively inexpensive process but ineffective when product overlaps and can result in organoleptic deterioration. FSIS offers ultra-violet radiation as an option, although applications are limited.
Modified atmosphere packaging can have a bacteriostatic or bactericidal effect, particularly when carbon dioxide’s antimicrobial properties are part of the gas mix, and it is effective with sliced meats. But MAP costs are double those of vacuum packaging, and the gas has a bacteriostatic, or suppressant, effect, Both bacteriostatic and bactericidal interventions are necessary to secure Alternative I status, and two methods to help achieve it for sliced meats are emerging: an antimicrobial spray at the slicer and high-pressure processing.
Spraying a deli log is fairly straightforward, assuming chemical temperature and dispersal rates are monitored and recorded for efficacy. Spraying sliced meats requires integration of one vendor’s slicing machine with a spray system from another supplier.
Is that a challenge? “You can say that again,” deadpans Joseph Riemer, vice president-food business development at Sono-Tek Corp., Milton, N.Y. Nonetheless, the spray nozzle manufacturer has integrated its ultra-sonic system with multiple slicer-manufacturers’ machines and has four systems in commercial production. One is in a meat plant in Spain; the other three found a home in the Richmond, Utah, base of Lower Foods Inc.
“We’re pretty excited about it,” enthuses president Alan Lower, whose firm has sprayed antimicrobial agents in whole-muscle bags “for years and years.” When technology for sliced deli meat became available, Lower Foods didn’t hesitate. Sono-Tek’s first system was incorporated with a Titan slicer on a new line in the fall, with two additional installations following.
“The Sono people are perfectionists,” adds Lower. “It hasn’t skipped a beat.”
In validation tests performed in October, sufficient log reduction to demonstrate effectiveness was achieved using lauric arginate (LAE) from A&B ingredients. Concentrations were above the 50 ppm threshold to qualify as a processing aid. Lower Foods is trying to establish efficacy at 44 ppm, which would exempt products from listing LAE on labels.
FSIS permits two dozen antimicrobials in direct contact with RTE foods, half of which can be considered processing aids that do not require label disclosure. Precise dosing and coverage are necessary for effectiveness, and that’s impossible to achieve with air nozzles, according to Riemer. With ultra-sonic spraying, 50,000 electronic signals per second cause the nozzle tip to vibrate, eliminating pressure from the equation and resulting in tighter uniformity in droplet size. The result is consistent dosing of up to 1,000 slices per minute.
A similar sliced-meat system from Spraying Systems Co. debuted early last year, complementing the Wheaton, Ill., firm’s decade-old RTE interventions for whole meats, according to Josh DeVoll, director-market solutions. The company provided input to FSIS when the risk-assessment hierarchy was being developed, he adds, which is why its SLIC (Sprayed Lethality in Container) line predates the 2006 final rule.
Before the sliced-meat system was developed, Spraying Systems enjoyed success with whole muscle and other bagged RTE meats. An antimicrobial spritz could be introduced either into a preformed bag or on rollstock prior to bag forming. When a vacuum is pulled prior to sealing, the antimicrobial agent is evenly distributed, providing the desired bactericidal or bacteriostatic effect.