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Constantino Suarez - One of the best experts on this subject based on the ideXlab platform.
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Effect of Drying Temperature and Soaking Conditions on Wet-Milling Characteristics of Amaranth Grain
International Journal of Food Engineering, 2010Co-Authors: Andrea N. Calzetta Resio, Marcela P. Tolaba, Constantino SuarezAbstract:Amaranth Grains (Amaranthus cruentus) were air-dried at 40, 70 and 100 ºC and a moisture range from 29.5 to 10.2, dry basis (d.b.). Dried Grains were wet-milled at 53.9ºC in the presence of SO2 aqueous solution in order to obtain fractions of starch, protein and fiber. Effect of drying temperature and SO2 concentration (0.01 0.05 w/v %) on fraction yields and protein content of starch were investigated using response surface method (RSM). A factorial design including triplicate of central point was performed. Starch and protein yields decreased as drying temperature increased while fiber yield and protein content in starch fraction shown the opposite behaviour. Protein yield and protein in starch fraction were affected negatively by SO2 concentration. Interaction among studied factors was only appreciable in fiber yield where a synergic effect was observed. The optimum conditions required to maximize starch together with the minimization of protein content in starch fraction included drying temperature of 40°C with Amaranth soaking using 0.05 w/v % of SO2. These process conditions lead to 35.1 ± 1.4% of starch yield with a protein content of 1.93 ± 0.015%.
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Correlations between wet-milling characteristics of Amaranth Grain
Journal of Food Engineering, 2009Co-Authors: Andrea N. Calzetta Resio, Marcela P. Tolaba, Constantino SuarezAbstract:Abstract Relationships of acid wet-milling conditions (soaking temperature and sulfur dioxide concentration) to laboratory wet-milling characteristics (fraction yields, protein content of fractions, and recovery values) of Amaranth seeds were determined. Based on correlation coefficients (Pearson matrix), it was found that: (a) starch recovery was significantly correlated to fiber yield (r = −0.74); (b) the correlations of gluten recovery with protein content of starch (r = −0.69) and among protein contents of fiber and gluten (r = −0.63) pointed out the importance to have an efficient fiber isolation to assure satisfactory gluten yield; and (c) the solids in soaking water were correlated with protein contents of wet-milling being fractions being the coefficient value of −0.87 for gluten fraction. Principal component analysis identified three components (named as solids-leaching effect, protein-dispersion effect, and matrix-breakdown effect) that explained 95% of the total variation among wet-milling responses. The needs to recycle the processing water and the greater significance of the fraction quality over the fraction yield were revealed.
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Hydration kinetics of Amaranth Grain
Journal of Food Engineering, 2006Co-Authors: Andrea N. Calzetta Resio, Roberto J. Aguerre, Constantino SuarezAbstract:Abstract The kinetics of water uptake by Amaranth Grain soaked in plain water, SO 2 aqueous solution (0.01% and 0.02%, w/v) and SO 2 solution (0.02%, w/v) with variable concentrations of lactic acid (0.0025% and 0.0050%, v/v), covering a temperature range from 30 °C to 60 °C was investigated. The resulting kinetics data were correlated by means of Peleg’s equation. The Peleg model predicted adequately the hydration kinetics of Amaranth Grain till saturation moisture content using short-time data at the given conditions. The Peleg rate constant k 1 and Peleg constant capacity k 2 were affected by temperature and soaking conditions. The constant k 1 decreased from 50.8 to 21.3 for increasing temperature from 30 to 60 °C, while for k 2 the decreased was from 1.87 to 1.17 when soaking in plain water. Amaranth soaking in SO 2 aqueous solution gave lower k 1 than those for plain water, indicating acceleration in the absorption rate. The effect on k 2 was less marked, being the moisture saturation capacities of the Grain in plain water and SO 2 solution almost coincident. The increase of SO 2 concentration did not have practical effects on both constants k 1 and k 2 . Absorption rates for lactic acid concentration were significantly higher than those soaked only in SO 2 solutions (the constant k 1 was less in lactic acid solutions than in SO 2 solutions); the values of k 2 and consequently the saturation moisture contents were not practically affected by the presence of lactic acid in the soaking media.
