Aplicación de los diseños de Taguchi en el estudio de la inhibición del crecimiento de Listeria monocytogenes CECT 4032

Listeria monocytogenes is a gram positive bacterium, which can cause one of the most important food-borne diseases referred to as listeriosis. This species has a relevant importance for the food industry because it is widespread in nature and it survives and grows in a wide range of temperatures (0 to 44 °C), pH values (4.4 to 9.4), and high osmotic pressure conditions (NaCI concentrations higher than 10%). For these reasons, research on the behaviour of this species in the presence of food preservatives or the study of the influence of the culture conditions on the growth of Listeria may contribute to achieve the inhibition of its growth. In this study, a Taguchi's design is used to know the importance of several selected factors and their interactions. The factors and levels studied in this work are: Potassium sorbate (0.05, 0.125 and 0.3% (w/v)), Sodium polyphosphate (0,0.5 and 1 %(w/v)), Sodium chloride (0, 1.5 and 3% (w/v)), incubation temperature (4, 25 and 37 °C) and incubation length (1,2 and 6 days). In addition, interaction of Potassium sorbate with the rest of the factors is investigated to determine potential synergies between factors. The design demonstrates that the factors that have the strongest effect on growth of Listeria monocytogenes are incubation temperature followed by incubation length then Sodium polyphosphate concentration.