fa بررسی امکان استفاده از کیتوزان به عنوان یک نگهدارنده طبیعی در سس مایونز عمومی Ggeneral پژوهشي Research Chitosan, a deacetylated derivative of chitin, is found in crustacean, arthropod, shell fish and shrimp shell as well as cell walls of some fungi . The objective of this research was to investigate the antimicrobial property of chitosan and possibility of its use as a natural preservative in mayonnaise. In this study, chitosan was produced by chemical method from shrimp shell. The antimicrobial activities of chitosan against <em>Salmonella enteritidis</em> and <em>Lactobacillus plantarum</em> were explored by calculation of the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) in media supplemented with 0.1, 0.2 , 0.3, ..., 0.9 , 1 mg/ml chitosan adjusted to pH 5 or 6 . The MIC and MBC of chitosan differed with pH and bacterial type, ranging from 0.4 to 1 mg/ml. Antibacterial activity of chitosan was inversely affected by pH, with higher activity at lower pH value. The sauce containing 0.1, 0.2 or 0.3% chitosan was inoculated with 10⁶ CFU/gr <em>S. enteritidis</em> or <em>L. plantarum</em> and stored at 5<span style="FONT-SIZE: 12pt FONT-FAMILY: ">°C</span> and 25<span style="FONT-SIZE: 12pt FONT-FAMILY: ">°C</span> for 8 days. The inhibitory effect of chitosan concentration was increased from 0.1 to 0.3%. This investigation demonstrated that 0.2% chitosan can be used in mayonnaise as a new preservative. کیتوزان، کیتین، ماده نگهدارنده، سس مایونز Chitosan, Chitin, Preservative, Mayonnaise. 361 370 http://jstnar.iut.ac.ir/browse.php?a_code=A-10-2-843&slc_lang=fa&sid=1 H. Barzegar حسن برزگر Yes A. Karbassi احمد کرباسی No J. Jamalian جلال جمالیان No M. Aminlari محمود امین لاری No