Efeito da adi����o de CO2 sobre o crescimento microbiano em macarr��o tipo massa fresca

O presente trabalho foi desenvolvido com o objetivo de avaliar o efeito da adi����o de CO2 sobre a qualidade do macarr��o tipo massa fresca. O uso de atmosfera modificada no interior da embalagem, com concentra����es mais elevadas de CO2, tem sido empregado comercialmente com a finalidade de inibir microrganismos, principalmente os aer��bios. Dessa forma, neste trabalho foi empregada uma nova t��cnica para a adi����o do CO2 no produto. Esta t��cnica consistiu em carbonatar a ��gua que foi utilizada para a produ����o do macarr��o tipo massa fresca, em substitui����o �� inje����o do g��s CO2 na embalagem. Foram testadas as concentra����es de 160 e 745mg/L de CO2. Os resultados mostraram, pelas an��lises microbiol��gicas, que o n��vel de 745mg/L de CO2 foi satisfat��rio para a inibi����o de bolores e leveduras durante os 50 dias de armazenamento a 7±1ºC. No entanto, n��o houve efeito na inibi����o de psicrotr��ficos e coliformes totais.

Redu����o do teor de limoneno e bergapteno do ��leo essencial de bergamota adsorvido em s��lica gel pelo CO2 - supercr��tico

Testou-se a utiliza����o do CO2 supercr��tico na extra����o seletiva de compostos oxigenados (linalol e acetato de linalila) contidos no ��leo essencial de bergamota (Citrus bergamia Risso), var. bergamia, adsorvido em s��lica gel contendo baixo teor de limoneno e bergapteno. A densidade do di��xido de carbono e a temperatura de extra����o foram otimizadas, e os extratos obtidos foram analisados por cromatografia. Nas condi����es estudadas, observou-se uma redu����o de 72% no teor de limoneno e 92,5% para o bergapteno, sendo extra��dos 52% de linalol e 69,4% de acetato de linalila.

Avalia����o de diferentes h��bridos su��nos submetidos �� insensibiliza����o el��trica e gasosa (CO2): parte 2 - mensura����es objetivas de qualidade

Su��nos provenientes de tr��s linhagens gen��tica (A, B e C) comercializados no Brasil, com peso vivo de 100 a 120 kg foram submetidos ao insensibilizador el��trico manual (Karl Schermer 220-230/250 volts, 45-60 Hz e 1,4-1,5A) e ao gasoso coletivo (Combi-Butina 90% CO2) no mesmo abatedouro. O sistema gasoso proporcionou aos h��bridos valores (b*) superiores (p<0,001) quando comparados ao sistema el��trico, assim como diferen��as nos valores m��dios de reflet��ncia luminosa interna (Hennessy-gp4) aos 45 min. pm e 24�� h pm (p<0,05). Quando submetidos ao sistema gasoso, diferen��as entre os h��bridos nos valores m��dios de luminosidade superficial (L) 24�� h pm (p<0,0001), pH 24�� h pm (SM) (p<0,0001), valores (b*) 24�� h pm (p<0,05), reflect��ncia luminosa interna aos 45 min e 24�� h (LD) (p<0,001) foram observadas. Utilizando-se o sistema manual el��trico verificaram-se diferen��as significativas nos valores m��dios de reflet��ncia luminosa interna (LD) aos 45 min. e 24�� h pm (p<0,001), assim como nos valores m��dios de pH 24�� h pm (SM) e (SC) (p<0,05). Entretanto as diferen��as obtidas entre os sistemas de insensibiliza����o e h��bridos estudados n��o foram suficientes para proporcionar diferen��as significativas nos valores de capacidade de reten����o de ��gua, perda por exsuda����o e "umidade exprim��vel".

Avalia����o de diferentes h��bridos su��nos submetidos �� insensibiliza����o el��trica e gasosa (CO2). Parte 3: mensura����es visuais de qualidade