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analysis of simultaneous water absorption and water starch reaction during soaking of Amaranth Grain
Journal of Food Engineering, 2005Co-Authors: Andrea N. Calzetta Resio, Roberto J. Aguerre, Constantino SuarezAbstract:Abstract The soaking process of a Grain Amaranth variety ( Amaranthus cruentus ) was investigated in water between 30 and 90 °C. A mathematical model describing simultaneous unsteady water diffusion and first-order irreversible water–starch reaction is proposed to simulate soaking process of Grains. The observed water absorption curves are used to estimate the effective diffusivities ( D ef ) and reaction rate ( k ). The values of D ef and k were between 10 −12 and 10 −11 m 2 s −1 and 10 −5 and 10 −3 s −1 , respectively. The dependence on temperature of D ef and k was evaluated through an Arrhenius type equation with two distinct activation energies for diffusion ( E D ) and reaction ( E k ) below and above 64 °C. The calculated values were E D = 31.0 kJ mol −1 and E k = 24.5 kJ mol −1 below 64 °C and E D = 53.6 kJ mol −1 and E k = 136.5 kJ mol −1 above 64 °C. These results suggest that at least, for the soaking temperatures above 64 °C, the absorption process is controlled by water–starch reactivity.
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Analysis of simultaneous water absorption and water–starch reaction during soaking of Amaranth Grain
Journal of Food Engineering, 2005Co-Authors: Andrea N. Calzetta Resio, Roberto J. Aguerre, Constantino SuarezAbstract:Abstract The soaking process of a Grain Amaranth variety ( Amaranthus cruentus ) was investigated in water between 30 and 90 °C. A mathematical model describing simultaneous unsteady water diffusion and first-order irreversible water–starch reaction is proposed to simulate soaking process of Grains. The observed water absorption curves are used to estimate the effective diffusivities ( D ef ) and reaction rate ( k ). The values of D ef and k were between 10 −12 and 10 −11 m 2 s −1 and 10 −5 and 10 −3 s −1 , respectively. The dependence on temperature of D ef and k was evaluated through an Arrhenius type equation with two distinct activation energies for diffusion ( E D ) and reaction ( E k ) below and above 64 °C. The calculated values were E D = 31.0 kJ mol −1 and E k = 24.5 kJ mol −1 below 64 °C and E D = 53.6 kJ mol −1 and E k = 136.5 kJ mol −1 above 64 °C. These results suggest that at least, for the soaking temperatures above 64 °C, the absorption process is controlled by water–starch reactivity.
Andrea N. Calzetta Resio - One of the best experts on this subject based on the ideXlab platform.
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Effect of Drying Temperature and Soaking Conditions on Wet-Milling Characteristics of Amaranth Grain
International Journal of Food Engineering, 2010Co-Authors: Andrea N. Calzetta Resio, Marcela P. Tolaba, Constantino SuarezAbstract:Amaranth Grains (Amaranthus cruentus) were air-dried at 40, 70 and 100 ºC and a moisture range from 29.5 to 10.2, dry basis (d.b.). Dried Grains were wet-milled at 53.9ºC in the presence of SO2 aqueous solution in order to obtain fractions of starch, protein and fiber. Effect of drying temperature and SO2 concentration (0.01 0.05 w/v %) on fraction yields and protein content of starch were investigated using response surface method (RSM). A factorial design including triplicate of central point was performed. Starch and protein yields decreased as drying temperature increased while fiber yield and protein content in starch fraction shown the opposite behaviour. Protein yield and protein in starch fraction were affected negatively by SO2 concentration. Interaction among studied factors was only appreciable in fiber yield where a synergic effect was observed. The optimum conditions required to maximize starch together with the minimization of protein content in starch fraction included drying temperature of 40°C with Amaranth soaking using 0.05 w/v % of SO2. These process conditions lead to 35.1 ± 1.4% of starch yield with a protein content of 1.93 ± 0.015%.
