RESUMO
In this study, the influence of the incorporation of eucalyptus (EO), tea tree (TT) and rosemary (RO) essential oils and Chiriyuyo extract (CE) on the structure and properties of thermoplastic starch (TPS) obtained from potato starch, glycerin and water was evaluated. All oils and the extract were used at a concentration of 0.5 g/100 g of TPS, while for TT, the effect of the concentration was also studied. The mixtures obtained were processed by extrusion and thermocompression molding. The sheets were characterized by XRD, FTIR, TGA, SEM and analyses of their mechanical properties, antimicrobial characteristics and biodegradability. The results show that the use of small concentrations of the oils in 70TPS does not induce changes in the TPS structure according to the results of XRD, FTIR and TGA, with each essential oil and CE affecting the mechanical properties unevenly, although in all cases, antimicrobial activity was obtained, and the biodegradability of TPS in soil was not modified. An increase in the concentration of TT in 60TPS causes marked changes in the crystallinity of TPS, providing a greater modulus with a higher concentration of TT. Regardless of the amount of TT, all sheets maintain antimicrobial characteristics, and their biodegradation in soil is delayed with a higher oil content.
RESUMO
OBJETIVO: El propósito del trabajo fue determinar la calidad microbiológica del agua termal del Balneario "El Tingo", situado a 2500 msnm, Provincia de Pichincha, Ecuador. Materiales y MÉTODOS: Se realizaron cuatro muestreos en diferentes épocas del año y en dos zonas del Balneario. Se determinaron "in situ" los parámetros fisicoquímicos (conductividad, dureza, oxígeno disuelto, pH y temperatura). La cuantificación de bacterias heterótrofas, coliformes y hongos se hizo en medios de cultivos específicos para cada grupo microbiano. La identificación de las cepas bacterianas aisladas se realizó de acuerdo con lo indicado por MacFaddin (2004). RESULTADOS: Los resultados indican que el agua termal del Tingo se clasifica como de conductividad muy fuerte, mineralización excesiva, aguas muy duras, con muy poco oxígeno disuelto, pH neutro e hipertermales. El contaje promedio de bacterias heterótrofas en el agua contenida en la cisterna del balneario fue de 2,10 X 102 UFC/mL, coliformes totales de 0,30 X 10 UFC/mL y hongos 1,00 X 10 UFC/mL. Para las duchas de agua termal los valores promedios fueron de 2,42 X 102 UFC/mL de bacterias heterótrofas, 0,85 X 10 UFC/mL coliformes totales y 0,68 X 10 UFC/mL de hongos. No se detectó la presencia de Escherichia coli en ninguna de las muestras analizadas. Se identificaron 14 cepas Gram negativas de los géneros Aeromonas, Burkholderia, Citrobacter y Pseudomonas, 5 Gram positivas de los géneros Bacillus y Staphylococcus y 2 cepas fúngicas del género Aspergillus. CONCLUSIONES: Los resultados obtenidos demuestran una población microbiana escasa y poco diversa, lo que implica una buena calidad del agua y de los acuíferos
OBJECTIVE: The purpose of research was determining the microbiological quality of the thermal water of the "El Tingo" Spa, located at 2500 mamsl, Pichincha Province, Ecuador. METHODS: Four samplings were carried out at different times of the year and in two areas of the Spa. The physicochemical parameters (conductivity, hardness, dissolved oxygen, pH, dissolved solids and temperature) were determined "in situ". The heterotrophic bacteria, coliforms and molds was determined, as well as the identification of the isolated strains according to the indicated by MacFaddin (2004). RESULTS: The Tingo thermal water is classified as very strong conductivity, excessive mineralization, very hard water, with very little dissolved oxygen, neutral pH and hyperthermal. The average count of heterotrophic bacteria in the water contained in the cistern of the spa were 2.10 X 102 CFU / mL, coliforms 0.30 X 10 CFU / mL and fungi1,00 X 10 CFU / mL. For the thermal water showers, the average values were 2.42 X 102 CFU/ mL of heterotrophic bacteria, 0.85 X 10 CFU / mL coliforms and 0.68 X 10 CFU/ mLfungi. Escherichia coli were not detectedin any of the samples. It was possible to identify 14 Gram negative strains of the genus Aeromonas, Burkholderia, Citrobacter and Pseudomonas, 5 Gram positive of the genera Bacillus and Staphylococcus and 2 fungal strains of the genus Aspergillus
