86 research outputs found
Lipid Process Markers of Durum Wheat Debranning Fractions
At present, whole grains are usually obtained by adding bran and middlings to refined flours, and this recombination leads to certain variations in the ratio of endosperm, bran and germ, resulting in flours with very different compositional characteristics and rheological properties. Therefore, this study focuses on the identification of specific lipid markers in different debranning fractions of Italian and Canadian durum wheat blends. The by-products obtained from five different debranning levels (3, 6, 9, 12 and 15%) had a high content of monounsaturated fatty acids and a higher concentration of tocopherols and sterols than the corresponding debranned grains. The Italian and Canadian durum wheat samples did not show significant differences in the content of these bioactive lipid compounds. In particular, palmitic acid, oleic acid, tocopherol isomers and total sterols could be useful biomarkers for evaluating the grain-to-tissue ratio in recombined flours
Microencapsulation of Phenolic Extracts from Cocoa Shells to Enrich Chocolate Bars
Cocoa bean shells were subjected to green extraction technologies, based on the absence of toxic organic solvents, to recover polyphenols; the extract was then encapsulated using a spray dryer and maltodextrin as coating agent. The best conditions observed in the spray drying tests (core-to-coating ratio 1:5; inlet temperature 150 °C; flow rate 6 ml min-1) were applied to produce the microcapsules used to enrich the same cocoa mass as the shells and processed for the preparation of the chocolate bars. Sensory analysis showed no significant differences between enriched chocolate bar and the unenriched reference one, except for the appearance. Both samples were then subjected to accelerated storage tests, at the end of which the polyphenols in the control chocolate bar (0.85 g 100 g-1) were reduced by about 50% (0.42 g 100 g-1), while in the enriched chocolate (1.17 g 100 g-1) by only 22% (0.97 g 100 g-1). The proposed process significantly enriched the chocolate bars with phenolic antioxidants recovered from cocoa waste without increasing the sensations of bitterness and astringency
Non-universal equilibrium crystal shape results from sticky steps
The anisotropic surface free energy, Andreev surface free energy, and
equilibrium crystal shape (ECS) z=z(x,y) are calculated numerically using a
transfer matrix approach with the density matrix renormalization group (DMRG)
method. The adopted surface model is a restricted solid-on-solid (RSOS) model
with "sticky" steps, i.e., steps with a point-contact type attraction between
them (p-RSOS model). By analyzing the results, we obtain a first-order shape
transition on the ECS profile around the (111) facet; and on the curved surface
near the (001) facet edge, we obtain shape exponents having values different
from those of the universal Gruber-Mullins-Pokrovsky-Talapov (GMPT) class. In
order to elucidate the origin of the non-universal shape exponents, we
calculate the slope dependence of the mean step height of "step droplets"
(bound states of steps) using the Monte Carlo method, where p=(dz/dx,
dz/dy)$, and represents the thermal averag |p| dependence of , we
derive a |p|-expanded expression for the non-universal surface free energy
f_{eff}(p), which contains quadratic terms with respect to |p|. The first-order
shape transition and the non-universal shape exponents obtained by the DMRG
calculations are reproduced thermodynamically from the non-universal surface
free energy f_{eff}(p).Comment: 31 pages, 21 figure
Berry phases for 3D Hartree type equations with a quadratic potential and a uniform magnetic field
A countable set of asymptotic space -- localized solutions is constructed by
the complex germ method in the adiabatic approximation for 3D Hartree type
equations with a quadratic potential. The asymptotic parameter is 1/T, where
is the adiabatic evolution time.
A generalization of the Berry phase of the linear Schr\"odinger equation is
formulated for the Hartree type equation. For the solutions constructed, the
Berry phases are found in explicit form.Comment: 15 pages, no figure
Protective action of lemongrass essential oil on mucilage from chia (Salvia hispanica) seeds
Mucilage extracted from chia seeds (Salvia hispanica) is reckoning an increasing interest for its mechanical and nutritional properties. Freeze-dried mucilage dispersed in solvent undergoes degradation, through autoxidation phenomena, that results in the loss of the initial rheological characteristics. In order to limit the extent of depolymerization, an essential oil (lemongrass essential oil, LEO) is here emulsified with chia mucilage (CM) suspensions, and the rheological behavior of samples containing LEO or not compared. Flow curves of CM suspensions and of CM emulsions dispersing LEO (O/W-CM) demonstrated that both the systems can be classified as plastic fluids, and that during storage a general decrease of the viscosity of CM suspensions is detected, while the viscosity of the O/W-CM systems remaining constant. The differences between the two systems were also confirmed by oscillatory tests and through measurements of intrinsic viscosity. By means of an accelerated oxidative test, it was unveiled that the short-term stability of CM suspensions is attributable to the reaction of oxidation, and that the presence of LEO, due to its anti-oxidative properties, allowed for preventing degradation phenomena on the chia mucilage. We conclude that the colloidal stability of chia-based mixtures can definitely be improved following to LEO treatment - hence forming an emulsion - thereby preventing short-term polymer degradation
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