INVESTIGADORES
GARRO Oscar Alfredo
congresos y reuniones científicas
Título:
BIOPROTECTIVE CULTURE FOR COOKED MEAT PRODUCTS: EVALUATING SALTS EFFECTS
Autor/es:
HERMAN, CRISTIAN; ALVAREZ, OE; CASTRO MARCELA P.; CAYRÉ, MARÍA E.; GRACIELA VIGNOLO; GARRO, OSCAR A.
Lugar:
San Miguel de Tucuman
Reunión:
Simposio; IV International Symposium on Lactic Acid Bacteria: Food, Health and Applications; 2013
Institución organizadora:
CERELA
Resumen:
The preservation of meat products is increasingly directed towards biocontrol using
bacteriocinogenic Lactobacillus species as protective cultures to inhibit the growth of undesirable
microorganisms. However, food preservation using in situ bacteriocin production requires an
adequate knowledge of the relationship between cell growth and bacteriocin production as a
function of the intrinsic and extrinsic factors that prevail in the food matrix. The aim of this work
was to evaluate the combined effect of NaCl and NaNO2 concentrations, under refrigeration (7°C),
on the antimicrobial activity of Lactobacillus curvatus 409 a strain isolated from artisanal bologna
type sausage, which showed good properties as a bioprotective culture in cooked meat products. A
central composite design (22 + star) was applied, being the independent variables: NaCl
concentration (0.2, 1, 3, 5 and 5.8 % w/v) and NaNO2 concentration (6, 35, 105, 175 and 204 mg/L).
Cell growth was tested on MRS broth supplemented with the aforementioned additives assessing
optical density measurements at 600nm for 192 hours. Antimicrobial activity against Listeria
innocua was carried out by means of the agar well diffusion assay and expressed as arbitrary units
per ml (AU/ml). Time needed to reach the highest antimicrobial activity was used as response
variable. L. curvatus 409 was able to grow and produce antimicrobial substances under all
conditions tested. Analysis of results indicated that the linear effect of NaCl and NaNO2 had a
significant effect on response variable. An increase in salts concentrations drove to an increase in
the time necessary to reach the highest activity. Values found were in the range between 148 and
192 hours. The influence of NaNO2 resulted less pronounced when compared to NaCl. In addition,
the higher the concentrations of NaCl and NaNO2, the lower the values of maximum activity. These
values varied between a minimum of 50 UA/ml and a maximum of 400 UA/ml. The interaction
effect between NaCl and NaNO2 was significant indicating that high NaCl concentrations together
with high NaNO2 concentrations have a greater impact on time than with low NaNO2
concentrations. The results suggest that the effectiveness of L. curvatus 409 as a protective culture
for cooked meat products could be affected by NaCl and NaNO2 concentrations, additives inherent
to these products. Despite this fact, L. curvatus 409 could be a valuable additional hurdle in the
preservation of cooked meat products. Further studies have to be carried out to evaluate this strain
behavior in the control of Listeria spp in these products.