Tr��s linhagens gen��tica su��na A, B e C comercializadas no Brasil, foram submetidas ao insensibilizador el��trico manual (Karl Schermer 220-230/250 volts, 45-60 Hz e 1,4 - 1,5 A) e ao sistema gasoso coletivo (COMBI-BUTINA 90% CO2) . A insensibiliza����o el��trica proporcionou n��veis mais elevados de salpicamento nas regi��es do cox��o mole (0,477 e 0,26, p < 0,01), paleta/cranial (0,154 e 0,039, p < 0,05), paleta/central (0,261 e 0,052, p < 0,001), paleta/caudal (0,180 e 0,030, p < 0,01), lombo/central (0,185 e 0,065, p < 0,01), lombo/caudal (0,06 e 0,207, p < 0,01) e lombo/lateral externa (0,061 e 0,013, p < 0,05), assim como salpicamento mais difuso nas regi��es do cox��o-mole (0,461 e 0,279, p < 0,05), paleta/cranial (0,154 e 0,039, p < 0,01), paleta/central (0,231 e 0,039, p < 0,001) e paleta/caudal (0,185 e 0,026, p < 0,001). O sistema el��trico tamb��m proporcionou maiores ��ndices de escoria����es da pele nas regi��es da paleta (1,098 e 0,795, p < 0,001), corpo (1,04 e 0,948, p < 0,05) e pernil (0,84 e 0,68, p < 0,001), assim como elevados ��ndices de reflexo palpebral (11,57%) comparativamente ao gasoso (2,86%), de um total de 426 su��nos. Pequenos ��ndices de fraturas ��sseas e contus��es musculares em animais de ambos os sistemas foram observados.

Avalia����o de diferentes h��bridos su��nos submetidos �� insensibiliza����o el��trica e gasosa (CO2). Parte 1: mensura����o de indicadores sangu��neos de estresse

Su��nos provenientes de tr��s linhagens gen��ticas A, B e C comercializadas no Brasil, com peso vivo de 100 a 120 kg foram submetidos ao insensibilizador el��trico manual (Karl Schermer 220-230/250 volts, 45-60 Hz e 1,4 -1,5 A) e ao sistema gasoso coletivo (COMBI-BUTINA 90% CO2). Al��quotas sangu��neas, para determina����o dos n��veis de creatina fosfoquinase (CPK), lactato e cortisol, assim como amostras do m��sculo semimembranosus (10 g) para a determina����o do gene halotano, foram coletadas. Comparando-se os sistemas de insensibiliza����o el��trico e gasoso (CO2), o el��trico demonstrou ser mais estressante, proporcionando maiores concentra����es plasm��ticas de cortisol (p < 0,001) e lactato (p < 0,001) para as linhagens gen��ticas A e C, nas condi����es estudadas, por��m n��o se observou diferen��as significativas para os indicadores sangu��neos e sistemas de insensibiliza����o em quest��o quando a linhagem B foi considerada. Diferen��as significativas entre as linhagens gen��ticas A, B e C foram obtidas comparando-se os valores plasm��ticos de creatina fosfoquinase (p < 0,001), lactato (p < 0,001) e cortisol (p < 0,001) quando atordoados com o sistema gasoso, entretanto, quando o sistema el��trico foi utilizado, somente os valores de cortisol apresentaram diferen��as significativas (p < 0,001). A presen��a do gene halotano (Nn) foi observada somente na linhagem B.

Pre-treatment of thermoduric spores in CO2 modified atmosphere and their survivability during food extrusion

The aim of this experiment was to evaluate how susceptible spores become to mechanical damage during food extrusion after being submitted to CO2. B. stearothermophilus spores sowed to corn and soy mix were submitted to 99% CO2 for 10 days and extruded in a single-screw extruder. The treatments were: T1 - spore-containing samples, extruded at screw rotational speed of 65 rpm and barrel wall temperature of 80 ��C; T2 - as T1, except for screw rotational speed of 150 rpm; and T3 - as T2, except that samples were submitted to the modified atmosphere. The results for cell viability, minimum and maximum residence times, and static pressure were T1 - 19.90 �� 3.24%, 123.3 �� 14.50 seconds; 203.3 �� 14.05 seconds; 2.217 �� 62 kPa; T2 - 21.42 �� 8.24%, 70.00 �� 5.77 seconds; 170.00 �� 4.67 seconds; 2.310 �� 107 kPa; and T3 - 11.06 �� 2.46%, 86.00 �� 7.23 seconds; 186.00 �� 7.50 seconds; 2.403 �� 93 kPa, respectively. It was concluded that the extrusion process did reduce the cell count. However, screw rotational speed variation or CO2 pre-treatment did not affect cell viability.

