Food safety research focuses on technologies to improve process control and product quality.
Ice-Water Slurry for Poultry Chilling
Poultry processors in North America typically use water immersion chilling systems to lower the temperature of carcasses to a degree that inhibits pathogen growth. They also add an antimicrobial agent to the water as an extra safeguard. These necessary precautions use considerable amounts of water, energy, and antimicrobials.
ATRP researchers are investigating the feasibility of using ice-water slurry (a mixture of tiny ice crystals and liquid water) as an alternative chilling medium both for its increased cooling capacity and antimicrobial properties.
Initial investigations showed that ice slurry carcasses’ core temperatures decreased on average an additional 25 percent in degrees Celsius compared with chilled water carcasses in 45-minute trials. In terms of microbial reduction, results showed ice slurry had an overall reduction of 1.2 log compared with a chilled water reduction of 0.6 log. Researchers hypothesize that the ice slurry’s grain acts as a scrub on the external surface of the carcass, dislodging or eroding skin-attached pathogens and releasing them directly into the chiller’s water. This direct abrasion could possibly reduce bacterial loads and lower the amount of antimicrobials needed.
Current work is focused on the ice slurry’s viability as it relates to salt management (salt is used as a freezing point depressant). Recent tests investigated salt uptake tendencies. Researchers found that salt uptake tends to be constrained to the skin without significant penetration into muscle tissue. More investigation is underway, with a focus on determining if salt concentration in the slurry has any effect on PAA (peracetic acid) efficacy as well as product labeling implications based on current regulations imposed by the U.S. Department of Agriculture’s Food Safety and Inspection Service (FSIS).