19,063 research outputs found

    Spray drying of grape juice from hybrid cv. Brs Violeta: microencapsulation of anthocyanins using Protein/maltodextrin blends as drying aids.

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    Grape juice contains high amounts of anthocyanins, with great potential for substituting synthetic food dyes. Carrier agents used in spray drying entraps anthocyanins, allowing their preservation. This work appraised whey protein/ maltodextrin (WM) and soy protein/maltodextrin (SM) blends as alternative carriers for spray drying of grape juice and encapsulation of anthocyanins. The effects of carrier agent concentration (CAC) and ratio protein/carrier agent (R) on grape juice powder properties were evaluated. The grape juice powders presented good solubility, low water content and high anthocyanin retention. WM blends resulted in higher yields and higher anthocyanin retention (from 77.9 to 94%) than SM blends, whereas SM blends leaded to higher encapsulation efficiency (>97%). Increasing CAC and R resulted in brighter powders, but reconstituted juices presented color parameters similar to those of fresh juice. WM and SM were suitable for encapsulating anthocyanins of grape juice, resulting in powders with potential applications in food industry. PRACTICAL APPLICATIONS The grape cultivar BRS violeta contains high levels of anthocyanins and is an alternative to produce antioxidant-rich and highly colored grape juice. Spray drying is applied for producing powdered grape juice with high anthocyanin content. In this technique, the addition of whey and soy proteins blended with maltodextrin as carrier agents avoid problems such as stickiness, which is negative to process yield and product quality. Moreover, the use of carrier agents in spray drying promotes the microencapsulation of bioactive compounds, allowing their protection and preservation during processing and storage. The grape juice powder from cv. BRS Violeta can be applied in the food industry as a potential substitute for synthetic food dyes, in addition to being a promising additive for incorporating anthocyanins into functional foods

    Orbital magnetism in axially deformed sodium clusters: From scissors mode to dia-para magnetic anisotropy

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    Low-energy orbital magnetic dipole excitations, known as scissors mode (SM), are studied in alkali metal clusters. Subsequent dynamic and static effects are explored. The treatment is based on a self-consistent microscopic approach using the jellium approximation for the ionic background and the Kohn-Sham mean field for the electrons. The microscopic origin of SM and its main features (structure of the mode in light and medium clusters, separation into low- and high-energy plasmons, coupling high-energy M1 scissors and E2 quadrupole plasmons, contributions of shape isomers, etc) are discussed. The scissors M1 strength acquires large values with increasing cluster size. The mode is responsible for the van Vleck paramagnetism of spin-saturated clusters. Quantum shell effects induce a fragile interplay between Langevin diamagnetism and van Vleck paramagnetism and lead to a remarkable dia-para anisotropy in magnetic susceptibility of particular light clusters. Finally, several routes for observing the SM experimentally are discussed.Comment: 21 pages, 7 figure

    Spectral and Fermi surface properties from Wannier interpolation

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    We present an efficient first-principles approach for calculating Fermi surface averages and spectral properties of solids, and use it to compute the low-field Hall coefficient of several cubic metals and the magnetic circular dichroism of iron. The first step is to perform a conventional first-principles calculation and store the low-lying Bloch functions evaluated on a uniform grid of k-points in the Brillouin zone. We then map those states onto a set of maximally-localized Wannier functions, and evaluate the matrix elements of the Hamiltonian and the other needed operators between the Wannier orbitals, thus setting up an ``exact tight-binding model.'' In this compact representation the k-space quantities are evaluated inexpensively using a generalized Slater-Koster interpolation. Because of the strong localization of the Wannier orbitals in real space, the smoothness and accuracy of the k-space interpolation increases rapidly with the number of grid points originally used to construct the Wannier functions. This allows k-space integrals to be performed with ab-initio accuracy at low cost. In the Wannier representation, band gradients, effective masses, and other k-derivatives needed for transport and optical coefficients can be evaluated analytically, producing numerically stable results even at band crossings and near weak avoided crossings.Comment: 12 pages, 7 figure

    7-Chloro-4-[(E)-2-(2-methoxy­benzyl­idene)hydrazin-1-yl]quinoline monohydrate

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    In the title hydrate, C17H14ClN3O·H2O, the dihedral angle between the quinoline fused-ring system and the benzene ring is 13.4 (2)° and the conformation about the C=N bond is E. In the crystal, Nh—H⋯Ow and Ow—H⋯Nq (h = hydro­zone, w = water and q = quinoline) hydrogen bonds generate a two-dimenstional network in the ac plane. A weak C—H⋯O inter­action helps to consolidate the packing

    Métodos de extração de hidrocarbonetos policíclicos aromáticos em amostra de solo, sedimento e lodo.

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    Potencial do armazenamento refrigerado para cenouras cultivads em sistema orgânico e convencional.

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    O objetivo do trabalho foi determinar algumas caracteristicas fisico-quimicas de cenouras cultivadas em sistema orgânico e convencional.Suplemento. Trabalho apresentado no 52. Congresso Brasileiro de Olericultura, Salvador, 2012
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