932 research outputs found
Preservation of a highly perishable food, watermelon juice, at and above room temperature under mild pressure (hyperbaric storage) as an alternative to refrigeration
The feasibility of food preservation under pressure (hyperbaric storage) at and above room temperatures,
as an alternative to refrigeration was evaluated. Preservation of a highly perishable food, watermelon
juice, was studied at pressures of 25e150 MPa and temperatures ranging 20e37 C, being compared to
refrigeration and storage at atmospheric pressure at the same temperatures.
Hyperbaric storage at 75 MPa (20e37 C) revealed an inhibitory effect on microbial growth, with at
least an equal performance compared to refrigeration. An additional inactivation effect was verified for
storage at 100 and 150 MPa, with reduction of the initial microbial counts to 1.00 Log CFU/mL for
enterobacteriaceae and yeasts and moulds, and from 4.43 ± 0.04 to 3.31 ± 0.04 and 2.99 ± 0.07 Log CFU/
mL, respectively, for total aerobic mesophiles (25 C).
In general, pH, titratable acidity and total soluble solids did not show a clear variation trend with
pressure and no considerable differences among storage conditions were verified. Cloudiness decreased
for samples stored under pressure and browning degree was in general lower in samples stored under
pressure compared to refrigeration.
This work demonstrates the potentiality of hyperbaric storage as a new preservation methodology, at
variable (uncontrolled) room temperature without energetic costs during storage, as an alternative to
refrigeration
The Safe-Port project: an approach to port surveillance and protection
SAFE-PORT is a recently started project addressing the complex issue of determining the best configurations of resources for harbour and port surveillance and protection. More specifically, the main goal is to find, for any given scenario, an adequate set of configuration solutions — i.e., number and type of sensors and equipments, their locations and operating modes, the corresponding personnel and other support resources — that maximize protection over a specific area.
The project includes research and development of sensors models, novel algorithms for optimization and decision support, and a computer-based decision support system (DSS) to assist decision makers in that task. It includes also the development of a simulation environment for modelling relevant aspects of the scenario (including sensors used for surveillance, platforms, threats and the environment), capable to incorporate data from field-trials, used to test and validate solutions proposed by the DSS. Test cases will consider the use of intelligent agents to model the behaviour of threats and of NATO forces in a realistic way, following experts’ definitions and parameters
NEW SEISMIC SOURCE ZONE MODEL FOR PORTUGAL AND AZORES
The development of seismogenic source models is one of the first steps in seismic hazard assessment. In seismic hazard terminology, seismic source zones (SSZ) are polygons (or volumes) that delineate areas with homogeneous characteristics of seismicity. The importance of using knowledge on geology, seismicity and tectonics in the definition of source zones has been recognized for a long time [1]. However, the definition of SSZ tends to be subjective and controversial. Using SSZ based on broad geology, by spreading the seismicity clusters throughout the areal extent of a zone, provides a way to account for possible long-term non-stationary seismicity behavior [2,3]. This approach effectively increases seismicity rates in regions with no significant historical or instrumental seismicity, while decreasing seismicity rates in regions that display higher rates of seismicity. In contrast, the use of SSZ based on concentrations of seismicity or spatial smoothing results in stationary behavior [4]. In the FP7 Project SHARE (Seismic Hazard Harmonization in Europe), seismic hazard will be assessed with a logic tree approach that allows for three types of branches for seismicity models: a) smoothed seismicity, b) SSZ, c) SSZ and faults. In this context, a large-scale zonation model for use in the smoothed seismicity branch, and a new consensus SSZ model for Portugal and Azores have been developed. The new models were achieved with the participation of regional experts by combining and adapting existing models and incorporating new regional knowledge of the earthquake potential. The main criteria used for delineating the SSZ include distribution of seismicity, broad geological architecture, crustal characteristics (oceanic versus continental, tectonically active versus stable, etc.), historical catalogue completeness, and the characteristics of active or potentially-active faults. This model will be integrated into an Iberian model of SSZ to be used in the Project SHARE seismic hazard assessment
COMPILATION OF ACTIVE FAULT DATA IN PORTUGAL FOR USE IN SEISMIC HAZARD ANALYSIS
