Salmonella treatment minimizes liabilities - trisodium phosphate

Prepared Foods, Feb, 1993

The chicken industry produces one of the most popular and healthful sources of protein in our diet. Now, the pesky salmonella cloud is about to be lifted.

Although modern, sanitary processing facilities and techniques have considerably reduced bacteria levels in chicken carcasses before they leave the plant, salmonella incidence levels of 10% to 40% are still common, according to U.S. Dept. of Agriculture reports.

The U.S. Dept. of Agriculture has just approved the use of AvGard trisodium phosphate (TSP) from Rhone-Poulenc Food Ingredients, Cranbury, N.J., to significantly reduce, although not eliminate, the incidence of salmonella and other food-borne pathogens such as E. coli and campylobacter on poultry.

It promises to have a singular affect on poultry quality nationwide, explains Bill Swartz, Rhone-Poulenc's director of technology.

"During our testing phase, we only found one bird that tested positive for salmonella out of 250 birds that were randomly picked out of a million-bird production run," says Swartz.

"In addition, E. coli populations were reduced to less than 10 colony-forming units per milliliter."

But there is one more factor that played an important role in obtaining government approval for the ingredient:

Says Swartz: "A very strong advantage to using TSP is that it does not affect spoilage bacteria. Consequently, the spoilage bacteria can still behave as markers of poultry freshness, unlike some other technologies that have been proposed."

The process is neither expensive nor complicated. Using specially developed application equipment, birds are immersed for a few seconds in a solution of TSP near the end of the production operation.

"The technology does require the addition of a separate dipping tank made of stainless steel as chilling tanks are normally made of aluminum, which TSP will corrode," allows Swartz. It is also much more cost-effective to have a separate tank as poultry chilling requires close to 1/2-gallon of water per bird. Consequently, incorporating TSP directly into the chilling water would be cost-prohibitive.

Subsequent processing or packaging steps and batter/breading adhesion characteristics are unaffected by the trisodium phosphate.

"Tests conducted at Pennsylvania State Sensory Laboratories confirmed that there is no difference in taste, appearance, and texture between the treated and untreated chickens in either raw, baked or fried form," says Swartz.

Precisely how the treatment lowers surface salmonella contamination has not been determined. However, Rhone-Poulenc scientists speculate that the process, at least in part, works by removing a fat coating on poultry, allowing the salmonella to be washed from the surface of the bird more effectively.

Rhone-Poulenc is in the process of licensing the patented technology to interested poultry producers. The company estimates that the processing costs of using Avgard will amount to less than $0.01 per bird.

Trisodium phosphate, a common, GRAS-approved orthophosphate, is widely used in processed cheese, breakfast cereals and other popular foods. Rhone-Poulenc reports that the amount of AvGard TSP that remains on the bird after processing is so low that TSP qualifies as a processing aid and need not appear on the ingredient label.