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E C Clausen

Publications and source records attributed to E C Clausen.

4 recordsLinked to original sources
PubMed2001

Heat transfer properties, moisture loss, product yield, and soluble proteins in chicken breast patties during air convection cooking.

Chicken breast patties were processed in an air convection oven at air temperatures of 149 to 218 C, air velocities of 7.1 to 12.7 m3/min, and air relative humidities of 40 to 95%. The air humidity was controlled via introducing steam into the oven. The patties were processed to a final center temperature of 50 to 80 C. Heat flux, heat transfer coefficient, moisture loss in the cooked chicken patties, the product yield, and the changes of soluble proteins in the product were evaluated for the cooking system. During cooking, heat flux varied with the processing time. Heat flux increased with increasing air humidity. The effective heat transfer coefficient was obtained for different cooking conditions. Air humidity in the oven affected the heat transfer coefficient. The moisture loss in the cooked products increased with increasing the final product temperature and the oven air temperature. The soluble proteins in the cooked patties decreased with increasing the final product temperature. Increasing humidity increased heat transfer coefficient and therefore reduced cooking time. Reducing oven temperature, reducing internal temperature, and increasing air humidity increased the product yield. Soluble proteins might be used as an indicator for the degree of cooking. The results from this study are important for evaluating commercial thermal processes and improving product yields.

Animals↗
PubMed1991

Performance of trickle-bed bioreactors for converting synthesis gas to methane.

Carbon monoxide, H2, and CO2 in synthesis gas can be converted to CH4 by employing a triculture of Rhodospirillum rubrum, Methanosarcina barkeri, and Methanobacterium formicicum. Trickle-bed reactors have been found to be effective for this conversion because of their high mass-transfer coefficients. This paper compares results obtained for the conversion of synthesis gas to CH4 in 5-cm- and 16.5-cm-diameter trickle-bed reactors. Mass-transfer and scale-up parameters are defined, and light requirements for R. rubrum are considered in bioreactor design.

Biotechnology↗
PubMed1987

Maximizing productivity in an immobilized cell reactor.

A vertical immobilized cell reactor employing Saccharomyces cerevisiae cross-linked to a gelatin support with glutaraldehyde has proven to be an effective system to achieve high cell concentrations and high dilution rates. The reactor is very stable over long periods of time, during which the cell concentration increases continuously without achieving steady state. Therefore, periodic regeneration by gas purging is required to remove excess biomass from the interstitial spaces. The glucose concentrations along the reactor follow an exponential profile when plotted as a function of the true residence time. Such profiles are a function of the initial glucose concentration fed to the system. The overall productivity of the reactor is a function of the flow rate and the inlet glucose concentration. For a 99% conversion, the maximum overall productivity is obtained at a substrate concentration of between 15% and 20%. Theoretical cell profiles were obtained and they indicate that mass transfer is promoted at high substrate concentrations and flow rates. The performance of a variety of packing materials having different shapes and materials of construction were compared in a vertical packed bed immobilized cell reactor. With other parameters being constant, the performance of the reactor is dominated by the quantity of cells present. The packing that has the highest surface area per volume of bed yields the most extensive monolayer and gives faster reactor start-up. Packing materials having high biomass loading rates are desirable at prolonged operating periods when growth beyond the monolayer occurs. Ultimately, the packing with the highest initial porosity would be capable of loading the highest cell volume, provided that sufficient interstitial spaces were provided for cell entrapment. When the immobilized cell reactor is operated in the horizontal position, CO2 holdup is decreased, as is evidenced by an increase in liquid holdup. However, the horizontal and vertical reactors showed almost identical substrate profiles at constant cell densities. In addition, under prolonged operation, the performance of the horizontal reactor decayed after several days, while the vertical reactor remained stable for over 40 days. The improved operation of this type of column in the vertical position is attributed to the necessary promotion of mass transfer with CO2 evolution and better liquid distribution. The addition of fatty acids to the media for an ICR results in limiting growth and increasing productivity. Overgrowth can be minimized, thus allowing longer periods of operation without regeneration.(ABSTRACT TRUNCATED AT 400 WORDS)

Biotechnology↗