To estimate where future earthquakes are likely to occur, it is essential to combine information about past earthquakes with knowledge about the location and seismogenic properties of active faults. For this reason, robust probabilistic seismic hazard analysis (PSHA) integrates seismicity and active fault data. Existing seismic hazard assessments for Portugal rely exclusively on seismicity data and do not incorporate data on active faults. Project SHARE (Seismic Hazard Harmonization in Europe) is an EC-funded initiative (FP7) that aims to evaluate European seismic hazards using an integrated, standardized approach. In the context of SHARE, we are developing a fully-parameterized active fault database for Portugal that incorporates existing compilations, updated according to the most recent publications. The seismogenic source model derived for SHARE will be the first model for Portugal to include fault data and follow an internationally standardized approach. This model can be used to improve both seismic hazard and risk analyses and will be combined with the Spanish database for use in Iberian- and European-scale assessments
Isolation and characterization of an exopolysaccharide‐producing Leuconostoc citreum strain from artisanal cheese
peer-reviewedHigh molar mass exopolysaccharides (EPS) produced from sucrose by lactic acid bacteria (LAB) are of great interest as natural additives to use in foods, medical and pharmaceutical industry. This study aimed to identify the EPS produced by Leuconostoc citreum L3C1E7 isolated from Pico cheese and characterize the strain for technological and probiotic potential. Purified EPS was isolated from the culture of L. citreum L3C1E7 by ethanol precipitation, with a yield of 520 mg ml−1. The EPS-producing strain had a mucoid phenotype and average molecular weight of 5·88 × 106 Da. The structural characterization of the purified EPS was determined by 1H, 13C and two-dimensional NMR spectroscopy. EPS was composed of alternating α-(1→6)-linked and α-(1→3)-linked D-glucopyranyl units, suggesting the existence of an alternan. The strain was slow acidifying, produced diacetyl and displayed high esterase/lipase and aminopeptidase activities, which promote the desirable flavours in dairy products. Moreover, L. citreum showed moderate resistance to the adverse conditions of the gastrointestinal (GI) tract and high adhesion to GI cells. This work provides a better understanding of EPS produced by L. citreum and the potential application of EPS-producing strain in food and/or as a probiotic culture.Fuel Cycle Technologie
Heterosis and combining ability for ear yield in a diallel cross among six maize varieties
Este estudo teve o objetivo de estimar os efeitos das capacidades geral e específica de combinação, e os valores de heterose, na produção de espigas de cruzamentos dialélicos parciais entre seis variedades de milho (Zea mays L.) em melhoramento, no Centro Nacional de Pesquisa de Milho e Sorgo, (CNPMS), em Sete Lagoas, MG. Os tratamentos compreenderam as variedades CMS 05, CMS 04, CMS 22, CMS 11, CMS 12 e CMS 28, além dos seus quinze híbridos intervarietais (F1). A análise conjunta de variância para produção de espigas mostrou efeitos significativos (P <0.01) para as capacidades geral e específica de combinação e para as interações com locais. Tais resultados indicam variabilidade originada de efeitos gênicos aditivos e não-aditivos. As variedades CMS 04 e CMS 05 apresentaram, respectivamente, os maiores valores para efeitos de capacidade geral de combinação, 142,82 e 233,93, e média geral para peso de espigas de 4.528 kg/ha e 4.445 kg/ha, respectivamente. Os maiores efeitos para capacidade específica de combinação corresponderam aos cruzamentos CMS 05 x CMS 28 com 462,28 e CMS 11 x CMS 28 com 392,87. Os valores percentuais de heterose em relação a média dos pais foram de 21,16% e 17,49%e em relação ao pai mais produtivo foram de 12,92% e 13,28%, para os dois híbridos intervarietais citados. A média de produção das variedades paternais (4.127 kg/ha) foi inferior à média dos seus quinze híbridos (4.433 kg/ha). A maior produção média, 5.026 kg/ha, resultou do cruzamento entre as variedades CMS 05 e CMS 28.The objective of this study was to estimate the general and specific combining ability effects and heterosis value for ear yield from e diallel cross among six varieties of maize (Zea mays L.) under breeding at the Centro Nacional de Pesquisa de Milho e Sorgo (CNPMS) at Sete Lagoas, MG, Brazil. The treatments were: CMS 04, CMS 05, CMS 11, CMS 12, CMS 22, CMS 28 and their 15 possible F1 hybrids. The combined analysis showed general and specific effects to be highly significant (P < 0.01), as well as their interactions with locations. There is an indication of variability among varieties with the presence of additive and nonadditive gene effects. The varieties CMS 04 and CMS 05 presented the highest values for general combining ability effects, 142.82 and 233.93, and mean ear weights of 4.528 kg/ha and 4.445 kg/ha, respectively. The hybrids CMS 05 x CMS 28 and CMS 11 x CMS 28 presented the highest values for specific combining ability effects of 462.28 and 392.87, respectively. Heterosis percentual values related to parental mean were 21.16% and 17.49% and to the highest yialding parent were 12.92% and 13.28% for the hybrids CMS 05 x CMS 28 and CMS 11 x CMS 28, respectively. Mean yield of parentals (4.127 kg/ha) was lower tham mean yield of the 15 hybrids (4,433 kg/ha). The highest mean yield was 5.026 kg/ha for the hybrid CMS 05 x CMS 28
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