Autochthonous lactic acid bacteria for the biopreservation of meat products

HERMAN, C.; GARRO, O.; VIGNOLO, G.; CAYRÉ, M E; CASTRO, M.

Campinas

Simposio; Simpósio Latino Americano de Ciência de Alimentos (SLACA); 2017

Faculdade de Engenharia de Alimentos da Universidade Estadual de Campinas

Lactic acid bacteria isolated from artisanal meat products were evaluated for their potential application as protective cultures in cooked meat products (CMP). Isolated strains were examined for antimicrobial activity against various pathogenic and spoilage bacteria. Those strains which were homofermentative, non-exopolysaccharide producers, bacteriocinogenic-like and able to inhibit Listeria spp. and Staphylococcus aureus were selected and genetically identified by 16S rDNA sequencing. Subsequently, identified strains were studied for the ability to grow and produce bacteriocin like substances (BLIS) at different environmental conditions from CMP. Strains best adapted to these conditions were then examined for basic safety properties such as antibiotic resistance and aminoacid decarboxylation activity. Strains selected on the basis of theseproperties were co-inoculated with L. innocua and S. aureus into sterilyzed cooked sausages to evaluate their protective effect. Once this effect was checked, naturally contaminated samples were inoculated with the selected bacteriocinogenic strains (SBS) to evaluate their protective effect on the indigenous flora of CMP. Besides, organoleptic characteristics of the meat samples with SBS were analyzed by a quantitative sensory analyses. In both trials, samples were vacuum packaged and stored at 5°C. From the pool of originally isolated strains (253 strains), nine were selected at a first instance and identified as Lactobacillus sakei (7 strains) and L. curvatus (2strains). Among these strains, only 4 were able to produce BLIS at meat environmental conditions,showing 2 of them -L. sakei ACU-16 and L. curvatus ACU-21- the best performance. Finally, when these last two strains were applied as protective cultures in cooked meat sausages, a bactericidal and bacteriostatic effect against L. innocua and S. aureus, respectively, was observed alongstorage. Moreover, they delayed Brochothrix thermosphacta and Enterobacteriaceae spp. growth rates along refrigerated storage. Additionally, these two SBS showed no detrimental effect on sensorial parameters related to spoilage of the cooked sausages.