Encapsulation and release profiles of caffeine from microparticles

The purpose of this study was to encapsulate caffeine in alginate-chitosan cross-linked microparticles enriched with ascorbic acid by applying electrostatic extrusion technique. Three different forms of caffeine were encapsulated: liquid extract of caffeine from the plant guarana (Paullinia cupana), food-grade solid caffeine and analytical-grade caffeine. High performance liquid chromatography (HPLC-PDA) was used to evaluate the release kinetics of caffeine from microbeads in water, while the corresponding antioxidant capacity was evaluated by applying the ABTS radical scavenging assay. Scanning electron microscopy and laser diffraction particle size determination were used to provide information about the physical properties of microparticles. The microbeads encapsulating caffeine were uniformly sized spheres of about 600-800 μm. The encapsulation efficiency of all microparticles ranged between 70-80%. Caffeine was mainly released within 10-15 min, depending on the used caffeine form, while the ascorbic acid was relatively rapidly released from microbeads according to antioxidant capacity exhibited in water. The obtained results suggest that electrostatic extrusion can be applied for the entrapment of caffeine in alginate-chitosan microbeads, while the addition of ascorbic acid further enhances the antioxidant activity of such obtained microcapsules

Adsorption of T-2 toxin by natural mineral adsorbents

The contamination of animal feed with mycotoxins represents a worldwide problem leading to economic losses in animal production. According to the Food and Agriculture Organization (FAO), 25% of the world's cereal grain production is contaminated with mycotoxins. The most common mycotoxins found in grains are the aflatoxins, ochratoxins, fumonisins, trichothecenes, zearalenone and the ergopeptine alkaloids. Trichothecenes, constitute the largest group of Fusarium mycotoxins. Among others, T-2 toxin is the most acute toxic trichothecene. In this paper, adsorption of T-2 toxin by natural mineral adsorbents zeolite-clinop-tilolite and smectite minerals - bentonite and hectorite, at pH 3 was investigated. The highest adsorption index was achieved for hectorite (95%), while clinoptilolite and bentonite showed low adsorption index for T-2 toxin, 8% and 13%, respectively. Results of T-2 toxin adsorption on hectorite, at different amount of solid phase in suspension, and at pH 3, 7 and 9, showed that toxin adsorption indexes increased with increase of adsorbent concentration in suspension, at all investigated pH values. No significant differences in T-2 toxin adsorption by hectorite, at pH 3, 7 and 9 were observed

Microbiota depletion promotes browning of white adipose tissue and reduces obesity.

Brown adipose tissue (BAT) promotes a lean and healthy phenotype and improves insulin sensitivity. In response to cold or exercise, brown fat cells also emerge in the white adipose tissue (WAT; also known as beige cells), a process known as browning. Here we show that the development of functional beige fat in the inguinal subcutaneous adipose tissue (ingSAT) and perigonadal visceral adipose tissue (pgVAT) is promoted by the depletion of microbiota either by means of antibiotic treatment or in germ-free mice. This leads to improved glucose tolerance and insulin sensitivity and decreased white fat and adipocyte size in lean mice, obese leptin-deficient (ob/ob) mice and high-fat diet (HFD)-fed mice. Such metabolic improvements are mediated by eosinophil infiltration, enhanced type 2 cytokine signaling and M2 macrophage polarization in the subcutaneous white fat depots of microbiota-depleted animals. The metabolic phenotype and the browning of the subcutaneous fat are impaired by the suppression of type 2 cytokine signaling, and they are reversed by recolonization of the antibiotic-treated or germ-free mice with microbes. These results provide insight into the microbiota-fat signaling axis and beige-fat development in health and metabolic disease

A synthesis of radial growth patterns preceding tree mortality

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