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Correlations between wet-milling characteristics of Amaranth Grain
Journal of Food Engineering, 2009Co-Authors: Andrea N. Calzetta Resio, Marcela P. Tolaba, Constantino SuarezAbstract:Abstract Relationships of acid wet-milling conditions (soaking temperature and sulfur dioxide concentration) to laboratory wet-milling characteristics (fraction yields, protein content of fractions, and recovery values) of Amaranth seeds were determined. Based on correlation coefficients (Pearson matrix), it was found that: (a) starch recovery was significantly correlated to fiber yield (r = −0.74); (b) the correlations of gluten recovery with protein content of starch (r = −0.69) and among protein contents of fiber and gluten (r = −0.63) pointed out the importance to have an efficient fiber isolation to assure satisfactory gluten yield; and (c) the solids in soaking water were correlated with protein contents of wet-milling being fractions being the coefficient value of −0.87 for gluten fraction. Principal component analysis identified three components (named as solids-leaching effect, protein-dispersion effect, and matrix-breakdown effect) that explained 95% of the total variation among wet-milling responses. The needs to recycle the processing water and the greater significance of the fraction quality over the fraction yield were revealed.
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Hydration kinetics of Amaranth Grain
Journal of Food Engineering, 2006Co-Authors: Andrea N. Calzetta Resio, Roberto J. Aguerre, Constantino SuarezAbstract:Abstract The kinetics of water uptake by Amaranth Grain soaked in plain water, SO 2 aqueous solution (0.01% and 0.02%, w/v) and SO 2 solution (0.02%, w/v) with variable concentrations of lactic acid (0.0025% and 0.0050%, v/v), covering a temperature range from 30 °C to 60 °C was investigated. The resulting kinetics data were correlated by means of Peleg’s equation. The Peleg model predicted adequately the hydration kinetics of Amaranth Grain till saturation moisture content using short-time data at the given conditions. The Peleg rate constant k 1 and Peleg constant capacity k 2 were affected by temperature and soaking conditions. The constant k 1 decreased from 50.8 to 21.3 for increasing temperature from 30 to 60 °C, while for k 2 the decreased was from 1.87 to 1.17 when soaking in plain water. Amaranth soaking in SO 2 aqueous solution gave lower k 1 than those for plain water, indicating acceleration in the absorption rate. The effect on k 2 was less marked, being the moisture saturation capacities of the Grain in plain water and SO 2 solution almost coincident. The increase of SO 2 concentration did not have practical effects on both constants k 1 and k 2 . Absorption rates for lactic acid concentration were significantly higher than those soaked only in SO 2 solutions (the constant k 1 was less in lactic acid solutions than in SO 2 solutions); the values of k 2 and consequently the saturation moisture contents were not practically affected by the presence of lactic acid in the soaking media.
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analysis of simultaneous water absorption and water starch reaction during soaking of Amaranth Grain
Journal of Food Engineering, 2005Co-Authors: Andrea N. Calzetta Resio, Roberto J. Aguerre, Constantino SuarezAbstract:Abstract The soaking process of a Grain Amaranth variety ( Amaranthus cruentus ) was investigated in water between 30 and 90 °C. A mathematical model describing simultaneous unsteady water diffusion and first-order irreversible water–starch reaction is proposed to simulate soaking process of Grains. The observed water absorption curves are used to estimate the effective diffusivities ( D ef ) and reaction rate ( k ). The values of D ef and k were between 10 −12 and 10 −11 m 2 s −1 and 10 −5 and 10 −3 s −1 , respectively. The dependence on temperature of D ef and k was evaluated through an Arrhenius type equation with two distinct activation energies for diffusion ( E D ) and reaction ( E k ) below and above 64 °C. The calculated values were E D = 31.0 kJ mol −1 and E k = 24.5 kJ mol −1 below 64 °C and E D = 53.6 kJ mol −1 and E k = 136.5 kJ mol −1 above 64 °C. These results suggest that at least, for the soaking temperatures above 64 °C, the absorption process is controlled by water–starch reactivity.
