From olive leaves to spherical nanoparticles by one-step RESS process precipitation

In this work, spherical nanoparticles to be used in cosmetic, agro food or pharmaceutical industries have been directly precipitated from olives leaves in one-step RESS process. The leaves were brought into contact with supercritical CO2, and a fraction of the compounds from the flavone and flavonol families that can be found in the leaves were dissolved; then, by depressurizing the vessel, these compounds formed particles in the nanometer range. A complete factorial design was generated to thoroughly determine the influence from the main parameters on the RESS process with respect to the precipitated nanoparticles and their heterogeneity. Their antioxidant activity was also evaluated. Different pressures (250-350 bar), temperatures (60 and 100 degrees C), leaves sample weights (2 and 4 g) and cosolvent volumes, namely ethanol (9 and 18 mL), were studied as the main parameters that could affect the solvation and precipitation of the particle with active compounds in the leaves. Other parameters such as contact time (1 h) or nozzle size diameter (100 mu m) remained unchanged. The antioxidant activity was evaluated by means of the radical scavenging method using the radical 2,2-diphenyl-1-picrylhydrazole (DPPH). Spherical particles with diameters in the range of 55 nm to 4 mu m were obtained. Lower pressures and higher temperatures seemed to result in a reduction of the mean particle size. Greater volume of cosolvent is also recommended to reduce mean particle size. However, lower pressure, temperature and volume of cosolvent seems to promote a greater homogeneity of the particles. By means of chromatographic analyses, the main compounds, responsible for the antioxidant activity, such as oleuropein, quercetin or apigenin among others were identified

Análisis de los niveles de nutrientes críticos (azúcar, grasa y sal) declarados en alimentos procesados expendidos en Loja, Ecuador

La calidad nutricional de los alimentos processados es aún subestimada, a pesar de su incidência em la salud de la población. El objetivo de este trabajo fue brindar una perspectiva de la calidad de los alimentos procesados expendidos en la ciudad de Loja, Ecuador, em función del nivel de nutrientes críticos: azúcar, grasa, sal. Se valoraron 200 alimentos de 80 marcas de cereales para desayuno, granolas y galletas; carnes y preparaciones, yogures, pescados, bebidas no carbonatadas, jugos y néctares; disponibles en 10 supermercados. Los datos se obtuvieron directamente de las etiquetas, su valoración se realizó mediante la normativa de etiquetado vigente em Ecuador. Los resultados muestran el porcentaje de cada tipo de alimento y grupo incluídos em los niveles bajo, medio y alto de los nutrientes indicados. El 80% de cereales, 58,6% de bebidas y 47,1% de yogures fueron altos em azúcar. El mayor número de produtos registro um nível medio de grasa y lamayoría de carnes y preparaciones, fueron altos en sal. Se concluye que los alimentos procesados de mayor consumo en Loja, Ecuador, aportan elevados niveles de nutrientes críticos; existiendo pocas opciones de alimentos processados saludables, especialmente en bebidas, cárnicos y cereales

Una revisión sistemática de la literatura acerca de modelos, programas y estrategias de intervención sobre el acoso y el ciberacoso

El acoso y el ciberacoso representan problemas sociales comunes entre los niños y adolescentes de todo el mundo. Este problema se caracteriza por la intención de herir a alguien física o emocionalmente. El ciberacoso consiste en acosar a alguien a través de Internet. Se han propuesto múltiples programas, estrategias y modelos de intervención para combatir este problema. En este estudio se realizó una revisión bibliográfica sistemática sobre el estado de la investigación de los modelos, programas y estrategias de intervención para el bullying y el ciberbullying utilizando la metodología de Kitchenham. La investigación se basa en la identificación de 262 artículos de investigación en el campo del bullying y el ciberbullying en las bases de datos digitales Redalyc, Pubmed y SCOPUS, de los cuales se seleccionaron 83 trabajos para su análisis

Response Surface Methodology Optimization for Analytical Microwave-Assisted Extraction of Resveratrol from Functional Marmalade and Cookies

