Antimicrobial activity in cheese whey as an indicator of antibiotic drug transfer from goat milk

Abstract

[EN] Raw goat milk spiked with antibiotics was coagulated with rennet, the whey separated and the transfer of 18 antibiotics from the milk to the whey was evaluated by estimating antimicrobial activity of the whey using microbial inhibitor tests. Antibiotic-free whey (negative whey) spiked with different antibiotics was used as a reference. The antimicrobial activity in whey from milk spiked with most b-lactam drugs was lower (0e40%) than that of the reference whey, suggesting that these antibiotics are mostly released from curd and transferred to the whey. However, for most non-b-lactam drugs, an 84e100% reduction in the relative antimicrobial activity in whey was obtained, indicating the higher susceptibility for retention in curd. The traceability of antibiotics through the cheese-making process will make it possible to determine whether control systems are required to prevent the negative implications of the presence of antibiotic drug residues in cheese and whey products.