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The drying of Amaranth Grain: mathematical modeling and simulation
Brazilian Journal of Chemical Engineering, 2005Co-Authors: Andrea N. Calzetta Resio, Roberto J. Aguerre, C. SuarezAbstract:A model for isothermal diffusion of bound water was used to simulate the thin-layer drying kinetics of Amaranth Grain. The model assumes that the driving force for the transport of bound water is the gradient of spreading pressure. The gradient of spreading pressure was related to the moisture gradient using the GAB isotherm. This variation shows a relative maximum moisture content about 8% (d.b), after which the diffusion coefficient falls sharply as the moisture content is further reduced. To verify the model, drying tests of Amaranth Grain were conducted at 40 to 70oC in a laboratory drier from 32.5 to 6% moisture (d.b.). Equilibrium moisture contents were also determined using an electronic hygrometer at temperatures and relative humidities corresponding to drying conditions. The applicability of the model to simulation of drying curves was satisfactory in the full range of moisture.
Roberto J. Aguerre - One of the best experts on this subject based on the ideXlab platform.
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Hydration kinetics of Amaranth Grain
Journal of Food Engineering, 2006Co-Authors: Andrea N. Calzetta Resio, Roberto J. Aguerre, Constantino SuarezAbstract:Abstract The kinetics of water uptake by Amaranth Grain soaked in plain water, SO 2 aqueous solution (0.01% and 0.02%, w/v) and SO 2 solution (0.02%, w/v) with variable concentrations of lactic acid (0.0025% and 0.0050%, v/v), covering a temperature range from 30 °C to 60 °C was investigated. The resulting kinetics data were correlated by means of Peleg’s equation. The Peleg model predicted adequately the hydration kinetics of Amaranth Grain till saturation moisture content using short-time data at the given conditions. The Peleg rate constant k 1 and Peleg constant capacity k 2 were affected by temperature and soaking conditions. The constant k 1 decreased from 50.8 to 21.3 for increasing temperature from 30 to 60 °C, while for k 2 the decreased was from 1.87 to 1.17 when soaking in plain water. Amaranth soaking in SO 2 aqueous solution gave lower k 1 than those for plain water, indicating acceleration in the absorption rate. The effect on k 2 was less marked, being the moisture saturation capacities of the Grain in plain water and SO 2 solution almost coincident. The increase of SO 2 concentration did not have practical effects on both constants k 1 and k 2 . Absorption rates for lactic acid concentration were significantly higher than those soaked only in SO 2 solutions (the constant k 1 was less in lactic acid solutions than in SO 2 solutions); the values of k 2 and consequently the saturation moisture contents were not practically affected by the presence of lactic acid in the soaking media.
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analysis of simultaneous water absorption and water starch reaction during soaking of Amaranth Grain
Journal of Food Engineering, 2005Co-Authors: Andrea N. Calzetta Resio, Roberto J. Aguerre, Constantino SuarezAbstract:Abstract The soaking process of a Grain Amaranth variety ( Amaranthus cruentus ) was investigated in water between 30 and 90 °C. A mathematical model describing simultaneous unsteady water diffusion and first-order irreversible water–starch reaction is proposed to simulate soaking process of Grains. The observed water absorption curves are used to estimate the effective diffusivities ( D ef ) and reaction rate ( k ). The values of D ef and k were between 10 −12 and 10 −11 m 2 s −1 and 10 −5 and 10 −3 s −1 , respectively. The dependence on temperature of D ef and k was evaluated through an Arrhenius type equation with two distinct activation energies for diffusion ( E D ) and reaction ( E k ) below and above 64 °C. The calculated values were E D = 31.0 kJ mol −1 and E k = 24.5 kJ mol −1 below 64 °C and E D = 53.6 kJ mol −1 and E k = 136.5 kJ mol −1 above 64 °C. These results suggest that at least, for the soaking temperatures above 64 °C, the absorption process is controlled by water–starch reactivity.
