Pathogens quantification in sausage with starter culture | Cuantificación de patógenos en embutido fermentado con cultivo iniciador

Inglés. Pathogens quantification in sausage with starter culture To evaluate the ability of Lactobacillus acidophilus LA16 as starter to inhibit the growth of Escherichia coli and Staphylococcus aureus in a fermented sausage, the pathogens were inoculated in the model meat system and in chorizo. Each pathogen was quantified and four inactivation models were evaluated to obtain the best fit. To validate the model, different variants of chorizo were prepared with or without starter. Pathogens were inoculated at concentration of 103 UFC/g CFU/g and the starter culture at 104 UFC/g CFU/g. The reduction of 2.5 log CFU/g observed in the pathogens occurred between three and six days for the variants with L. acidophilus and between seven and eight days for the variants without starter. This behavior was described by the biphasic model and it could be used to quantify Escherichia coli and S. aureus in chorizo. Keywords: starter, pathogens, fermented sausage chorizo type, modeling non- thermal inactivation.

Español; castellano. Para evaluar la capacidad del cultivo iniciador Lactobacillus acidophilus LA16 de inhibir el crecimiento de Escherichia coli spp. y Staphylococcus aureus en un embutido fermentado, se inocularon los patógenos en sistema cárnico modelo y en embutido tipo chorizo. Se cuantificó cada patógeno y se evaluaron cuatro modelos de inactivación para obtener el de mejor ajuste. Para validarlo, se prepararon diferentes variantes de chorizo con y sin cultivo iniciador. Los patógenos se inocularon a concentración inicial de 103 UFC/g y el cultivo iniciador a 104 UFC/g. La reducción de 2,5 log UFC/g observada en los patógenos ocurrió entre los tres y seis días para las variantes con L. acidophilus adicionado y entre los siete y ocho días para las variantes sin cultivo iniciador. Para el chorizo, este comportamiento fue descrito por el modelo bifásico que podría ser empleado para cuantificar E. coli y S. aureus. Palabras clave: cultivo iniciador, patógenos, chorizo, modelos de inactivación no térmica. ABSTRACT Pathogens quantification in sausage with starter culture To evaluate the ability of Lactobacillus acidophilus LA16 as starter to inhibit the growth of Escherichia coli and Staphylococcus aureus in a fermented sausage, the pathogens were inoculated in the model meat system and in chorizo. Each pathogen was quantified and four inactivation models were evaluated to obtain the best fit. To validate the model, different variants of chorizo were prepared with or without starter. Pathogens were inoculated at concentration of 103 UFC/g CFU/g and the starter culture at 104 UFC/g CFU/g. The reduction of 2.5 log CFU/g observed in the pathogens occurred between three and six days for the variants with L. acidophilus and between seven and eight days for the variants without starter. This behavior was described by the biphasic model and it could be used to quantify Escherichia coli and S. aureus in chorizo. Keywords: starter, pathogens, fermented sausage chorizo type, modeling non- thermal inactivation.