Essential oil blends (EOBs) have been increasingly studied for their multifunctional benefits in animal nutrition and food science. This study evaluates the impact of an EOB composed of eucalyptus and peppermint oil on the physicochemical, microbiological, and sensory characteristics of dairy products—milk, cream, and colonial cheese. Forty lactating cows were assigned to two groups: control and EOB addition (3.6 mL/cow/day) on the diet. Sensory analysis showed that the addition of EOB does not significantly alter milk or cream characteristics but enhances cheese texture perception. Fatty acid analysis revealed a higher proportion of SFA and lower UFA in cheese produced from the EOB group. Additionally, the EOB reduced lipid oxidation throughout the ripening process, with significantly lower TBARS values at 45 days of maturation (0.1300), compared to those from cows without supplementation of EOB (0.1585), suggesting improved oxidative stability. Microbiome analysis indicated that the bacterial community composition remained stable, with a slight reduction in Streptococcus spp. in EOB cheeses. No drastic shifts in microbial diversity were detected, and a lower overall abundance of bacterial taxa was observed in the EOB group. Results suggest that EOBs in dairy cow diets may positively modulate dairy product characteristics and alter the microbiota without compromising sensory quality. This study highlights the technological potential of EOB supplementation in dairy production.

Colonial cheese is a dairy product widely produced in southern Brazil using traditional methods, predominantly using raw milk in production, and is being marketed informally. Therefore, this study aimed to evaluate the physicochemical, in addition to the presence of Staphylococcus aureus, staphylococcal enterotoxins, and the antimicrobial susceptibility profiles of Colonial cheeses marketed at fairs in the municipality of Chapecó, state of Santa Catarina. Ten cheese samples were evaluated, analyzing the physicochemical properties (moisture, protein, and ash). Microbiological analyses followed ISO 6888-1:2021 for coagulase-positive staphylococci counts, species identification, enterotoxin detection, and antimicrobial susceptibility, using VIDAS® and VITEK® 2 equipment based on AOAC 2007.06-2007. All cheeses were within acceptable moisture, protein, and ash content. However, coagulase-positive staphylococci counts ranged from <1.0×10² to 1.0×10⁴ CFU/g, with one sample exceeding the legal limit and deemed unfit for consumption. Staphylococcus aureus was identified in 74% of the isolates, although no staphylococcal enterotoxins were detected. Multidrug-resistant coagulase-positive staphylococci had high resistance rates to erythromycin (36.84%) and to kanamycin, ampicillin, and benzylpenicillin (26.32%). These findings highlight significant microbiological risks and reinforce the urgent need for strengthened hygienic practices during milk handling and cheese production, continuous antimicrobial resistance monitoring, and targeted training programs for artisanal producers to ensure food safety and protect public health.

Colonial cheese production represents a valuable cultural and economic activity in southern Brazil. This study evaluated the effect of oral supplementation of dairy cows with an essential oil blend (EOB)—a combination of eucalyptus oil, peppermint oil, and menthol crystals—on the chemical composition and quality parameters of Colonial cheese during 21 days of ripening. Nine dairy cows were randomly assigned to three groups: control, EOB3.6 (3.6 g/cow/day), and EOB7.2 (7.2 g/cow/day). Milk from each treatment was used to produce Colonial cheeses, which were analyzed for physicochemical composition, texture, color, lipid profile, thiobarbituric acid reactive substances (TBARS), and microbiological quality at different ripening stages. Data were analyzed by analysis of variance (ANOVA) using SAS^® software, following verification of normality and homogeneity of variances. When assumptions were met, repeated-measures ANOVA was applied, and means were compared using Tukey’s test (p < 0.05). Sensory data were evaluated by ANOVA using XLSTAT^® (Addinsoft, Paris, France). EOB supplementation maintained the physicochemical integrity of the cheeses, with a gradual increase in fat content during maturation (40 g/100 g at 21 days, p < 0.05). At seven days, the EOB7.2 treatment showed lower lipid oxidation (TBARS = 0.063, p < 0.05), indicating antioxidant potential. Significant interactions between treatment and maturation were observed for color parameters and polyunsaturated fatty acids (PUFA) (p < 0.05). Cheeses from EOB7.2 presented higher saturated fatty acids (SFA) and lower unsaturated fatty acids (UFA) compared with the control (p < 0.05). No Salmonella spp. or Staphylococcal enterotoxins were detected. Counts of coagulase-positive Staphylococcus, molds, and yeasts remained stable, while Escherichia coli counts were lower in EOB-supplemented cheeses throughout ripening. Overall, EOB supplementation improved oxidative stability and microbiological safety without compromising the technological or compositional quality of Colonial cheese.