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 cheese-making 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.

Films made with mucilage obtained from defatted chia seeds and incorporated with oregano (Origanum vulgare) and savory (Satureja montana) essential oils (0.1,1.0 and 1.5% v/v) were prepared to evaluate their physical, optical, mechanical and antifungal properties as well as their microstructure. The use of different types of essential oils (oregano or savory) only had a significant effect on the light transmittance, total color difference (∆E) and antifungal activity of the films. However, the kind of essential oil was not significant for the physical, optical and mechanical properties of the films. Increasing concentrations of essential oils up to 1.5% v/v led to a decrease in tensile strength (TS) and elongation at break (EB). Antifungal properties significantly increased with the incorporation of essential oils (p < 0.05). The antifungal activity of the chia mucilage films incorporated with O. vulgare and S. montana essential oil was screened by agar disc-diffusion assay against five mold strains commonly found in foods. Films containing 0.1% v/v of essential oils were not active, whereas films containing 1.0 and 1.5% v/v were very effective at inhibiting the growth of the tested mold strains (38.01–77.66%). Scanning electron microscopy showed that incorporation of essential oils caused some heterogeneity in the films and the surface displayed no pores or cracks as well as a better integration of oregano EO in the polymeric network. The results pointed out that the incorporation of oregano and savory essential oils as a natural antimicrobial agent has appreciable potential for the development of films as active packaging to control mold contamination and increase food safety.