CERELA   05438
CENTRO DE REFERENCIA PARA LACTOBACILOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
MEAT PROTEIN DEGRADATION BY TWO DIFFERENT AUTOCHTHONOUS STARTER CULTURES IN A LOW SALT DRY FERMENTED SAUSAGE MODEL
Autor/es:
DE ALMEIDA, M; BONACINA, J; SAAVEDRA L; CONTRERAS CASTILLO, C; FADDA S
Reunión:
Simposio; SAMIGE; 2014
Resumen:
Fermented sausages have a relatively long shelf life; its microbiological quality is guaranteed by the fermentation carried out by lactic acid bacteria (LAB). However it is a product with high levels of sodium so it is not suitable for people with hypertension or cardiovascular diseases. There exist many technological difficulties in reducing the concentration of salt, because sodium chloride promotes microbiological stability and contributes to flavor formation. The objective of this work was to evaluate the behavior of two different LAB strains to be applied as starter culture in fermented sausage production with reduced sodium contents (1%), focusing on its proteolytic potential towards meat proteins. The presence of LAB with optimal peptidase activities guarantees the production of flavor peptides and amino acids that would balance flavor development in low sodium-fermented sausages. An in vitro Beaker Sausage model was used for this purpose. Ground meat with additives was divided into three batches and incubated at 22°C: (T1) Lactobacillus curvatus CRL 705/ Staphylococcus vitulinus GV 318; (T2) Lactobacillus sakei CRL1862/ Staphylococcus vitulinus GV 318 and (T3) un-inoculated Control with antibiotics. Analysis of pH and bacterial counts on differential agar media was performed at 0, 3, 6 and 10 days. Total Protein was analyzed by Bradford and the proteolysis was evaluated by Tricine-SDS-PAGE (sodium dodecyl sulfate, polyacrylamide electrophoresis) at 0 and 10 days. Results showed that Lactobacillus curvatus (T1) counts remained stable (8 log CFU/ml) and Staphylococcus vitulinus decreased 3 logs after 10 days of incubation. The pH decreased rapidly from 5.8 to around 4.7 at the 10th day for both strains (T1 and T2), due to the acidogenic metabolism of LAB. On the other hand, Lactobacillus sakei CRL1862 (T2) showed a slight decrease after 10 days whereas the acidic environment resulted in the inhibition of Staphylococcus vitulinus in both batches. The proteolytic activity after 10 days of incubation, T2 (L. sakei CRL 1862) showed a more intense meat protein degradation profiles than T1 (L. curvatus CRL705). A similar tendency was observed in total protein contents, where T2 showed slight higher drop in this parameter (T0: 7.65 mg/ml; T10days: 4.10 mg/ml) than T1 (T0: 6.67 mg/ml; T10 days: 4.70 mg/ml). With respect to amino acids analysis, T1 and T2 beaker sausages, demonstrated high amino acid enrichment after 10 days. In fact, beaker sausages inoculated with L. sakei CRL1862 and L. curvatus CRL705 increased 7 and 6 times amino acid contents of the meat system respectively. In conclusion, the both assayed starter culture have showed an appropriate growth performance on Beaker Sausage model with reduced NaCl contents, optimal pH drop and ability to hydrolyze meat proteins. Lactobacillus sakei CRL1862 + Staphylococcus vitulinus GV 318 having the most efficient performance, can be proposed as a candidate for the production of low-sodium fermented sausages.