Title: Propyl Paraben Sensitizes Heat-Resistant Salmonella Enteritidis and Oranienburg to Thermal Pasteurization in Liquid Egg Albumen Author
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 13, 2010
Publication Date: August 1, 2010
Citation: Gurtler,J. 2010. Propyl Paraben Sensitizes Heat-Resistant Salmonella Enteriditis and Oranienburgy to Thermal Pasteurization in Liquid Egg Albumen [abstract].International Assn. for Food Protection (IAFP).Anaheim,CA.p.1. Technical Abstract: Introduction: The USDA, Food Safety and Inspection Service requires that liquid egg albumen (or egg white, LEW) undergo pasteurization at 56.7 C for 3.5 min prior to distribution. This process is known change the physical properties of LEW. The use of antimicrobials to sensitize salmonellae to pasteurization would be useful in reducing thermal treatment times and preserve sensitive LEW proteins. Propyl paraben (PrPa) is a non-toxic antimicrobial, occurs in nature, and has been given GRAS status by the FDA when added at levels up to 1,000 ppm. Purpose: The goal of this study was to determine the effects of propyl paraben on the thermal sensitivity of three heat-resistant strains of Salmonella in LEW. Methods: The pH of LEW was adjusted to pH 7.8 or 8.9 and PrPa was added to LEW at concentrations of 0, 125, 250, 500, and 1,000 ppm. A composite of heat-resistant Salmonella was washed and added to LEW at ca. 8 log CFU/ml. Inoculated LEW was held for two hours at 22 C, heated at 56.7 C for up to 25 min and analyzed for Salmonella. Results: When pasteurized under USDA guidelines (3.5 min at 56.7 C) without the addition of PrPa, 1.16, and 4.32 log CFU/ml Salmonella were inactivated at pH 7.8 and 8.9, respectively. The D56.7 values for Salmonella, based on the presence of 0, 125, 250, 500, and 1,000 ppm of PrPa, were 3.03, 1.05, 0.64, 0.26, and 0.13 min at pH 7.8, and 0.81, 1.02, 0.64, 0.21 and 0.09 at pH 8.9. Times necessary to achieve a 6-log reduction at pH 7.8 with 0, 125, 250, 500, and 1,000 ppm of PrPa were 18.18, 6.30, 3.84, 1.56, and 0.78 min, respectively, while at pH 8.9, times of 4.86, 6.12, 3.84, 1.26, and 0.54 min were required, respectively. Significance: Propyl paraben may be a useful antimicrobial for sensitizing Salmonella to thermal pasteurization in liquid egg albumen.