AUTOCHTHONOUS LACTIC ACID BACTERIA FOR THE BIOPRESERVATION OF MEAT PRODUCTS

HERMAN, CRISTIAN; IBAÑEZ, R.; GARRO O.A.; VIGNOLO G.M.; CAYRÉ, M.E.; CASTRO M.

CAMPINAS

Simposio; 12th SLACA. Latin American Symposium of Food Science; 2017

Facultad de Engenharia de Alimentos (FEA) - UNicamp

Lactic acid bacteria isolated from artisanal meat products were evaluated for their potential application as protective cultures in cooked meat products (CMP). 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. Strains selected (104 CFU/g) were co-inoculated with L. innocua or S. aureus (102 -103 CFU/g) into sterilized 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 (sausages). Besides, general appearance, aroma, color, and tactile texture of meat samples inoculated with SBS were analyzed by a quantitative sensory analysis. In both trials, samples were vacuum-packaged and stored at 5°C for 4 weeks. The strains L. sakei ACU-16 and L. curvatus ACU-21 showed the best performance and were individually applied as CMP protective cultures. In control systems, inoculated microorganisms grew exponentially during storage reaching 6.93±0.11 log CFU/g for S. aureus and 6.87±0.4 CFU/g for L. innocua. However, in the presence of each SBS, S. aureus counts did not show significant differences compared to the initial values while L. innocua counts significantly decreased giving 1.2 (L. sakei ACU-16) and 1.7 (L. curvatus ACU-21) logarithmic cycle reduction. Moreover, in naturally contaminated samples they delayed Brochothrix thermosphacta and Enterobacteriaceae spp. growth along refrigerated storage. Regarding sensory attributes, aroma was the most variable one along storage. Panelists detected an increase in acidic odor and the accumulation of exudate in inoculated and control samples; nevertheless, no significant differences were detected between them. Summarizing, results showed that both SBS had bacteriostatic and bactericidal effects against target bacteria. Moreover, there is early evidence that incorporating them onto a CMP would not significantly modify certain sensory attributes.