Journal of Food Processing & Technology

Interaction between some probiotics and Listeria monocytogenes in fermented milk products

International Conference and Exhibition on Food Processing & Technology

November 22-24, 2012 Hyderabad International Convention Centre, India

N. F. Nasr

Accepted Abstracts: J Food Process Techno

Abstract:

Most pathogenic microorganisms are inhibited by the mixed growth with probiotics cultures. Therefore, the ability of Listeria monocytogenes to grow during fermentation of skim milk with thermophilic lactic acid bacteria was studied. The growth of Listeria monocytogenes was followed at 30?C for 48-72 hr in sterilized skim milk which inter-inoculated with approximately 3.0 x 103 c.f.u./ ml Listeria monocytogenes and 1.2-4.5 x 103 c.f.u./ml. of either Lactobacillus delbrueckii subsp. bulgaricus or Streptococcus thermophilus or a mixed culture of both. The viability of the pathogen in fermented milk varied with the species of lactic acid bacterium used in fermentation. The pathogen frequently survived for 24 hr in milk fermented with Lactobacillus delbrueckii subsp. bulgaricus alone and for 48 hr in milk fermented with Streptococcus thermophilus alone. It could be concluded that, mixed lactic culture has inhibition effect to L. monocytogenes higher than Streptococcus thermophilus alone. A high inhibitory effect for Lactobacillus delbrueckii subsp. bulgaricus that equal to the mixed culture was observed in the associative growth.

Biography :

Nasr Fawzy Nasr has completed his Ph.D. at the age of 35 years from Cairo University. He is Lecturer in Agricultural Microbiology Dept., Faculty of Agriculture, Cairo University and member in Egyptian Society of Applied Microbiology (ESAP). He has published 8 papers in international journals, taught several courses of microbiology in Cairo University and Helwan university and trained undergraduate and postgraduate students (different nationalities) in microbiological analysis, food safety, quality control and quality assurance.