Cool Chemistry: PAA’s Shelf Life in the Chiller

Peracetic acid is everywhere in a poultry processing plant, but very few people know what is really happening to it inside the chiller. In this episode of Unplucked, host Andy Vance talks with Georgia Tech Research Institute scientists Daniel Sabo and Stephanie Richter about the chemistry behind one of the industry’s most important antimicrobials and why understanding its decay is key to food safety, product quality, and cost control. They unpack how PAA is used throughout the plant, from immersion chillers to cleanup, and explain why plants began seeing puzzling swings in concentration that could not be explained by dosage alone. To solve the mystery, the team spent long days in multiple plants mapping chillers from startup to shutdown, then recreated those conditions in the lab to study how pH, temperature, total dissolved solids, fats, oils, and proteins alter PAA’s half-life and stability.   Listeners get an accessible tour of “decay kinetics” and practical measurement challenges. Daniel and Stephanie explain why you never directly measure PAA, how titration kits and DPD colorimetric meters work, and how human error and sampling timing can skew readings. They share what surprised them most in the data, including the outsized role of total dissolved solids, the way combinations of components overwhelm stabilizers, and the finding that once a chiller reaches a certain “steady state,” its water chemistry can stay remarkably stable through a shift. The conversation then turns to solutions, from managing pH and solids to exploring tiny doses of food-grade additives that can extend PAA half-life by 8 to 10 times without hurting antimicrobial efficacy or bleaching product. Along the way, the guests highlight the value of deep, applied collaboration between industry and academia, showing how processor questions can spark research that pays off in safer plants, better looking product, and smarter use of chemistry across the protein sector.   CREDITS Host - Andy Vance Producer - Lyndsey Johnson Audio Editor & Engineer - Michael Lunt   LEGAL The information provided in this episode of Unplucked is for informational and educational purposes only and should not be considered professional advice. While we discuss scientific research, public health, and industry practices, this podcast does not substitute for advice from qualified industry and scientific professionals. The views expressed in this episode are solely those of the host and guests and do not necessarily reflect the official opinions of The Poultry Science Association, their respective affiliates, or employees.