Roumanian Biotechnological Letters Vol. 13, No. 5, supplement, 2008, pp. 49-58 Copyright © 2008 Bucharest University Printed in Romania. All rights reserved Roumanian Society of Biological Sciences ORIGINAL PAPER 49 Survival of Listeria monocytogenes in Sucuk during Manufacturing and Storage Periods at Different Modified Atmosphere Received for publication, August 28, 2008 Accepted, September 24, 2008 AYKUT BARAZI and OSMAN ERKMEN* Department of Food Engineering University of Gaziantep Faculty of Engineering, 27310 Gaziantep, Turkey *Corresponding author: Department of Food Engineering University of Gaziantep Faculty of Engineering, 27310 Gaziantep Turkey e-mail: erkmen@gantep.edu.tr Phone: 0342 3172313; Fax: 0342 3601011 Abstract The effect of manufacturing steps and storage in different modified atmosphere (MA) on L. monocytogenes in sucuk were studied. Sucuk dough was fermented for 3 days and ripened and dried with a stepwise RH and temperature reduction. The sucuks were packaged at different MA and stored at 4 o C. After 3 days of fermentation, L. monocytogenes was decreased by 0.34 and 0.32 log cfu g -1 in sucuks made with and without starter culture respectively. The decrease was continued during ripening and storage periods at different MA. MA had significant (p<0.05) effect on the survival of L. monocytogenes during storage. 100 % CO 2 and vacuum packaging provided significant (p<0.05) decrease when compared to the storage in the presence of O 2 (40 % and air). After 20 days of storage in 100 % CO 2 package, all added L. monocytogenes (6.06 log cfu g -1 ) was inactivated while 1.27 and 1.87 cfu g -1 survived in packages containing 40 % O 2 and air respectively. LAB were also reduced during 20 days of storage. pH values of sucuks were decreased during 3 days of fermentation and increased during storage periods. CO 2 in combination with low pH assists in reducing the numbers of the organism in the sucuk. Keywords: Sucuk; Modified atmosphere; Listeria monocytogenes Introduction Sucuk (Turkish dry-fermented sausage) have traditionally been produced by fermentation combined with drying without heat treatment. Sucuk is a mixture of meat, spices, salt and sodium nitrite/nitrate. Sausages are commonly eaten in sandwiches in many countries. According to the Centers for Disease Control (CDC) estimates collected through 1997, listeriosis, the food borne illness resulting from ingestion of Listeria monocytogenes, affects approximately 2,500 people annually with approximately 500 deaths (CFSPH, 2005). Although vulnerable groups typically include those with developing and compromised immune systems such as children, critically ill individuals, transplant patients, and the elderly, the affliction of pregnant women generates the largest regulatory concern due to the high percentage of maternal susceptibility to this disease and infant mortality. Consequently, most recent L. monocytogenes outbreaks have been attributed to refrigerated, ready-to-eat foods such as deli meats, including sliced ham and turkey, Mexican-style soft cheeses, and frankfurters [1, 2, 3, 4]. Food safety has become an increasingly important issue for the meat industry, and improved control of bacterial pathogens, including L. monocytogenes, has become a high priority for regulatory agencies [5, 6]. Meat and meat products (such as minced meat, sausage) have frequently been found to be contaminated with L. monocytogenes and could serve as vehicles of this pathogenic bacteria [7, 8] and the outbreak of L. monocytogenes from contaminated