Use of Capillary Tubes and Plate Heat Exchanger to Validate U.S. Department of Agriculture Pasteurization Protocols for Elimination of Salmonella Enteritidis from Liquid Egg Products

Abstract

D values for a five-strain cocktail of Salmonella Enteritidis in five different liquid egg products (whole egg, egg yolk, egg white, egg yolk + 5% sucrose + 5% NaCl, and egg yolk + 10% NaCl) were determined using 100-μl capillary tubes. The egg products were inoculated with approximately 1 × 1010 organisms/ml and heated in capillary tubes to temperatures ranging from 51 to 68°C for various time intervals. Using a pilot scale plate heat exchanger, the U.S. Department of Agriculture (USDA) protocols for pasteurization were also evaluated using egg products inoculated with approximately 1 × 107 Salmonella Enteritidis/ml. Results of experiments with capillary tubes suggested that almost all processes would result in less than the 9D process recommended by the USDA. However, when the egg products were pasteurized using the plate heat exchanger, a greater than 9D process was achieved for Salmonella Enteritidis in all products except egg yolk containing 5% sucrose + 5% NaCl, which received approximately a 4D process.