Quantification, migration and decline of natamycin in blue cheeses

Abstract

This study aimed to quantify the concentration of natamycin in the rind and verify its migration in Gorgonzola type cheese, as well as evaluating the decline of natamycin in Blue cheese during maturation. Eight samples of Gorgonzola cheese were purchased in supermarkets of which six were produced in different regions of Brazil, one in Argentina and one in Italy. The rinds of four of the eight cheese samples presented natamycin concentrations above 5 mg/kg, three of these samples being from Brazil and one from Argentina. With the exception of the Italian cheese, all the samples showed natamycin inside the cheese mass (up to 6 mm from the rind). To evaluate the rate of decline during the ripening of Blue cheeses, samples were collected from an industry as from day 0 (day of manufacture) up to the 45 days of ripening. The results showed that, after 45 days of ripening for cheese immersed in a 3% natamycin solution, the concentration in the rind was 4 times the amount allowed by the legislation (5 mg/kg). However, for immersion in a 1.5% natamycin solution, after 25 days of ripening, the antifungal concentration was in accordance with the standards established by the legislation.