Characteristics of ripened Tronchón cheese from raw goat milk containing legally admissible amounts of antibiotics

Abstract

The aim of this study was to evaluate the transfer of the most widely used antibiotics in dairy goats from milk to cheese as well as their effect on the cheesemaking process and cheese characteristics during ripening. Antibiotic-free milk was spiked individually with 7 veterinary drugs (amoxicillin, benzylpenicillin, cloxacillin, erythromycin, ciprofloxacin, enrofloxacin, and oxytetracycline) at an equivalent concentration of the European Union maximum residue limit. Spiked goat milk was used to make mature Tronchón cheeses, which were analyzed at 0, 30, and 60 d of maturation to determine pH, chemical composition, proteolytic and lipolytic activities, and color and textural properties. A sensory evaluation of 60-d ripened cheeses was carried out. Cheeses from raw antibiotic-free goat milk were made simultaneously to be used as reference. The cheese-making process was unaffected by the presence of most antibiotics evaluated. Only erythromycin and oxytetracycline significantly increased the time required for cheese production (122 ± 29 and 108 ± 25 min, respectively). However, variable amounts of antibiotics, ranging from 7.4 to 68%, were transferred from milk to cheese, with oxytetracycline and quinolones showing the highest retention rates. In general, antibiotic residues present in the cheeses at the beginning of maturation decrease significantly along time. Thus, β-lactams and erythromycin residues were not detectable after 30 d of ripening. However, relatively high concentrations of enrofloxacin (148 ± 12 µg/kg) and ciprofloxacin (253 ± 24 µg/kg) residues were found in the cheeses after 60 d of maturation. The quality characteristics of the Tronchón cheeses were only slightly affected by such substances, with few significant differences in the free fatty acid concentration and color and textural properties of the cheeses. Results herein indicate that the use of goat milk containing antibiotics, such as quinolones, at the European Union maximum residue limit for cheese production could adversely affect the safety of the final products because relatively high concentrations of these substances could be retained in soft and semi-mature cheeses, making it necessary to assess the risk for consumer health. Studies on the partition of the antibiotic substances during cheese-making, using specific technologies, would be convenient to guarantee the safety of cheese and related products.

Recent advances in dairy goat products

“…A different approach using whey as an indicator was used by Giraldo et al [47]. Results were similar to those of Quintanilla et al [46], where different antibiotics varying in retention behaviour in curd.…”

“…The presence of antibiotic residues in cheese has been evaluated recently [46]. Goat milk was added with European Union maximum residue limits of amoxicillin, benzylpenicillin, cloxacillin, erythromycin, ciprofloxacin, enrofloxacin, and oxytetracycline to manufacture ripened Spanish Tronchon cheese.…”

“…The presence of antibiotic residues in milk did not markedly impact the manufacturing process of dairy goat products, including yogurt [50] and cheese [46], but different results could be observed in relation to the antibiotic type.…”

Short communication: Volatile profile of matured Tronchón cheese affected by oxytetracycline in raw goat milk

“…On the other hand, in less industrialized countries where no routinely control of antibiotics in goat milk are implemented, the risk of antibiotic residues in the milk supply increases. Studies available on the effect of such substances in milk on the cheese-making and the organoleptic characteristics of the ripened cheese are very scarce (Cabizza et al, 2017;Quintanilla et al, 2019). Therefore, the objective of this work was to evaluate the impact of different concentrations of oxytetracycline in raw goat's milk on the volatile profile of Tronchón cheese during ripening.…”

“…The chemical composition of the milk used for cheeses production were analyzed using MilkoScan FT6000 (Foss, Hillerød, Denmark), the mean values (mean ± standard deviation) being: 14.71 ± 0.37% total solids, 5.37 ± 0.19% fat, 3.98 ± 0.22% protein and 4.63 ± 0.07% lactose. Traditional semi-hard Tronchón goat cheese was made from raw milk following the cheese-making procedure reported by Quintanilla et al (2019). Ten cheeses were obtained from each vat, which were sampled in duplicate at 0, 15, 30, 45 and 60 days of ripening for further analysis.…”