A novel analytical method based on microwave-assisted extraction has been successfully optimized and validated to determine resveratrol from functional marmalade and cookies. The optimization was performed using a Box–Behnken design with three factors: solvent composition (60−100% and 10−70% methanol in water for marmalade and cookies, respectively), microwave power (250−750 W), and solvent-to-solid ratio (20:5−60:5). The main and quadratic effects of solvent composition significantly contributed to the recovery values (p < 0.005) for both kinds of samples. Additionally, the solvent-to-solid ratio and the quadratic effect of microwave power also influenced the resveratrol recovery from functional marmalade. Hence, the optimum condition for resveratrol extraction from marmalade (80% methanol, 500 W, solvent-to-solid ratio 40:5) and cookies (80% methanol, 250 W, solvent-to-solid ratio 20:5) was proposed. The extraction kinetics (5−30 min) was then studied to clarify the complete recovery of resveratrol from the food matrices resulting in 15 min as the optimum extraction time. The developed method showed a satisfactory precision indicated by the coefficient of variation (CV) lower than 5.70% for both repeatability and intermediate precision. To check the matrix effects, the developed MAE procedures were applied to a number of commercial marmalade and cookies. The high-fat and fiber cookies resulted in overestimated values due to the interfering ingredients. As a final point, the methods successfully measured the stability of naturally present resveratrol in grape-derived products while preparing functional marmalade and cookies

Inclusion of Natural Antioxidants of Mango Leaves in Porous Ceramic Matrices by Supercritical CO2 Impregnation

Mango is one of the most important, medicinal tropical plants in the world from an economic point of view due to the presence of effective bioactive substances as co-products in its leaves. The aim of this work was to enhance the impregnation of natural antioxidants from mango leaves into a porous ceramic matrix. The effects of pressure, temperature, impregnation time, concentration of the extract and different porous silica on impregnation of phenolic compounds and antioxidant activity were analyzed. The volume of the pressurized fluid extract and amount of porous ceramic matrix remained constant. The best impregnation conditions were obtained at 6 h, 300 bar, 60 mg/mL, 35 &deg;C and with MSU-H porous silica. The results indicated that increasing the pressure, concentration of the extract and temperature during impregnation with phenolic compounds such as gallic acid and iriflophenone 3-C (2-O-p-hydroxybenzolyl)-&beta;-D-glucoside increased the antioxidant activity and the amount of total phenols

The antioxidant effect of Colombian berry (vaccinium meridionale Sw.) extracts to prevent lipid oxidation during pork patties shelf-life

A scarce amount of knowledge about the use of Colombian berry (CB) in meat products is available in the literature. This work studies the impact of the addition of CB extracts (CBE) on pork patties at three different concentrations in the range 250–750 mg/kg. CBE were characterized in terms of their polyphenolic profile and antioxidant activity [1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity, half maximal inhibitory antioxidant concentration (IC50), 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), ferric reducing antioxidant power assay (FRAP) and oxygen radical absorbance capacity (ORAC) tests)]. After pork patties elaboration, instrumental and sensorial colour, as well as lipid oxidation measured as thiobarbituric acid reactive substances assay (TBARS) values, were evaluated for 10 days of refrigerated storage in a modified atmosphere (80% O2–20% CO2). The total anthocyanin composition represented 35% of the polyphenolic substances of the CBE, highlighting high contents in cyanidin derivatives. Additionally, other flavonoids (quercetin and kaempferol compounds) and phenolics acids, substances positively related to antioxidant activity, were identified and quantified. In addition, the incorporation of CBE resulted in improvements in colour and lipid stability of pork patties, especially for the highest concentration used. Our findings demonstrated that CBE could be added to pork patties without impairing their sensorial profile. Overall, our results indicate that the use of CBE as a source of natural antioxidant, natural colourant, or even as a functional ingredient could be promising, but more studies are necessary to confirm it.CYTED | Ref. 119RT0568Axencia Galega de Innovación | Ref. IN607A2019 / 01PTA | Ref. PTA2017-14

Precipitation of particles using combined high turbulence extraction assisted by ultrasound and supercritical antisolvent fractionation

High Turbulence Extraction Assisted by Ultrasound combined with Supercritical Antisolvent Fractionation (SAF) was done to intensify the recovery of bixin and phenolic compounds from semi-defatted annatto seeds. Annatto seeds are extensively used due to its colorant properties and bioactive potential in human health. Modifications were performed in the SAF experimental apparatus in order to prevent losses of product. Results show that supercritical fractionation resulted in particle yields between 72.2–80.5%, 20–50% phenolics, and 66% bixin.3549CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP302423/2015-088882.305824/2013-012015/13299-