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.
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
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
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
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.
bitstream/item/12265/1/documentos_79.pd
Potencial do armazenamento refrigerado para cenouras cultivads em sistema orgânico e convencional.
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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