CERELA   05438
CENTRO DE REFERENCIA PARA LACTOBACILOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Lactobacillus sakei CRL1862 improves safety and protein hydrolysis in meat systems
Autor/es:
CASTELLANO P; M. ARISTOY; M. A. SENTANDREU; VIGNOLO G; F. TOLDRÁ.
Reunión:
Congreso; Microal 2012; 2012
Resumen:
Fresh meat and their fermented and processed products provides an excellent environment for the growth of pathogenic and spoilage organisms. The presence of the emergent food poisoning Listeria monocytogenes, Staphylococcus aureus and Escherichia coli O157:H7 during manufacturing has increased the awareness in the general public opinion demanding pathogen-free foods with minimal processing, fewer chemical preservatives, high nutritional value, and intact sensory quality. This last issue, particularly taste and aroma is known to be highly enhanced through the hydrolysis of meat proteins by LAB during fermentation with the release of small peptides and amino acids. In fermented sausages, inactivation of pathogens such as L. monocytogenes and S. aureus proved to be highly competitive by bacteriocinogenic LAB while protein changes is highly dependent on the hydrolytic capacity of the strains used as starter cultures. In view to be used as competitive starter culture during meat fermentation, the ability of Lactobacillus sakei CRL1862 (isolated from cooked sausages) for pathogen control, sarcoplasmic and myofibrillar proteins degradation in pork meat systems as well as the inability for biogenic amines formation and antibiotic susceptibility were evaluated. Bacteriocin-producing L. sakei CRL1862 showed bactericide and bacteriostatic effect against L. monocytogenes and S. aureus, respectively in a beaker sausage assay during 9 days of storage at 22 ºC. The hydrolytic effect of this strain on protein extracts was evaluated by SDS-PAGE and r-HPLC. A more pronounced proteolysis was evidenced in inoculated sarcoplasmic proteins compared to myofibrillar extracts with the generation of predominantly hydrophilic peptides and the increase of total free amino acids concentration. L. sakei CRL1862 produced neither histamine nor tyrosine and exhibited no resistance to the assayed antibiotics. In conclusion, L. sakei CRL1862 effectively controlled the growth of L. monocytogenes and Staph. aureus and was able to hydrolyze pork meat extracts generating peptides and amino acids, which may improve hygienic and sensorial attributes of fermented meat products.