570 research outputs found
Effect of Cold Plasma on Meat Cholesterol and Lipid Oxidation
Cold atmospheric plasma (CAP) is a novel non-thermal technology with potential applications in inactivating microorganisms in food products. However, its impact on food quality is not yet fully understood. The aim of this research is to study the impact of in-package plasma technology on the stability of cholesterol and total lipid in four different types of meat (beef, pork, lamb and chicken breast). Additionally, any changes in the primary or secondary lipid oxidation, which is undesirable from a health perspective, is investigated. CAP was not found to have any impact on the cholesterol or lipid content. However, higher peroxide and thiobarbituric acid reactive substances (TBARS) values were found for the treated samples, indicating that plasma can induce the acceleration of primary and secondary lipid oxidation. Finally, color was not affected by the treatment supporting the suitability of the technology for meat products
Influence of high-pressure processing on quality attributes of haddock and mackerel minces during frozen storage, and fishcakes prepared thereof
peer-reviewedThe study focused on assessing quality parameters of haddock and mackerel minces subjected to a high-pressure treatment (HP) at 200 and 300 MPa and frozen storage at −40 °C. Dry matter, water-holding capacity, protein solubility and oxidation, lipid oxidation, microbiological parameters, low molecular weight metabolites (LMW) and color parameters, were analyzed. The texture of fishcakes prepared on the basis of these fish minces was also studied, showing a decrease in firmness along with an increase in pressure. A marked inhibition of microbial growth was observed in fish minces when increasing the pressure level of HP-treatment. However, no significant effect (p < 0.05) on the content of primary and secondary lipid oxidation products was observed between untreated and 300 MPa-pressurized fish samples. The results suggested that HP-treatment could be successfully applied to both lean and fatty fish samples for reduction of microbial growth with minor changes in product quality.
Industrial relevance.
The application of high pressure (HP) treatment of 200 and 300 MPa could be successfully applied to both lean and fatty fish species before freezing for reduction of microbial growth. The degree of lipid oxidation is decreasing with an increase in pressure as a result of inactivation of prooxidative endogenous enzymes. Fish minces become slightly lighter and softer after HP-treatment conducted at 200 MPa due to denaturation of proteins, thus enhancing sensory properties of fishcakes prepared thereof
Interactive effects of elevated CO2, warming, and drought on photosynthesis of Deschampsia flexuosa in a temperate heath ecosystem
Global change factors affect plant carbon uptake in concert. In order to investigate the response directions and potential interactive effects, and to understand the underlying mechanisms, multifactor experiments are needed. The focus of this study was on the photosynthetic response to elevated CO2 [CO2; free air CO2 enrichment (FACE)], drought (D; water-excluding curtains), and night-time warming (T; infrared-reflective curtains) in a temperate heath. A/Ci curves were measured, allowing analysis of light-saturated net photosynthesis (Pn), light- and CO2-saturated net photosynthesis (Pmax), stomatal conductance (gs), the maximal rate of Rubisco carboxylation (Vcmax), and the maximal rate of ribulose bisphosphate (RuBP) regeneration (Jmax) along with leaf δ13C, and carbon and nitrogen concentration on a monthly basis in the grass Deschampsia flexuosa. Seasonal drought reduced Pn via gs, but severe (experimental) drought decreased Pn via a reduction in photosynthetic capacity (Pmax, Jmax, and Vcmax). The effects were completely reversed by rewetting and stimulated Pn via photosynthetic capacity stimulation. Warming increased early and late season Pn via higher Pmax and Jmax. Elevated CO2 did not decrease gs, but stimulated Pn via increased Ci. The T×CO2 synergistically increased plant carbon uptake via photosynthetic capacity up-regulation in early season and by better access to water after rewetting. The effects of the combination of drought and elevated CO2 depended on soil water availability, with additive effects when the soil water content was low and D×CO2 synergistic stimulation of Pn after rewetting. The photosynthetic responses appeared to be highly influenced by growth pattern. The grass has opportunistic water consumption, and a biphasic growth pattern allowing for leaf dieback at low soil water availability followed by rapid re-growth of active leaves when rewetted and possibly a large resource allocation capability mediated by the rhizome. This growth characteristic allowed for the photosynthetic capacity up-regulations that mediated the T×CO2 and D×CO2 synergistic effects on photosynthesis. These are clearly advantageous characteristics when exposed to climate changes. In conclusion, after 1 year of experimentation, the limitations by low soil water availability and stimulation in early and late season by warming clearly structure and interact with the photosynthetic response to elevated CO2 in this grassland species
Molecular structural order and anomalies in liquid silica
The present investigation examines the relationship between structural order,
diffusivity anomalies, and density anomalies in liquid silica by means of
molecular dynamics simulations. We use previously defined orientational and
translational order parameters to quantify local structural order in atomic
configurations. Extensive simulations are performed at different state points
to measure structural order, diffusivity, and thermodynamic properties. It is
found that silica shares many trends recently reported for water [J. R.
