Development of a microencapsulated probiotic delivery system with whey, xanthan, and pectin.

Pediococcus pentosaceus is a lactic acid bacterium that has probiotic potential proven by studies. However, its viability can be affected by adverse conditions such as storage, heat stress, and even gastrointestinal passage. Thus, the aim of the present study was to microencapsulate and characterize microcapsules obtained by spray drying and produced only with whey powder (W) or whey powder combined with pectin (WP) or xanthan (WX) in the protection of P. pentosaceus P107. In the storage test at temperatures of - 20 °C and 4 °C, the most viable microcapsule was WP (whey powder and pectin), although WX (whey powder and xanthan) presented better stability at 25 °C. In addition, WX did not show stability to ensure probiotic potential (< 6 Log CFU mL-1) for 110 days and the microcapsule W (whey powder) maintained probiotic viability at the three temperatures (- 20 °C, 4 °C, and 25 °C) for 180 days. In the exposition to simulated gastrointestinal juice, the WX microcapsule showed the best results in all tested conditions, presenting high cellular viability. For the thermal resistance test, WP microcapsule was shown to be efficient in the protection of P. pentosaceus P107 cells. The Fourier transform infrared spectroscopy (FTIR) results showed that there was no chemical interaction between microcapsules of whey powder combined with xanthan or pectin. The three microcapsules produced were able to protect the cell viability of the microorganism, as well as the drying parameters were adequate for the microcapsules produced in this study.

Tolerance to benzalkonium chloride and antimicrobial activity of Butia odorata Barb. Rodr. extract in Salmonella spp. isolates from food and food environments.

Salmonellosis, caused by the consumption of contaminated foods, is a major health problem worldwide. The aims of this study were to assess the susceptibility of Salmonella spp. isolates to benzalkonium chloride (BC) disinfectant and the antimicrobial activity of Butia odorata Barb. Rodr. extract against the same isolates from food and food environments. Moreover, phenotypic and genotypic resistance profiles, the presence of virulence genes and biofilm forming ability were determined. The minimum inhibitory concentration (MIC) of B. odorata extract against Salmonella spp. ranged from 10 to >19 mg.mL-1. Resistance to ampicillin, streptomycin, nalidixic acid, sulfonamide, trimethoprim/sulfamethoxazole, trimethoprim, tetracycline, and chloramphenicol was observed. In addition, multidrug resistance was observed in seven isolates (26.92%). The MIC of BC ranged from 32 to 64 mg.L-1, higher concentrations in comparison with wild-type MICs, and therefore were considered tolerant. Several resistance genes were detected, of which the most common were aadA, qacEΔ1, blaTEM, int1, sul1, and tetA. All isolates carried at least one virulence gene and produced biofilms on stainless steel surfaces at 10 and 22 °C. On the other hand, the B. odorata extract showed activity against Salmonella spp., and it has the potential to be used as a natural antimicrobial to control this important foodborne pathogen, despite its virulence potential and antimicrobial resistance profile.

Essential oil of the leaves of Eugenia uniflora L.: antioxidant and antimicrobial properties.

Essential oil (EO) of the leaves of Eugenia uniflora L. (Brazilian cherry tree) was evaluated for its antioxidant, antibacterial and antifungal properties. The acute toxicity of the EO administered by oral route was also evaluated in mice. The EO exhibited antioxidant activity in the DPPH, ABTS and FRAP assays and reduced lipid peroxidation in the kidney of mice. The EO also showed antimicrobial activity against two important pathogenic bacteria, Staphylococcus aureus and Listeria monocytogenes, and against two fungi of the Candida species, C. lipolytica and C. guilliermondii. Acute administration of the EO by the oral route did not cause lethality or toxicological effects in mice. These findings suggest that the EO of the leaves of E. uniflora may have the potential for use in the pharmaceutical industry.