Browsing by Author "Viteri, Rafael"

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    Changes in the antibacterial capacity of Ulmo honey in relation to the contribution of Eucryphia cordifolia pollen
    (VUP FOOD RESEARCH INST, BRATISLAVA, 2021) Montenegro, Gloria; Velasquez, Patricia; Viteri, Rafael; Giordano, Ady
    Ulmo honey is known for its antibacterial characteristics. However, the importance of the content from Eucryphia cordifolia in the honey regarding its non-peroxidic antibacterial capacity is unknown. The present work evaluated the antibacterial activity of Ulmo honey with various percentages of pollen from E. cordifolia against various bacteria, determine the non-peroxidic capacity of Ulmo honey and, finally, compare that capacity with Manuka and Jarrah honeys. The antibacterial activity was evaluated by agar diffusion test and the non-peroxide capacity was evaluated by the reactivity with the catalase enzyme. The tests were carried out against Escherichia coli, Staphylococcus aureus and Streptococcus pyogenes. The results showed a relationship between the percentage of floral pollen from E. cordifolia and the antibacterial activity of Ulmo honey. It was also observed than the antibacterial activity of Ulmo honey can have values similar to Manuka and Jarrah honeys.
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    Eucryphia cordifolia extracts: Phytochemical screening, antibacterial and antioxidant activities
    (2021) Viteri, Rafael; Giordano, Ady; Montenegro, Gloria; Zacconi, Flavia C. M.
    Eucryphia cordifolia is a native and dominant species from the Temperate Forest in the southern region of Chile. It is a crucial melliferous species producing unifloral honey with outstanding antibacterial properties with great commercial value at international markets. A phytochemical screening was developed by colorimetric and gravimetric methods. Antioxidant activities were assessed by using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and ferric ion reducing antioxidant power (FRAP) method. The minimum bactericidal concentration (MBC) was the method used to determine the antibacterial activity. The results revealed the highest antioxidant activity for the methanolic extracts of branches (IC50 35.7 mu g/mL for DPPH, IC50 11.0 mu g/mL for ABTS, and 4.6 mM FeSO4 center dot 7H(2)O/g in FRAP), attributed to its high content of total phenols (332.8 mg GAE/g). The quantification of the MBC led to values in the range of 0.78-12.5 mg/mL for S. aureus and S. pyogenes, and 6.25-50 mg/mL for E. coli and P. aeruginosa, respectively. The presented work provides valuable first in vitro evidence regarding the potential application of E. cordifolia extracts as antioxidants and antibacterial agents in the nutraceutical and phytopharmaceutical industry.