Immunomodulatory effects of supercritical fluid CO2 extracts from freeze-dried powder of Tenebrio molitor larvae (yellow mealworm)

Abstract In order to take full advantage of Tenebrio molitor larvae (yellow mealworm) resources, the supercritical CO2 fluid freeze-dried powder of T. molitor larvae (fdTML) extraction on the immune systems of mice was carried out. The results about the effects of supercritical CO2 fluid fdTML extraction on carbon expurgation and phagocytosis of peritoneal macrophages experiments of mice indicated that the fdTML extraction enhanced observably carbon expurgatory index, phagocytic rate and phagocytic index. The fdTML extraction could stimulate response of delayed hypersensitivity. The proliferation of ConA-induced mitogenic reponse for spleen lymphocyte was also increased. The amount of hemolytic antibody in mice serum increased compared with those of the control group mice. The half of hemolysis values in serum of treated mice increased compared to the control group. Furthermore, serum NO content in all treatment groups was higher than that of the control group whereas acid phosphatase and alkaline phosphatase activity was only significantly higher relative to the control group. Our findings suggest that supercritical CO2 fluid the fdTML extraction has potential as a health food supplement.

Inactivation of Staphylococcus aureus in raw salmon with supercritical CO2 using experimental design

Abstract Considering the microbial safety of consumption of raw foods (Asian food), this study aimed to explore the inactivation S. aureus in raw salmon by supercritical CO2 treatment (SC-CO2). For this purpose, experimental design methodology was employed as a tool to evaluate the effects of pressure (120-220 bar), the depressurization rate (10 to 100 bar.min&#8211;1) and the salmon:CO2 mass relation (1:0.2 to 1:1.0). It was observed that the pressure and the depressurization rate was statistically significant, i.e. the higher the system pressure and depressurization rate, the greater the microbial inactivation. The salmon: CO2 mass relation did not influence the S. aureus inactivation in raw salmon. There was a total reduction in S. aureus with 225 bar, a depressurizing rate of 100 bar.min&#8211;1, a salmon: CO2 mass relation of 1:0.6, for 2 hours at 33 ��C.

Climate change and global responsibility - the role of energy consumption, GDP and CO2 emissions

Climate change is one of the biggest challenges faced by this generation. Despite being the single most important environmental challenge facing the planet and despite over two decades of international climate negotiations, global greenhouse gas (GHG) emissions continue to rise. By the middle of this century, GHGs must be reduced by as much as 40-70% if dangerous climate change is to be avoided. In the Kyoto Protocol no quantitative emission limitation and reduction commitments were placed on the developing countries. For the planning of the future commitments period and possible participation of developing countries, information of the functioning of the energy systems, CO2 emissions development in different sectors, energy use and technological development in developing countries is essential. In addition to the per capita emissions, the efficiency of the energy system in relation to GHG emissions is crucial for the decision of future long-term burden sharing between countries. Country���s future development of CO2 emissions can be defined by the estimated CO2 intensity of the future and the estimated GDP growth. The changes in CO2 intensity depend on several factors, but generally developed countries��� intensity has been increasing in the industrialization phase and decreasing when their economy shifts more towards the system dominated by the service sector. The level of the CO2 intensity depends by a large extent on the production structure and the energy sources that are used. Currently one of the most urgent issues regarding global climate change is to decide the future of the Kyoto Protocol. Negotiations on this topic have already been initiated, with the aim of being finalised by the 2015. This thesis provides insights into the various approaches that can be used to characterise the concept of comparable efforts for developing countries in a future international climate agreement. The thesis examines the post-Kyoto burden sharing questions for developing countries using the contraction and convergence model, which is one approach that has been proposed to allocate commitments regarding future GHG emissions mitigation. This new approach is a practical tool for the evaluation of the Kyoto climate policy process and global climate change negotiations from the perspective of the developing countries.

Production of magnesium carbonates from serpentinites for CO2 mineral sequestration : optimisation towards industrial application

