Cow's milk is currently the most consumed product worldwide. However, due to various direct and indirect contamination sources, different chemical and microbiological contaminants have been found in cow's milk. This review details the main contaminants found in cow's milk, referring to the sources of contamination and their impact on human health. A comparative approach highlights the poor efficacy and effects of the pasteurization process with other methods used in the treatment of cow's milk. Despite pasteurization and related techniques being the most widely applied to date, they have not demonstrated efficacy in eliminating contaminants. New technologies have appeared as alternative treatments to pasteurization. However, in addition to causing physicochemical changes in the raw material, their efficacy is not total in eliminating chemical contaminants, suggesting the need for new research to find a solution that contributes to improving food safety.

The production and consumption of oranges generates a large amount of lignocellulosic waste that is deposited in landfills without receiving any type of treatment that allows it to be used as by-products. The objective of the present investigation was to obtain bioalcohol through the saccharification and fermentation of lignocellulosic residues of the peel of the orange (Citrus sinensis). Three (3) different levels of sulfuric acid were used as treatment, to alter the lignocellulosic structure of the biomass, subsequently, a hydrolysis with cellulase enzymes was carried out, analyzing the presence of reducing sugars by spectrophotometry. The fermentation was carried out with two (2) different concentration levels of Sacharomyces cerevisiae yeast, subsequently, it was distilled and the presence of volatile organic compounds was determined by gas chromatography. The reducing sugars present in the highest proportion were: glucose (26.6 ± 0.77 g.L-1) and fructose (21.26 ± 0.51 g. L-1); the volatile organic compound with the highest concentration was ethanol (76.96%) and the index with the highest bioalcohol yield was obtained with the treatment with the highest concentration of sulfuric acid and yeast (12.72 ± 0.65 g. L-1); Orange peels are by-products of vegetable origin that can be used for the production of bioalcohol with percentages of ethanol higher than 76%.

Background: Given the chemical richness of medicinal plants (Bidens pilosa L. and Croton floccosus) in Ecuador, they are considered the natural source of numerous medicines. Methods: The leaves were dried at 40°C and 50°C and the extracts were characterized by means of phytochemical screening, verifying the presence of secondary metabolites such as alkaloids, reducing sugars, phenols, flavonoids, tannins and saponins. Three extraction processes were carried out, with two solvents of different polarities: hexane and ethanol. The extraction methods that were applied to the leaves of the plants were Soxhlet, ultrasonic bath and maceration, the latter two at room temperature and Soxhlet at the boiling temperature of the solvent. Determination of the total content of phenols and flavonoids is carried out using the Follin-Ciocalteau colorimetric reaction, Quercetin standard, Aluminum Chloride solution measured with a UV-Vis spectrophotometer. The antioxidant activity was performed with the DPPH radical and measured with the same equipment. Results: The highest content of total phenols obtained by employing the Soxhlet method for extraction when the material was dried at 50°C was 48.609 ± 0.370 mg GAE/g of dry sample for Bidens pilosa L. while in the case of Croton floccosus it was 128.212 ± 0.601 mg GAE/g of dry sample obtained from the extraction by means of maceration. Finally, the antioxidant activity against the 1.1-diphenyl-2-picryl-hydrazyl radical was determined, and it was found that the Bidens pilosa L. species performed better and responded better to the test, with an IC50 value of 239.33 µg/mL, than Croton floccosus (IC50 of 644.125 µg/mL). Conclusions: The following preliminary phytochemical study of the Bidens pilosa L. and Croton floccosus plants provided important information on the content of secondary metabolites and response to the DPPH radical reported for the first time in Ecuador, which may be future use for medicinal application.

Certain chemicals/materials that are contaminants of emerging concern (CECs) have been widely detected in water bodies and terrestrial systems worldwide while other CECs occur at undetectable concentrations. The primary sources...

La harina integral de Cucurbita moschata posee un alto contenido de carotenoides totales que pueden contribuir a la pigmentación del tarso y la piel de pollos de engorde. El objetivo de la investigación fue evaluar el efecto de la sustitución de maíz en tres niveles por harina integral de zapallo (10 %, 12 % y 15 %) sobre el rendimiento productivo y la pigmentación de los pollos. Se utilizó un diseño experimental completamente al azar con cuatro tratamientos y cuatro repeticiones, cada una con 15 pollos de la línea Cobb 500 sin sexar. Se evaluaron las variables productivas de peso, ganancia de peso, consumo de alimento, consumo acumulado, conversión y pigmentación de piel y tarsos de los pollos con el uso del colorímetro Konica-Minolta CR-300. Los análisis de varianza de las variables consumo, consumo acumulado, ganancia de peso y peso acumulado presentaron diferencias estadísticas (p < 0,05) en las etapas primera y segunda entre los diferentes tratamientos. En la etapa de finalización, luego de 42 días, no se observaron diferencias significativas entre las variables estudiadas y se alcanzó un peso de 2 232,22 g a 2 384,00 g por pollo. Los resultados sobre la pigmentación de piel y tarsos muestran que la inclusión del 15 % de harina integral de zapallo generó diferencias significativas entre el tratamiento T0 y el tratamiento T2. Se concluye que la utilización de harina integral de zapallo en sus diferentes formulaciones logró resultados satisfactorios; sin embargo, el 15 % de esta harina resultó favorable sobre los rendimientos productivos y la pigmentación de los pollos.

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