“This process greatly decreases the time required to achieve even distribution of the ingredients in the solution, compared to earlier immersion or marination methods, particularly for larger cuts of meat,” says Lynn Knipe, extension processed meats specialist at The Ohio State University.

Traditionally, injection has been used to make products like ham or bacon by infusing a brine or curing solution into the center of the cuts. More recently, brine solutions — primarily salt and water, but no nitrite — have been added to whole-muscle cuts at lower levels to improve the juiciness of the cuts that contain less marbling. These products are referred to as “enhanced.”

“I first saw this process applied to pork loins, in response to chefs’ complaints of dry pork loins and chops from our leaner, less-marbled pork,” Knipe says, “but leaner, less tender beef cuts are also being enhanced.”

Knipe notes that the speed of injection equipment has increased in recent years to match the demands for increased throughput. However, as the speed of conveying the meat through an injector is increased, the injection pressure has to be increased as well in order to meet the same injection target. Increasing the pressure comes with its own set of challenges, he says.

“Increasing the injection pressure can result in other quality and injection uniformity problems, particularly with smaller cuts of meat,” says Knipe.

He added that injections that contain inorganic phosphates pose an environmental hazard when they are flushed through the wastewater system.

Along with the injector itself, a full line of other equipment has been developed to complement the machine, says Glen Meskimen, president of GHM and Associates, a meat industry consulting firm. That list includes mixing stations or tanks that can mix large amounts of the solutions and pumping systems to move those solutions into holding vats prior to being pumped into the injection machines.

“Technology has trained the meat processor that temperatures are of critical importance, so the mixing tanks, holding tanks and injection areas must be kept to a constant chilled temperature based upon the meat protein you are using, as well as the injection levels you are pumping at,” Meskimen says.

The size of the needle is dependent on the size and type of needle that is being run through the injector. Meskimen points out that replacing worn or bent needles assures the highest injection efficiency.

“The needles, along with the temperature of the solution, the filtering of the particulates from your solution being used, and the speed of the injection bed are important to allow the producer to manufacture the best product possible,” he adds.

Knipe adds that along with the size, the number and spacing of needles, combined with pump pressure will determine the machine’s ability to reach the target injection level and maximize the uniformity of the brine distribution.

“For example, a larger number of smaller, closely spaced needles will allow for better solution distribution in the meat and will allow for lower pump pressures to achieve the targeted injection level,” he says.

Food safety focus

As with other areas of the meat-processing plant, meat injection has become a critical area for food safety. It became a particular focus in late 2009, when almost 250,000 pounds of non-intact beef products were recalled due to an outbreak of E. coli-related illness. While those products were blade-tenderized prior to being further processed, it still raised the possibility of translocating pathogens — that a pathogen on the surface of the meat could be pushed into the center of the cut by a knife or a needle, making it harder to kill when it is cooked.

“Since the needles are entering the meat muscle, it makes it of vital importance that the sanitation crew is informed on how to assemble and disassemble the machine for a thorough cleaning,” notes Meskimen. “They must ensure that the needles are blown free of any meat protein particulate and set the needles in a sanitizing solution until they are to be used. It is also vital that the side holes of the needles are free and open to allow the spray action that distributes the solution you are pumping into the product to be pumped evenly.”

Knipe says that many processors are applying organic acid rinses to the meat cuts prior to the injection process, to eliminate the surface contamination and the chance that a pathogen may be pushed deeper into the cut during the injection process.

“Another partial solution to this challenge is to avoid recycling brine or curing solutions that run off meat cuts during the injection process,” he adds.

Injection equipment will continue to walk the fine line between speed and quality — producing quality products at ever-increasing rates, but doing so in such a way to preserve food quality and food safety. Future developments in injection will likely help give processors the quality they need at the speed that they want.

Knipe notes that there are other improvements that could yet be made, “to reduce the amount of brine that is wasted or not used, either because of the amount of brine that is needed to prime the injector pumps or the brine that is not recycled because of inadequate filtration systems.”