Global warming is one of the most alarming problems of this century. Initial scepticism concerning its validity is currently dwarfed by the intensification of extreme weather events whilst the gradual arising level of anthropogenic CO2 is pointed out as its main driver. Most of the greenhouse gas (GHG) emissions come from large point sources (heat and power production and industrial processes) and the continued use of fossil fuels requires quick and effective measures to meet the world���s energy demand whilst (at least) stabilizing CO2 atmospheric levels. The framework known as Carbon Capture and Storage (CCS) ��� or Carbon Capture Utilization and Storage (CCUS) ��� comprises a portfolio of technologies applicable to large���scale GHG sources for preventing CO2 from entering the atmosphere. Amongst them, CO2 capture and mineralisation (CCM) presents the highest potential for CO2 sequestration as the predicted carbon storage capacity (as mineral carbonates) far exceeds the estimated levels of the worldwide identified fossil fuel reserves. The work presented in this thesis aims at taking a step forward to the deployment of an energy/cost effective process for simultaneous capture and storage of CO2 in the form of thermodynamically stable and environmentally friendly solid carbonates. R&D work on the process considered here began in 2007 at ��bo Akademi University in Finland. It involves the processing of magnesium silicate minerals with recyclable ammonium salts for extraction of magnesium at ambient pressure and 400���440���C, followed by aqueous precipitation of magnesium in the form of hydroxide, Mg(OH)2, and finally Mg(OH)2 carbonation in a pressurised fluidized bed reactor at ~510���C and ~20 bar PCO2 to produce high purity MgCO3. Rock material taken from the Hitura nickel mine, Finland, and serpentinite collected from Bragan��a, Portugal, were tested for magnesium extraction with both ammonium sulphate and bisulphate (AS and ABS) for determination of optimal operation parameters, primarily: reaction time, reactor type and presence of moisture. Typical efficiencies range from 50 to 80% of magnesium extraction at 350���450���C. In general ABS performs better than AS showing comparable efficiencies at lower temperature and reaction times. The best experimental results so far obtained include 80% magnesium extraction with ABS at 450���C in a laboratory scale rotary kiln and 70% Mg(OH)2 carbonation in the PFB at 500���C, 20 bar CO2 pressure for 15 minutes. The extraction reaction with ammonium salts is not at all selective towards magnesium. Other elements like iron, nickel, chromium, copper, etc., are also co���extracted. Their separation, recovery and valorisation are addressed as well and found to be of great importance. The assessment of the exergetic performance of the process was carried out using Aspen Plus�� software and pinch analysis technology. The choice of fluxing agent and its recovery method have a decisive sway in the performance of the process: AS is recovered by crystallisation and in general the whole process requires more exergy (2.48���5.09 GJ/tCO2sequestered) than ABS (2.48���4.47 GJ/tCO2sequestered) when ABS is recovered by thermal decomposition. However, the corrosive nature of molten ABS and operational problems inherent to thermal regeneration of ABS prohibit this route. Regeneration of ABS through addition of H2SO4 to AS (followed by crystallisation) results in an overall negative exergy balance (mainly at the expense of low grade heat) but will flood the system with sulphates. Although the ��A route is still energy intensive, its performance is comparable to conventional CO2 capture methods using alkanolamine solvents. An energy���neutral process is dependent on the availability and quality of nearby waste heat and economic viability might be achieved with: magnesium extraction and carbonation levels ��� 90%, the processing of CO2���containing flue gases (eliminating the expensive capture step) and production of marketable products.

Characterization of amine-based CO2 adsorbent for Direct Air Capture

Direct air capture technologies extract CO2 from air at a concentration of as low as 400ppm. The captured CO2 can be used for the production of synthetic methane or liquid fuels. In the literature survey of this thesis, results related to direct air capture by using solid sorbents are presented and critically discussed. In the experimental part, a proprietary amine functionalized resin is characterized for direct air capture. Structural comparison is also made to a commercial resin of similar type. Based on the literature survey, the most important parameters in direct air capture process are low adsorption and desorption temperatures, good cyclic stability in dry and humid conditions, high CO2 outlet purity and a high working capacity. Primary amine functionalized solid sorbents are found to often have good qualities for direct air capture, but overall process performance is rarely studied exhaustively. Based on FTIR spectra, both resin adsorbents are found to be consisted of polystyrene functionalized with primary amine, and capture CO2 by forming carbamate. The commercial resin is more porous, has a slightly higher particle size and contains fewer impurities. Important physical parameters are gained of the proprietary resin, such as internal porosity and median particle size. The resin���s amine group is found to endure thermal treatment reasonably well. CO2 adsorption capacity gained by thermal gravimetry from 400ppm CO2 is highest at 25oC, and is found to be reasonable compared to values presented in literature. Thus, the resin is stated to exhibit promising qualities for direct air capture.

Incremento de la s��ntesis de quitina en quistes de Entamoeba histolytica por efecto de Mg2+, Mn2+ y Co2+

Tesis (Maestr��a en Ciencias con Especialidad en Microbiolog��a) UANL

La t��cnica del procedimiento de soldar por medio del sistema de arco met��lico continuo con protecci��n de CO2

UANL