Quinolones in goats' milk: Effect on the cheese-making process, chemical and microbial characteristics of acid-coagulated cheeses

Abstract

[EN] The effect of the presence in goats' milk of enrofloxacin and ciprofloxacin on cheese-making and the characteristics of acid-coagulated cheeses was evaluated. Raw goats' milk was spiked with quinolones at maximum residue limit concentration (100 ¿g kg¿1). For each antibiotic, three batches of cheese were made by acid coagulation (pH 4.6) using a commercial starter culture. Cheese-making process, gross composition and microbial counts in the cheeses were unaffected by the presence of quinolones in milk. However, relatively high amounts of these substances were retained in the cheeses, with residual concentrations of 146.5 ± 4.9 ¿g kg¿1 and 150.7 ± 25.7 ¿g kg¿1 for enrofloxacin and ciprofloxacin, respectively, after 20 days of maturation. Results suggest that the use of goats' milk containing legally admissible amounts of enrofloxacin and/or ciprofloxacin would have no impact on cheese manufacturing, composition and microflora of acid-coagulated cheese. However, the transfer of these substances to the final products could compromise consumer safety.