Skip to main content

Growth of Listeria monocytogenes Restricted by Native Microorganisms and Other Properties of Fresh-Cut Spinach

Buy Article:

$37.00 plus tax (Refund Policy)


A study was undertaken to investigate the cause of the bacteriostatic activity of fresh-cut spinach leaves against Listeria monocytogenes. L. monocytogenes was cultivated in pure tryptic soy broth for use as a monoculture, in tryptic soy broth containing 10 mg ml−1 of autoclaved or nonautoclaved freeze-dried spinach powder, and in tryptic soy broth in mixed cultures with various microorganisms isolated from fresh-cut spinach, including Pseudomonas fluorescens biovar I, P. fluorescens biovar III, Staphylococcus xylosus, and an undefined culture of mesophilic aerobic microorganisms (MAMs) isolated from freeze-dried spinach powder. These microorganisms were inoculated at 4.4 log CFU ml−1 and L. monocytogenes was inoculated at 2.4 and 4.4 log CFU ml−1. After 24 h of incubation at 30°C, the populations of the two inoculum levels L. monocytogenes increased to 9.0 and 9.6 log CFU ml−1 in the tryptic soy broth control, to 5.4 and 7.5 in nonautoclaved spinach powder cultures, and to 8.8 and 9.1 log CFU ml−1 in autoclaved spinach powder cultures; In mixed cultures with biovar I of P. fluorescens, L. monocytogenes increased to 7.4 and 8.6 log CFU ml−1; with biovar III to 7.7 and 9.1, with S. xylosus to 7.8 and 9.2, and with the MAMs to 7.1 and 8.0 CFU ml−1 in the low and high listerial inoculum cultures respectively. The LSD(0.05) of the means were 0.5 and 0.6, respectively. The freeze-dried spinach powder had an inhibitory effect on the growth of L. monocytogenes. The inhibitory effect was greatly decreased when the native microorganisms were almost eliminated by heating or irradiation. These results indicate that if L. monocytogenes is present as a contaminant on fresh-cut spinach, its growth probably will be restricted by native microorganisms.


Document Type: Research Article

Affiliations: Horticultural Crops Quality Laboratory, Agricultural Research Service, United States Department of Agriculture, BARC-West, Beltsville, Maryland 20705-2350, USA

Publication date: August 1, 1997

More about this publication?
  • IAFP Members with personal subscriptions to JFP Online: To access full-text JFP or JMFT articles, you must sign-in in the upper-right corner using your Ingenta sign-in details (your IAFP Member Login does not apply to this website).

    The Journal of Food Protection (JFP) is a refereed monthly publication. Each issue contains scientific research and authoritative review articles reporting on a variety of topics in food science pertaining to food safety and quality. The Journal is internationally recognized as the leading publication in the field of food microbiology with a readership exceeding 11,000 scientists from 70 countries. The Journal of Food Protection is indexed in Index Medicus, Current Contents, BIOSIS, PubMed, Medline, and many others.

    Print and online subscriptions are available to IAFP Members and institutional subscribers. IAFP Members with a subscription to JFP Online will have access to all available JFP and JMFT content. Online visitors who are not IAFP Members or journal subscribers will be charged on a pay-per-view basis. Membership and subscription information is available at
  • Information for Authors
  • Submit a Paper
  • Subscribe to this Title
  • Membership Information
  • Information for Advertisers
  • ingentaconnect is not responsible for the content or availability of external websites

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more