On 27 May last year, a lady from Turin delivered a mozzarella with the Italian brand produced in Germany to the Nas that had turned blue. Eleven months after April 8 in Turin the same scene is repeated. This time it is Italian mozzarella bought in a local market in the city. The story no longer attracts the attention of the newspapers, because in the last year dozens of episodes of colored mozzarella have been reported in different regions.
The problem of the colored cut-offs is not new for the experts, who recall some scientific papers published in 2003 on this problem. Research at the time indicated that the bacteria of the species Pseudomonas fluorescens and Pseudomonas aeruginosa present in the drinking water used in the production chain were the cause of the anomalous color.
” In recent months we have analyzed a hundred samples taken by the health authorities and a dozen mozzarella brought directly by the citizens – explains Lucia Decastelli of the experimental zooprophylactic institute of Piedmont, Liguria and Valle D’Aosta – finding in some cases the presence of Pseudomonas, in others of molds and yeasts combined with both pink and blue colors ». The hypotheses advanced by the experts on the causes are three: water contaminated by fluorescent bacteria, the use of curds obtained from powdered milk for farms to which the tracer has been eliminated to prevent food use, the contamination of curds by Pseudomonas frozen German.
The issue is further complicated because the Pseudomonas bacteria responsible for the coloring are present in both blue and white mozzarella. The finding was also found in the laboratory where some mozzarella was deliberately contaminated but did not assume an anomalous color.
The considerations on which everyone agrees is that the color forms more easily in mozzarella consumed in part, and left in the refrigerator. The temperature of the refrigerator also plays an important role. If the thermometer shows 8 ° C the color is formed after a week if instead the cheese remains at room temperature + 20 ° C 48 hours are enough.
Another element to consider is that colored mozzarella must be withdrawn from the market, because it is an altered food, but it is not pathogenic. The Pseudomonas in fact gives a bad appearance but does not cause a stomach ache.
The mystery of coloring has not been solved, which is why many companies have decided as a precaution to reduce the deadline from 25 days to two weeks. The blue mozzarella is therefore lurking. If opening the refrigerator you get the unpleasant surprise, don’t be alarmed, because the sight is unpleasant but the danger of getting sick from having eaten it the day before is quite ridiculous.