BLUE PIGMENTATION IN CHEESES?

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Bacteria belonging to the genus Pseudomonas are contaminants often associated with the deterioration of dairy products. In milk, this deterioration is generally attributed to the production of lipolytic and proteolytic enzymes. These enzymes are also associated with the deterioration of cheese, however, another type of deterioration in this product that has also been related to contamination by strains of Pseudomonas is the appearance of a blue pigmentation. In 2010, many cases of blue pigmentation in Mozzarella cheese, produced in Europe and the United States, were reported and official analyzes linked this phenomenon to contamination of the cheese by strains of Pseudomonas fluorescens, coming from the water used in processing. The frequently reported episodes were a serious problem for dairy producers and, since then, several studies have been started to investigate and detect the agents that cause blue pigmentation in cheese.

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The appearance of this pigment is a phenomenon usually registered in fresh, high humidity cheeses, and it occurs even when the product is strictly kept under strict refrigeration. Dairy products in Brazil have increasingly reported the occurrence of this deterioration, but due to the lack of scientific information about it, many people mistakenly end up associating it with chemical residues in the final products. The doctoral research by Rafaela da Silva Rodrigues, a member of the INOVALEITE team, aims to study this type of deterioration. Her research project is entitled “Investigation and characterization of the production of blue pigment by Pseudomonas spp.” and the team has already managed to identify different species of Pseudomonas that cause this pigment .