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Bacteriocin production by spray-dried lactic acid bacteria
J Silva1, A S Carvalho, P Teixeira
1Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Dr António Bernardino de Almeida, Porto4200-072, Portugal. joana@morango.esb.ucp.pt
Letters in Applied Microbiology
|February 19, 2002
Summary
Spray-drying lactic acid bacteria preserved their antagonistic activity against pathogens. Lactobacillus salivarius demonstrated the highest survival and resistance to the spray-drying and storage processes.
Area of Science:
- Food microbiology
- Bacteriocin technology
- Food preservation
Background:
- Lactic acid bacteria (LAB) produce bacteriocins, natural antimicrobials effective against foodborne pathogens.
- Spray-drying is a potential method for producing stable LAB powders for food applications.
- Evaluating the impact of spray-drying on LAB viability and antagonistic activity is crucial for product development.
Purpose of the Study:
- To assess the survival rates of three bacteriocin-producing LAB strains (Carnobacterium divergens, Lactobacillus salivarius, Lactobacillus sakei) after spray-drying.
- To determine the effect of spray-drying and subsequent storage on the antagonistic activity of these LAB strains against Listeria innocua, Listeria monocytogenes, and Staphylococcus aureus.
- To identify the LAB strain with the highest resistance to spray-drying and storage.
Main Methods:
- Bacteriocin-producing LAB strains were concentrated and spray-dried.
- Cell viability and antagonistic activity were measured before and after spray-drying.
- Samples were stored at 4°C and 18°C with 0.3% equilibrium relative humidity (ERH).
- Viability and antagonistic activity were monitored during storage.
Main Results:
- Higher survival rates were observed when spray-drying was conducted at 4°C.
- Most LAB strains retained their antagonistic activity post-spray-drying and during storage.
- Carnobacterium divergens lost its inhibitory activity against Staphylococcus aureus after drying.
- Lactobacillus salivarius exhibited the highest resistance to both spray-drying and storage.
Conclusions:
- Spray-drying is a viable process for producing dried powders of viable bacteriocin-producing LAB.
- The process and storage conditions did not significantly affect the antagonistic activity of most tested LAB strains.
- Lactobacillus salivarius is a promising candidate for large-scale production of spray-dried powders with antimicrobial properties.