showing 6 related works from this author
Modeling small‐scale cassava starch extraction. Simulation of the reduction of water consumption through a recycling process
2010
International audience; The purpose of this study was to model the extraction unit operation of the cassava starch manufacturing process and to propose a realistic recycling simulation in order to reduce the volumes of effluents. The model was developed from reactors which are commonly used for cassava starch extraction at a household scale in Vietnam. The reactors were tested using inflow starch as a marker at the beginning of the batch process. The experimental residence time distribution (RTDexp) was calculated by the outflow of the starch concentration. Using Matlab®, the RTDexp was compared to the theoretical residence time distribution (RTDth). The dynamic model obtained was built up …
Water relations of solid state fermentation
1996
International audience; The hydration level of the culture medium affects drastically the physiology of microorganisms. Thermodynamic properties of water in a solid-state medium such as water potential or water activity, and dynamic properties of water such as water diffusion are examined. The mechanisms of water transfer between intra and extracellular media are discussed, and different results on the incidence of the water activity level on the survival, growth and metabolism of microorganisms are reported. Optimal macroscopic and microscopic growth, or metabolic production by fungi occurs in media with water activity values lower than those of classical cultivation media (≈ 1). In solid …
Cassava starch processing at small scale in North Vietnam
2008
International audience; In Northern Vietnam, small-scale cassava starch processing is conducted in densely populated craft villages, where processors face difficulties to expand their activities. Three different processing systems were studied among a cluster of three communes in the Red River Delta, producing up to 430 t of starch (at 55% dry matter) per day. The first system, type A, is a cylindrical rasper and a manual sieve, the second, type B, is a cylindrical rasper and stirring-filtering machine and the third, type C, used equipment for both the rasping and filtering stages. Moisture, starch, crude fibers and ash content analysis were carried out on samples collected from the A-B-C m…
Fluorescent probes to evaluate the physiological state and activity of microbial biocatalysts: A guide for prokaryotic and eukaryotic investigation
2008
International audience; Many fluorescent techniques are employed to evaluate the viability and activity of microbial cells used in biotechnology. These techniques are sometimes complex and the interpretation of results opened to misunderstanding. Moreover, new developments are constantly proposed especially concerning a more accurate evaluation of the state of the cells including eukaryotic microorganisms. This paper aims at presenting to biotechnologists unfamiliar with fluorescence the principles of these methods and the related possible pitfalls. It focuses on probes of the physical (integrity and fluidity) and energetical (intracellular pH and membrane potential) state of the cell membr…
Thermodynamics of yeast cell osmoregulation: Passive mechanisms
1996
International audience; The response of yeast cells to osmotic pressure variations of the medium were studied through the kinetics of cell-volume modifications corresponding to the mass transfer of water and solutes. Osmotic variations were made by modification of the concentration of an external binary solution (polyol/water) without nutritive components. Two phases were distinguished in the thermodynamic response. A transient phase following an osmotic shift, which is characterised by rapid water transfer across the cell membrane and whose kinetics determine cell viability; then, a steady-state phase is reached when the cell volume becomes quasi-constant. The response of the cell during t…
Viability of lactic bacteria submitted to dehydration: Importance of the dehydration kinetics \textbar Servie des bactéries lactiques soumises à la d…
1998
International audience; no abstract