HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Interpretive Summary Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Neugebauer, K. A. Articles by Gilliland, S. E. Search for Related Content PubMed PubMed Citation Articles by Neugebauer, K. A. Articles by Gilliland, S. E.

Antagonistic Action of Lactobacillus delbrueckii ssp. lactis RM2-5 Toward Spoilage Organisms in Cottage Cheese^*

K. A. Neugebauer and S. E. Gilliland

Department of Animal Science and Food and Agricultural Products Center Oklahoma State University, Stillwater 74078-6055

Corresponding author: S. E. Gilliland; e-mail: seg{at}okstate.edu.

Cells of Lactobacillus delbrueckii ssp. lactis RM2-5 were added to cottage cheese stored at 7°C in different amounts to determine if they would inhibit the growth of Pseudomonas fluorescens, also inoculated into the cheese samples. In addition, experiments were conducted in which no spoilage organisms were added to determine the effect of the lactobacilli on the natural background flora in the cottage cheese. For most experiments, as the numbers of lactobacilli increased, the numbers of spoilage organisms were lower than in the control on any given day of storage. In cheese inoculated with P. fluorescens, the numbers of spoilage organisms in the control had increased 5 log cycles by d 7, whereas the treatment containing the highest level of L. delbrueckii ssp. lactis RM2-5 (1.0 x 10⁹ cfu/g) had not, and did not, increase over the course of the 21-d study. In the experiments where no spoilage organisms were added, lactobacilli significantly retarded the growth of gram-negative bacteria in the cheese. However, in these experiments, mold growth on the samples became a limiting factor during extended storage. The results of these experiments indicate that lactobacilli could be effective at helping control gram-negative spoilage bacteria in cottage cheese, thus potentially extending its shelf life.

Key Words: Lactobacillus delbrueckii ssp. lactis • cottage cheese • psychrotrophic spoilage

Abbreviation key: CVT = crystal violet tetrazolium chloride, LBS = lactobacillus selection, MRS = de Man, Rogosa, Sharpe.