Errington and P. G. Debenedetti, Nature 409, 318 (2001)]. At intermediate
densities, the distribution of local orientational order is bimodal. At fixed
temperature, order parameter extrema occur upon compression: a maximum in
orientational order followed by a minimum in translational order. Unlike water,
however, silica's translational order parameter minimum is broad, and there is
no range of thermodynamic conditions where both parameters are strictly
coupled. Furthermore, the temperature-density regime where both structural
order parameters decrease upon isothermal compression (the structurally
anomalous regime) does not encompass the region of diffusivity anomalies, as
was the case for water.Comment: 30 pages, 8 figure
Recommended from our members
The influence of soil communities on the temperature sensitivity of soil respiration
Soil respiration represents a major carbon flux between terrestrial ecosystems and the atmosphere, and is expected to accelerate under climate warming. Despite its importance in climate change forecasts, however, our understanding of the effects of temperature on soil respiration (RS) is incomplete. Using a metabolic ecology approach we link soil biota metabolism, community composition and heterotrophic activity, to predict RS rates across five biomes. We find that accounting for the ecological mechanisms underpinning decomposition processes predicts climatological RS variations observed in an independent dataset (n = 312). The importance of community composition is evident because without it RS is substantially underestimated. With increasing temperature, we predict a latitudinal increase in RS temperature sensitivity, with Q10 values ranging between 2.33 ±0.01 in tropical forests to 2.72 ±0.03 in tundra. This global trend has been widely observed, but has not previously been linked to soil communities
ACTiCLOUD: Enabling the Next Generation of Cloud Applications
Despite their proliferation as a dominant computing paradigm, cloud computing systems lack effective mechanisms to manage their vast amounts of resources efficiently. Resources are stranded and fragmented, ultimately limiting cloud systems' applicability to large classes of critical applications that pose non-moderate resource demands. Eliminating current technological barriers of actual fluidity and scalability of cloud resources is essential to strengthen cloud computing's role as a critical cornerstone for the digital economy. ACTiCLOUD proposes a novel cloud architecture that breaks the existing scale-up and share-nothing barriers and enables the holistic management of physical resources both at the local cloud site and at distributed levels. Specifically, it makes advancements in the cloud resource management stacks by extending state-of-the-art hypervisor technology beyond the physical server boundary and localized cloud management system to provide a holistic resource management within a rack, within a site, and across distributed cloud sites. On top of this, ACTiCLOUD will adapt and optimize system libraries and runtimes (e.g., JVM) as well as ACTiCLOUD-native applications, which are extremely demanding, and critical classes of applications that currently face severe difficulties in matching their resource requirements to state-of-the-art cloud offerings
Effect of Cold Plasma on Meat Cholesterol and Lipid Oxidation
peer reviewedCold atmospheric plasma (CAP) is a novel non-thermal technology with potential applications in inactivating microorganisms in food products. However, its impact on food quality is not yet fully understood. The aim of this research is to study the impact of in-package plasma technology on the stability of cholesterol and total lipid in four different types of meat (beef, pork, lamb and chicken breast). Additionally, any changes in the primary or secondary lipid oxidation, which is undesirable from a health perspective, is investigated. CAP was not found to have any impact on the cholesterol or lipid content. However, higher peroxide and thiobarbituric acid reactive substances (TBARS) values were found for the treated samples, indicating that plasma can induce the acceleration of primary and secondary lipid oxidation. Finally, color was not affected by the treatment supporting the suitability of the technology for meat products
Static and Dynamic Properties of a Viscous Silica Melt Molecular Dynamics Computer Simulations
We present the results of a large scale molecular dynamics computer
simulation in which we investigated the static and dynamic properties of a
silica melt in the temperature range in which the viscosity of the system
changes from O(10^-2) Poise to O(10^2) Poise. We show that even at temperatures
as high as 4000 K the structure of this system is very similar to the random
tetrahedral network found in silica at lower temperatures. The temperature
dependence of the concentration of the defects in this network shows an
Arrhenius law. From the partial structure factors we calculate the neutron
scattering function and find that it agrees very well with experimental neutron
scattering data. At low temperatures the temperature dependence of the
diffusion constants shows an Arrhenius law with activation energies which
are in very good agreement with the experimental values. With increasing
temperature we find that this dependence shows a cross-over to one which can be
described well by a power-law, D\propto (T-T_c)^gamma. The critical temperature
T_c is 3330 K and the exponent gamma is close to 2.1. Since we find a similar
cross-over in the viscosity we have evidence that the relaxation dynamics of
the system changes from a flow-like motion of the particles, as described by
the ideal version of mode-coupling theory, to a hopping like motion. We show
that such a change of the transport mechanism is also observed in the product
of the diffusion constant and the life time of a Si-O bond, or the space and
time dependence of the van Hove correlation functions.Comment: 30 pages of Latex, 14 figure
- …