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The drying of Amaranth Grain: mathematical modeling and simulation
Brazilian Journal of Chemical Engineering, 2005Co-Authors: Andrea N. Calzetta Resio, Roberto J. Aguerre, C. SuarezAbstract:A model for isothermal diffusion of bound water was used to simulate the thin-layer drying kinetics of Amaranth Grain. The model assumes that the driving force for the transport of bound water is the gradient of spreading pressure. The gradient of spreading pressure was related to the moisture gradient using the GAB isotherm. This variation shows a relative maximum moisture content about 8% (d.b), after which the diffusion coefficient falls sharply as the moisture content is further reduced. To verify the model, drying tests of Amaranth Grain were conducted at 40 to 70oC in a laboratory drier from 32.5 to 6% moisture (d.b.). Equilibrium moisture contents were also determined using an electronic hygrometer at temperatures and relative humidities corresponding to drying conditions. The applicability of the model to simulation of drying curves was satisfactory in the full range of moisture.
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Analysis of simultaneous water absorption and water–starch reaction during soaking of Amaranth Grain
Journal of Food Engineering, 2005Co-Authors: Andrea N. Calzetta Resio, Roberto J. Aguerre, Constantino SuarezAbstract:Abstract The soaking process of a Grain Amaranth variety ( Amaranthus cruentus ) was investigated in water between 30 and 90 °C. A mathematical model describing simultaneous unsteady water diffusion and first-order irreversible water–starch reaction is proposed to simulate soaking process of Grains. The observed water absorption curves are used to estimate the effective diffusivities ( D ef ) and reaction rate ( k ). The values of D ef and k were between 10 −12 and 10 −11 m 2 s −1 and 10 −5 and 10 −3 s −1 , respectively. The dependence on temperature of D ef and k was evaluated through an Arrhenius type equation with two distinct activation energies for diffusion ( E D ) and reaction ( E k ) below and above 64 °C. The calculated values were E D = 31.0 kJ mol −1 and E k = 24.5 kJ mol −1 below 64 °C and E D = 53.6 kJ mol −1 and E k = 136.5 kJ mol −1 above 64 °C. These results suggest that at least, for the soaking temperatures above 64 °C, the absorption process is controlled by water–starch reactivity.
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Drying characteristics of Amaranth Grain
Journal of Food Engineering, 2004Co-Authors: Andrea N. Calzetta Resio, Roberto J. Aguerre, Constantino SuarezAbstract:Thin-layer drying of Amaranth Grain was conducted at 40, 50, 60 and 70 °C and a moisture range from about 32.5% to 5.0%, dry basis. A mathematical model based on Fick' s second law of diffusion with variable diffusion coefficient for spherically shaped Grain was used to predict the drying behavior of the Grain. An analytical expression describing the variation of the diffusion coefficient with moisture was derived, based on the fact that the ratio of activation energy for diffusion and the heat of desorption is a constant value and equal to 0.5. A correlation describing the activation energy of the drying process with moisture content and temperature is established.
Marcela P. Tolaba - One of the best experts on this subject based on the ideXlab platform.
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Ball Milling of Amaranth Starch-Enriched Fraction. Changes on Particle Size, Starch Crystallinity, and Functionality as a Function of Milling Energy
Food and Bioprocess Technology, 2014Co-Authors: Diego F. Roa, Patricio R. Santagapita, M. Pilar Buera, Marcela P. TolabaAbstract:Starch-enriched fractions of Amaranth Grain were obtained from planetary ball milling and subsequently studied for particle size reduction, hydration properties, and crystallinity loss. Wide-angle X-ray scattering (WAXS) was used to evaluate the crystalline of starch-enriched fractions, using an iterative smoothing algorithm to estimate amorphous background scattering. This methodology was then used to determine initial crystallinity and monitor crystallinity loss during this process. The attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) showed that ball-milling treatment significantly decreased ( p
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Effect of Drying Temperature and Soaking Conditions on Wet-Milling Characteristics of Amaranth Grain
International Journal of Food Engineering, 2010Co-Authors: Andrea N. Calzetta Resio, Marcela P. Tolaba, Constantino SuarezAbstract:Amaranth Grains (Amaranthus cruentus) were air-dried at 40, 70 and 100 ºC and a moisture range from 29.5 to 10.2, dry basis (d.b.). Dried Grains were wet-milled at 53.9ºC in the presence of SO2 aqueous solution in order to obtain fractions of starch, protein and fiber. Effect of drying temperature and SO2 concentration (0.01 0.05 w/v %) on fraction yields and protein content of starch were investigated using response surface method (RSM). A factorial design including triplicate of central point was performed. Starch and protein yields decreased as drying temperature increased while fiber yield and protein content in starch fraction shown the opposite behaviour. Protein yield and protein in starch fraction were affected negatively by SO2 concentration. Interaction among studied factors was only appreciable in fiber yield where a synergic effect was observed. The optimum conditions required to maximize starch together with the minimization of protein content in starch fraction included drying temperature of 40°C with Amaranth soaking using 0.05 w/v % of SO2. These process conditions lead to 35.1 ± 1.4% of starch yield with a protein content of 1.93 ± 0.015%.
