RESUMO
Nanoemulsions are feasible delivery systems of lipophilic compounds, showing potential as edible coatings with enhanced functional properties. The aim of this work was to study the effect of emulsifier type (stearic acid (SA), Tween 80 (T80) or Tween 80/Span 60 (T80/S60)) and emulsification process (homogenization, ultrasound or microfluidization) on nanoemulsion formation based on oxidized corn starch, beeswax (BW) and natural antimicrobials (lauric arginate and natamycin). The response variables were physicochemical properties, rheological behavior, wettability and antimicrobial activity of BW-starch nanoemulsions (BW-SN). The BW-SN emulsified using T80 and microfluidized showed the lowest droplet size (77.6 ± 6.2 nm), a polydispersion index of 0.4 ± 0.0 and whiteness index (WI) of 31.8 ± 0.8. This BW-SN exhibited a more negative ζ-potential: -36 ± 4 mV, and Newtonian flow behavior, indicating great stability. BW-SN antimicrobial activity was not affected by microfluidization nor the presence of T80, showing inhibition of the deteriorative fungi R. stolonifer, C. gloeosporioides and B. cinerea, and the pathogenic bacterium S. Saintpaul. In addition, regardless of emulsifier type and emulsification process, BW-SN applied on the tomato surface exhibited low contact angles (38.5° to 48.6°), resulting in efficient wettability (-7.0 mN/m to -8.9 mN/m). These nanoemulsions may be useful to produce edible coatings to preserve fresh-produce quality and safety.
Assuntos
Anti-Infecciosos/uso terapêutico , Sistemas de Liberação de Medicamentos , Nanocompostos/química , Ceras/química , Anti-Infecciosos/química , Emulsões/química , Emulsões/uso terapêutico , Hexoses/química , Hexoses/uso terapêutico , Humanos , Nanocompostos/uso terapêutico , Polissorbatos/química , Polissorbatos/uso terapêutico , Amido/química , Amido/uso terapêutico , Ácidos Esteáricos/química , Ácidos Esteáricos/uso terapêuticoRESUMO
By the beginning of this century, yaws was a well-known endemic disease in Colombia. Colombian authorities estimated that by early 1930 there were 70,000 active cases of yaws, most of which were located in the Pacific coastal regions. With the advent of penicillin therapy, Colombia organized an anti-yaws campaign, which began in 1950. The campaign relied on the use of penicillin and house-to-house case finding. From 1950 to 1953 more than 111,000 persons with active cases of yaws and 125,000 of their contacts were treated with penicillin. The reported incidence of yaws declined dramatically, and by 1973 only 573 cases were reported in the endemic areas. By 1983 this number had fallen to 31. Because of the persistence of small foci of yaws activity, the anti-yaws campaign has been reorganized to provide a firm basis for the final eradication of the disease in Colombia.