Lactococcus lactis autóctono: evaluación del efecto antilisterial y de propiedades sensoriales en quesos tipo Cuartirolo

Abstract

Acid lactic bacteria (LAB) are part of milk natural microbiota and are components of many starter cultures used in cheese making. The LAB may exhibit antimicrobial activity, based on the production of various substances, among them, peptides called bacteriocins that can be produced in situ in cheese making. Some bacteriocins include in their spectrum of action Listeria monocytogenes, pathogen associated to food that represents a risk to public health. The aim of this study was to evaluate antilisterial effect of an autochthonous LAB in Cuartirolo cheese and determine if their use altered the sensory properties of that cheese. This experimental design included two treatments: with and without autochthonous Lactococcus lactis. Cheese was divided into two groups, the first one was inoculated with Listeria innocua, making the quantification two hours, seven days and fourteen days later. Regarding sensory evaluation a descriptive sensory technique was used. In this study, Lactococcus lactis GU96743 had an antagonic activity in vitro against Listeria innocua and Listeria monocytogenes. There were also significant differences (p<0,05) between the treatments in quantification of Listeria innocua in the samples of cheese evaluated. Except for the salty flavor, the sensorial properties did not show differences between treatments.