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Correlations between wet-milling characteristics of Amaranth Grain
Journal of Food Engineering, 2009Co-Authors: Andrea N. Calzetta Resio, Marcela P. Tolaba, Constantino SuarezAbstract:Abstract Relationships of acid wet-milling conditions (soaking temperature and sulfur dioxide concentration) to laboratory wet-milling characteristics (fraction yields, protein content of fractions, and recovery values) of Amaranth seeds were determined. Based on correlation coefficients (Pearson matrix), it was found that: (a) starch recovery was significantly correlated to fiber yield (r = −0.74); (b) the correlations of gluten recovery with protein content of starch (r = −0.69) and among protein contents of fiber and gluten (r = −0.63) pointed out the importance to have an efficient fiber isolation to assure satisfactory gluten yield; and (c) the solids in soaking water were correlated with protein contents of wet-milling being fractions being the coefficient value of −0.87 for gluten fraction. Principal component analysis identified three components (named as solids-leaching effect, protein-dispersion effect, and matrix-breakdown effect) that explained 95% of the total variation among wet-milling responses. The needs to recycle the processing water and the greater significance of the fraction quality over the fraction yield were revealed.
Pierre Christen - One of the best experts on this subject based on the ideXlab platform.
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characterization of volatile compounds produced by rhizopus strains grown on agro industrial solid wastes
Bioresource Technology, 2000Co-Authors: Pierre Christen, Sergio Revah, A Bramorski, Carlos Ricardo SoccolAbstract:Abstract Four edible Rhizopus strains were cultivated on eight combinations of solid agro-industrial wastes (cassava bagasse, apple pomace), soyabean, Amaranth Grain and soyabean oil. Significant differences in growth were observed among strains on the different media studied. The medium containing cassava bagasse with soyabean (5:5 w/w) gave the highest CO2 production, while Rhizopus oryzae ATCC 34612 was the best producer of volatiles. The aromas of the cultures were light and rather pleasant. The Amaranth medium with mineral salts solution produced the highest amount of volatile compounds (VC), demonstrating that the aroma of fermented solid substrates can be improved. The VC production was very rapid, attaining, in most of the cases, its maximum around the first day of culture. These maxima markedly varied according to the medium used.
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Production of volatile compounds by the edible fungus Rhizopus oryzae during solid state cultivation on tropical agro-industrial substrates
Biotechnology Letters, 1998Co-Authors: Adriana Bramorski, Pierre Christen, Martha Ramirez, Carlos R. Soccol, Sergio RevahAbstract:When Rhizopus oryzae was grown on medium containing cassava bagasse plus soybean meal (5:5 w/w), CO2 production was at its highest (200 ml.l–1) while highest volatile metabolite production was with Amaranth Grain as substrate (282.8 ml.l–1). In the headspace, ethanol was the most abundant compound (more than 80%). Acetaldehyde, 1-propanol, ethyl acetate, ethyl propionate and 3-methyl butanol were also present. CO2 and volatile metabolite productions reached their maxima around 20 h and 36 h, respectively. © Rapid Science Ltd. 1998