VALIDATION OF THE EFFECT OF INTERVENTIONS AND PROCESSES ON PERSISTENCE OF PATHOGENS ON FOODS
Location: Food Safety and Intervention Technologies
Title: FATE OF LISTERIA MONOCYTOGENES AND ESCHERICHIA COLI O157:H7 IN SOUDJOUK-STYLE FERMENTED SEMIDRY SAUSAGE
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: February 22, 2006
Publication Date: August 13, 2006
Citation: Porto Fett, A.C., Hwang, C., Juneja, V.K., Ingham, S.C., Ingham, B.H., Buege, D.R., Luchansky, J.B. 2006. Fate of listeria monocytogenes and escherichia coli o157:h7 in soudjouk-style fermented semidry sausage. [Abstract] Internatinal Association for Food Protection's Annual Meeting P1-30. pg. 102.
All-beef (20% fat) raw Soudjouk batter containing dextrose (0.25 or 0.60%), spices, and a commercial pediococcal starter culture was inoculated with a five-strain mixture of Listeria monocytogenes or a three-strain mixture of Escherichia coli O157:H7 to a level of ca. 6.0 log10 CFU/g. Sausages were transferred to an environmentally-controlled incubator with an air flow of 1.0 to 1.5 m/s, hung vertically, and fermented at 24 degrees C with a relative humidity (RH) of 90-95% for 72 h and then dried at 22 degrees C for an additional 72 h with 80-85% RH. After the fermentation and drying steps, sausages were vacuum-packaged in bags and stored at 4 degrees, 10 degrees, or 21 degrees C for up 30 days. The addition of 0.25% or 0.60% of dextrose to the batter decreased the pH values from ca. pH 5.8 to pH 5.2 and pH 4.8, respectively, after fermentation and drying. Fermentation and drying alone reduced the numbers of L. monocytogenes by 0.07 and 1.03 log10 CFU/g for sausages fermented to pH 5.2 and pH 4.8, respectively, whereas the numbers of E. coli O157:H7 decreased by 0.27 and 1.11 log10 CFU/g, respectively. When sausages fermented to pH 5.2 or 4.8 were stored at 4 degrees, 10 degrees or 21 degrees C for up 30 days, the numbers of L. monocytogenes decreased by 0.2, 0.7 and 0.2 and 0.7, 0.1 and 1.3 log10 CFU/g, respectively. When sausages inoculated with E. coli were fermented to pH 5.2 or 4.8 and stored at 4 degrees, 10 degrees or 21 degrees C for up 30 days, pathogen numbers decreased by 1.0, 0.6, and 3.0 and 1.8, 2.2 and 3.2 log10 CFU/g, respectively. Fermentation to pH 4.8 and storage at 21 degrees C was most effective process for reducing the numbers of both pathogens. Thus, these findings may be useful for the development of intervention strategies to control L. monocytogenes and/or E. coli O157:H7 in Soudjouk-style sausage.