Biomass Gasification Using Carbon Dioxide: Effect of Temperature, CO2/C Ratio, and the Study of Reactions Influencing the Process

Climate change is primarily manifested by elevated temperature and carbon dioxide (CO2) levels and is projected to provide suitable cultivation grounds for pests and pathogens in the otherwise unsuitable regions. The impacts of climate change have been predicted in many parts of the world, which could threaten global food safety and food security. The aim of the present work was therefore to examine the interacting effects of water activity (aw) (0.92, 0.95, 0.98 aw), CO2 (400, 800, 1200 ppm) and temperature (30, 35 °C and 30, 33 °C for Fusarium verticillioides and F. graminearum, respectively) on fungal growth and mycotoxin production of acclimatised isolates of F. verticillioides and F. graminearum isolated from maize. To determine fungal growth, the colony diameters were measured on days 1, 3, 5, and 7. The mycotoxins produced were quantified using a quadrupole-time-of-flight mass spectrometer (QTOF-MS) combined with ultra-high-performance liquid chromatography (UHPLC) system. For F. verticillioides, the optimum conditions for growth of fumonisin B1 (FB1), and fumonisin B2 (FB2) were 30 °C + 0.98 aw + 400 ppm CO2. These conditions were also optimum for F. graminearum growth, and zearalenone (ZEA) and deoxynivalenol (DON) production. Since 30 °C and 400 ppm CO2 were the baseline treatments, it was hence concluded that the elevated temperature and CO2 levels tested did not seem to significantly impact fungal growth and mycotoxin production of acclimatised Fusarium isolates. To the best of our knowledge thus far, the present work described for the first time the effects of simulated climate change conditions on fungal growth and mycotoxin production of acclimatised isolates of F. verticillioides and F. graminearum.

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Supercritical Fluid Extraction of Polygonum cuspidatum and Subsequent Isolation by Simulated Moving Bed Chromatography

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.704.18 ◽

2013 ◽

Vol 704 ◽

pp. 18-30

Author(s):

Ming Tsai Liang ◽

Ru Chien Liang ◽

Shu Qi Yu ◽

Ri An Yan ◽

Ku Yuan Liang

Keyword(s):

Carbon Dioxide ◽

Crude Extract ◽

Operating Conditions ◽

Effect Of Temperature ◽

Simulated Moving Bed ◽

Polygonum Cuspidatum ◽

Two Stage ◽

Moving Bed ◽

Second Stage ◽

Simulated Moving Bed Chromatography

In this work, supercritical carbon dioxide with ethanol as cosolvent was employed to extract bioactive compounds fromPolygonum Cuspidatum. Effect of temperature for 40 and 50 C on the extraction at 35 MPa was examined. It was found that extraction at 50 C resulted in high yield. A two-stage extraction at 50 C and 35 MPa was then designed to investigate effect of cosolvent on the recovery of resveratrol and emodin. The first stage extraction by solely using carbon dioxide can rarely extract resveratrol, but adding ethanol as cosolvent in the second stage significantly increases the extraction of resverarol and emodin. The crude extract obtained in the second stage was very stable against agglomeration and precipitation, because the first stage extraction helped to remove impurities from thePolygonum Cuspidatum. The stable crude extract was subsequently used as the feed for the SMB (simulated moving bed) separation. In this work, experimental validation was completed by solely using single SMB to isolate resveratrol, emodin, and physcion from the crude extract. As conducting the SMB experiments, the Triangle theory was used to help to determine the separable operating conditions. From the discussion of the experimental results, the criterion to obtain the pure resveratrol and physcion, and the concentrated emodin were depicted. Since both the extraction and the purification are conducted at low temperature, the bioactivity of the produced natural products will totally be preserved. The two-stage extraction and subsequent purification in this paper will provide greener and effective alternative for the development of botanical drugs.

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Inactivation of Escherichia coli (ATCC 4157) in Diluted Apple Cider by Dense-Phase Carbon Dioxide

Journal of Food Protection ◽

10.4315/0362-028x-69.1.12 ◽

2006 ◽

Vol 69 (1) ◽

pp. 12-16 ◽

Cited By ~ 40

Author(s):

GURBUZ GUNES ◽

L. K. BLUM ◽

J. H. HOTCHKISS

Keyword(s):

Escherichia Coli ◽

Carbon Dioxide ◽

High Sensitivity ◽

Effect Of Temperature ◽

Dense Phase ◽

Apple Cider ◽

E Coli ◽

Product Ratio ◽

Log Reduction ◽

Temperature And Pressure

Dense-phase carbon dioxide (CO2) treatments in a continuous flow through system were applied to apple cider to inactivate Escherichia coli (ATCC 4157). A response surface design with factors of the CO2/product ratio (0, 70, and 140 g/kg), temperature (25, 35, and 45°C), and pressure (6.9, 27.6, and 48.3 MPa) were used. E. coli was very sensitive to dense CO2 treatment, with a more than 6-log reduction in treatments containing 70 and 140 g/kg CO2, irrespective of temperature and pressure. The CO2/product ratio was the most important factor affecting inactivation rate of E. coli. No effect of temperature and pressure was detected because of high sensitivity of the cells to dense CO2. Dense CO2 could be an alternative pasteurization treatment for apple cider. Further studies dealing with the organoleptic quality of the product are needed.

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