Search results for "Reduction potential"
showing 6 items of 6 documents
Monitoring pH and ORP in a SHARON reactor
2011
This paper analyses the valuable information provided by the on-line measurements of pH and oxidation reduction potential (ORP) in a continuous single high ammonia removal over nitrite (SHARON) reactor. A laboratory-scale SHARON reactor equipped with pH, ORP, electric conductivity and dissolved oxygen (DO) probes has been operated for more than one year. Nitrogen removal over nitrite has been achieved by adding methanol at the beginning of anoxic stages. Time evolution of pH and ORP along each cycle allows identifying the decrease in nitritation rate when ammonia is consumed during the aerobic phase and the end of the denitrification process during the anoxic phase. Therefore, monitoring pH…
Impact of oxidoreduction potential and of gas bubbling on rheological properties of non-fat yoghurt
2010
International audience; The aim of this work was to study the effect of different gaseous conditions on the physico-chemical properties of yoghurt. Four conditions of oxidoreduction potential (Eh7), +433 mV (milk gassed with air), +405 mV (ungassed milk), +283 mV (milk gassed with N2) and −349 mV (milk gassed with N2–H2) were applied to milk. The rheological properties and microstructure of these yoghurts were determined by measuring apparent viscosity, whey separation (WS) and using confocal laser scanning microscopy. Exopolysaccharide (EPS) production by lactic acid bacteria (LAB) was also studied, and production was increased for extreme Eh7 values: the highest values were obtained for a…
Screening of lactic acid bacteria for reducing power using a tetrazolium salt reduction method on milk agar.
2013
WOS:000315703100020 ; www.elsevier.com/locate/jbiosc; International audience; Reducing activity is a physiological property of lactic acid bacteria (LAB) of technological importance. We developed a solid medium with tetrazolium dyes enabling weakly and strongly reducing LAB to be discriminated. It was used to quantify populations in a mixed culture (spreading method) and screen strains (spot method).
Effect of oxidoreduction potential on aroma biosynthesis by lactic acid bacteria in nonfat yogurt
2011
; The aim of this study was to investigate the effect of oxidoreduction potential (Eh) on the biosynthesis of aroma compounds by lactic acid bacteria in non-fat yogurt. The study was done with yogurts fermented by Lactobacillus bulgaricus and Streptococcus thermophilus. The Eh was modified by the application of different gaseous conditions (air, nitrogen, and nitrogen/hydrogen). Acetaldehyde, dimethyl sulfide, diacetyl, and pentane-2,3-dione, as the major endogenous odorant compounds of yogurt, were chosen as tracers for the biosynthesis of aroma compounds by lactic acid bacteria. Oxidative conditions favored the production of acetaldehyde, dimethyl sulfide, and diketones (diacetyl and pen…
Impact of oxydoreduction potential on biosynthesis of volatile compounds in acid skim milk gel: identification and quantification
2008
International audience; Oxydoreduction potential (Eh) is an environmental parameter which defines balances between oxidant species (acceptors of electrons) and reduced species (donors of electrons) of a medium. It may modify the growth capacity of microorganisms, the metabolic fluxes, participate to the quality of fermented products (2, 6, 7) and affect the production and/or stability of volatile compounds (3,5). (...)
Contribution à l'étude des « goûts de lumière » dans le vin de champagne. II. Influence de la lumière sur le potentiel d'oxydoreduction. Corrélation …
1978
<p style="text-align: justify;">Les auteurs déterminent les potentiels d'oxydoréduction de nombreux vins de champagne avant et après la prise de mousse. Ils précisent la relation, par éclairement de vins dégorgés et non dégorgés, entre l'apparition de « goût de lumière » et le potentiel d'oxydoréduction. Ils donnent les longueurs d'onde responsables des « goûts de lumière ».</p><p style="text-align: justify;">+++</p><p style="text-align: justify;">The oxydoreduction potentials are determined for a number of wines of champagne before and after the second prise de mousse fermentation. By illuminating disgorged and non disgorged wines, the authors of this article …