Avaliação da multiplicação de Listeria monocytogenes e da atividade antimicrobiana do Biomax D® em nata

Abstract

The proliferation of Listeria monocytogenes in cream, a milk derivative with high fat content, was evaluated as well as the anti-listerial activity of Biomax D® in this type of food. Antilisterial activity of Biomax was compared with nisin. Six treatments were used: T1: Cream + 10² CFU.g-1 of L. monocytogenes; T2: Cream + 10² CFU.g-1 L. monocytogenes + 2,5ppm nisin; T3: Cream + 10² CFU.g-1 L. monocytogenes + 1.5% Biomax; T4: Cream + 10(5) CFU.g-1 of L. monocytogenes; T5: Cream + 10(5) CFU.g-1 L. monocytogenes + 2,5ppm nisin; T6: Cream + 10(5) CFU.g-1 L. monocytogenes + 1.5% Biomax. L. monocytogenes counts were performed on three days storage at 8 °C (zero, 6, 14 and 20th day), with averages ranging between 2 and 10 log CFU.g-1 in treatments without the addition of nisin or Biomax®. However, there was elimination of the microorganism when the antimicrobials were added. It was found that L. monocytogenes is able to grow in cream, reaching high levels of contamination, even when it presents low initial counts. In this dairy derivative, Biomax D® presents antilisterial activity similar to nisin and might be used as a natural antibiotic for the control of L. monocytogenes in fatty foods.