《NIsi玉米淀粉抗菌》.pdfVIP

ARTICLE IN PRESS FOOD MICROBIOLOGY Food Microbiology 22 2005 93–99 www.elsevier.nl/locate/jnlabr/yfmic Antimicrobial activity of nisin-adsorbed silica and corn starch powders a, c b a P.L. Dawson *, L. Harmon , A. Sotthibandhu , I.Y. Han a Department of Food Science and Human Nutrition, Clemson University, A203J Poole Hall, SC 29634-0371, Clemson, South Carolina, USA b South Carolina Governors School for Science and Mathematics, Hartsville, South Carolina, USA c Food Science and Nutrition, Faculty of Science, Srinakharinwirot University, Sukumvit 23, Bangkok, Thailand Received 17 November 2003; received in revised form 27 March 2004; accepted 6 April 2004 Abstract The antimicrobial peptide nisin is an effective bacterial inhibitor and has been adsorbed onto various surfaces and added to packaging ?lms. In the present study, nisin was adsorbed onto food-grade powders then evaluated for nisin activity in a series of three experiments. Adsorbent powders used were calcined diatomaceous earth, synthetic calcium silicate, hydrate, two diatomaceous earth, and corn starch powders. Adsorption was conducted by placing the powders in agitated nisin solutions, followed by dehydration of the powder pellet after centrifugation. The dehydrated powders were then tested for inhibitory activity against either Lactobacillus plantarum or Listeria monocytogenes. Activity was measured by placing the nisin-adsorbed powders in solutions of 0.1% peptone water inoculated with one of the test bacterial strains. Cel-pure 65 adsorbed then released from 74.7% to 94.7% of the nisin activity contained in the original solution 500–800 IU/ml in which the powders were agitated. Corn starch adsorbed then released from 45.4% to 60.5% of nisin activity when from 300 to 700 IU/ml nisin activity adsorbing solutions were utilized. One percent of nisin-absorbed Celpure 100 and Celpure 65 powders in 30 ml of log 4.5 cfu/ml L. monocytogenes