EXTENDING THE CHILLED SHELF LIFE OF VACUUM-PACKAGED GROUND BEEF USING ASCORBIC ACID, NITRITE OR SALT VELI GÖK 1 , SEMRA KAYAARDI 2 and ERSEL OBUZ 2,3 1 Faculty of Engineering Food Engineering Department Afyon Kocatepe University Afyon, Turkey 2 Faculty of Engineering Food Engineering Department Celal Bayar University Muradiye-Manisa 45140, Turkey Accepted for Publication September 18, 2007 ABSTRACT The objective of this study was to extend the shelf life of ground beef in chilled conditions. Samples were treated with 2% salt, 2% salt + 500-ppm ascorbic acid, or 2% salt + 100-ppm sodium nitrite. The control sample did not contain any additives. Protein, nitrite, moisture contents, pH, thiobarbi- turic acid (TBA) value, color attributes and microbial counts of samples were determined. Samples were vacuum packaged and stored in refrigeration, and chemical and microbial analyses were performed throughout storage. The pH of samples decreased during storage, and the sample having 2% salt and 500-ppm ascorbic acid had the greatest pH decline. TBA values generally increased (P < 0.05) with storage time. Samples having 2% salt + 500-ppm ascorbic acid had the lowest TBA value. On a given storage day, samples having 2% salt + 100-ppm sodium nitrite had lower microbial microbial count than other samples, indicating the antibacterial effect of nitrite. A significant storage time ¥ treatment interaction (P < 0.05) existed for almost all quality parameters studied. 3 Corresponding author. TEL: +90-236-2412144/221; FAX: +90-236-2412143; EMAIL: ersel.obuz@ bayar.edu.tr Journal of Muscle Foods 20 (2009) 211–226. © 2009, The Author(s) Journal compilation © 2009, Wiley Periodicals, Inc. 211