Effective survival of immobilized Lactobacillus casei during ripening and heat treatment of probiotic dry-fermented sausages and investigation of the microbial dynamics

• Published in: Meat science 2014-02, Vol.96 (2), p.948-955
• Main Authors: Sidira, Marianthi, Karapetsas, Athanasios, Galanis, Alex, Kanellaki, Maria, Kourkoutas, Yiannis
• Format: Article
• Language: English
• Subjects: Cells, Immobilized; Chemical Phenomena; Colony Count, Microbial; Dry-fermented sausages; Enterobacteriaceae - isolation & purification; Fermentation; Food Contamination - prevention & control; Food Handling - methods; Food Microbiology; Hot Temperature; Humans; L. casei ATCC 393; Lactobacillus - isolation & purification; Meat Products - analysis; Meat Products - microbiology; Multiplex PCR; PCR-DGGE; Polymerase Chain Reaction; Probiotics; Probiotics - metabolism; Pseudomonas - isolation & purification; Staphylococcus - isolation & purification; Taste
• ISSN: 0309-1740; 1873-4138
• DOI: 10.1016/j.meatsci.2013.09.013

The aim was the assessment of immobilized Lactobacillus casei ATCC 393 on wheat in the production of probiotic dry-fermented sausages and the investigation of the microbial dynamics. For comparison, sausages containing either free L. casei ATCC 393 or no starter culture were also prepared. During ripening, the numbers of lactobacilli exceeded 7logcfu/g, while a drastic decrease was observed in enterobacteria, staphylococci and pseudomonas counts. Microbial diversity was further studied applying a PCR-DGGE protocol. Members of Lactobacillus, Leuconostoc, Lactococcus, Carnobacterium, Brochothrix, Bacillus and Debaryomyces were the main microbial populations detected. Microbiological and strain-specific multiplex PCR analysis confirmed that the levels of L. casei ATCC 393 in the samples after 66days of ripening were above the minimum concentration for conferring a probiotic effect (≥6logcfu/g). However, after heat treatment, this strain was detected at the above levels, only in sausages containing immobilized cells. •Immobilized L. casei survived during ripening of probiotic dry-fermented sausages.•The efficacy of cell immobilization during the heating process was assessed.•Microbial dynamics was studied applying both plating and PCR-DGGE analysis.