Influence of the preservative material HOLDBACTM on the growth and proliferation of Listeria on the surfaces of cheeses

Abstract

Three varieties of cheese were selected for the experiment: Genuine Olomouc-brand soft ripened cheese, Loose-brand acid curd cheese, and Slovak-style string cheese. Their surfaces were inoculated with Listeria cells of a defined density and then treated with the preservative material HOLDBAC^TM at its optimal concentration. The cheeses were stored at two different temperatures for the periods of 2, 5, 9, and 14 days, after which the effectiveness of the treatment with the preservative material was determined. The results were compared with the effectiveness of the material on the growth and proliferation of Listeria when the application of the preservative material was made before the artificial contamination of the cheese surface with Listeria. The experiment demonstrated only a slightly greater effectiveness of HOLDBAC^TM when it was applied before the microbial contamination. Complete inhibition of Listeria was not observed when using this approach.