Dehydrated sorghum flour ("ogi") is useful as additional ingredient in certain food and pharmaceutical formulation, this could be obtained by soaking sorghum in water for 3 to 4 days, wet milling the soaked materi...Dehydrated sorghum flour ("ogi") is useful as additional ingredient in certain food and pharmaceutical formulation, this could be obtained by soaking sorghum in water for 3 to 4 days, wet milling the soaked material, and fermentation for another 3 to 4 days. Typically, the fermented product is boiled into a pap or cooked into a stiff porridge. However, the fermented product can not be easily handled or stored and does not have a long shelf life (typically less than a week). Dehydrating the fermented product into flour is one of the ways that is being employed to overcome these problems. Equilibrium moisture content (EMC) of dehydrated sorghum flour (aka "ogi") was therefore determined at two temperatures of 25℃ and 40℃ and four salt solutions. Zinc chloride (ZnCl2), potassium acetate (KC2H3O2), calcium chloride (CaCl2) and sodium chloride (NaCl) salts were prepared to correspond to equilibrium relative humidities of 10.0% to 75.4%. The moisture sorption characteristics of the sorghum product showed the characteristics S-shaped sorption isotherm curve that is typically obtained for agricultural products. The equilibrium data and the monomolccular layer moisture content values were estimated using the Brunauer-Emmett-Teller (BET) equation. The moisture content range for optimum storage of the dehydrated sorghum flour lies between 2.84% to 3.69% at 25℃ and 6.84% and 7.67% at 40℃. The information obtained from this study will help in the design and selection of storage and packaging systems for dehydrated sorghum flour.展开更多
The purpose of this study is to determine the morphological, microstructural characteristics and water diffusion parameters of the Canarium schweinfurthii (CS) shellnut. This work is part of a vast project to valorize...The purpose of this study is to determine the morphological, microstructural characteristics and water diffusion parameters of the Canarium schweinfurthii (CS) shellnut. This work is part of a vast project to valorize the above-mentioned cores for possible industrial use as charges in composites or abrasives materials. The study was based on the characterization of intrinsic physical characteristics of the coreshells scanning electron microscopic (SEM) observations desorption, adsorption and absorption kinetics. The water diffusion phenomenon was modeled and it appears that the Page model well predicted the kinetic of drying, absorption and adsorption. The effective diffusion coefficient and the energy of activation were calculated at three isothermal temperatures (50<span style="white-space:nowrap;">°</span>C, 70<span style="white-space:nowrap;">°</span>C and 90<span style="white-space:nowrap;">°</span>C). There was a tendency for hysteresis in the sorption-desorption cycles. These results strongly predicted the possibility of using these products as a filler in composites, clay building materials and cement because of their high water diffusion stability on a macroscopic scale.展开更多
Moisture sorption isotherms and thermodynamic properties of Camellia oleifera seeds as influenced by oil content were investigated.Moisture desorption and adsorption isotherms of Camellia oleifera seeds,kernels and sh...Moisture sorption isotherms and thermodynamic properties of Camellia oleifera seeds as influenced by oil content were investigated.Moisture desorption and adsorption isotherms of Camellia oleifera seeds,kernels and shells from three varieties were determined using constant temperature and humidity chamber method at different temperatures(10°C,25°C,and 40°C)with water activity ranging from 0.20 to 0.90.Six selected mathematic models were employed to fit the experimental data.The Peleg model gave the best results for both seeds and kernels and Langmuir model was the best for shells.The difference of equilibrium moisture contents at the same water activities during desorption and adsorption indicated the occurrence of hysteresis of adsorption processes and the equilibrium moisture contents tended to decrease with the increasing oil content and temperature.The binding energy and average capacity per unit mass decreased with increasing temperature and oil content.The relationships between water activity and the logarithm of sorption activity showed the capillary porous body characteristics of the seeds.展开更多
文摘Dehydrated sorghum flour ("ogi") is useful as additional ingredient in certain food and pharmaceutical formulation, this could be obtained by soaking sorghum in water for 3 to 4 days, wet milling the soaked material, and fermentation for another 3 to 4 days. Typically, the fermented product is boiled into a pap or cooked into a stiff porridge. However, the fermented product can not be easily handled or stored and does not have a long shelf life (typically less than a week). Dehydrating the fermented product into flour is one of the ways that is being employed to overcome these problems. Equilibrium moisture content (EMC) of dehydrated sorghum flour (aka "ogi") was therefore determined at two temperatures of 25℃ and 40℃ and four salt solutions. Zinc chloride (ZnCl2), potassium acetate (KC2H3O2), calcium chloride (CaCl2) and sodium chloride (NaCl) salts were prepared to correspond to equilibrium relative humidities of 10.0% to 75.4%. The moisture sorption characteristics of the sorghum product showed the characteristics S-shaped sorption isotherm curve that is typically obtained for agricultural products. The equilibrium data and the monomolccular layer moisture content values were estimated using the Brunauer-Emmett-Teller (BET) equation. The moisture content range for optimum storage of the dehydrated sorghum flour lies between 2.84% to 3.69% at 25℃ and 6.84% and 7.67% at 40℃. The information obtained from this study will help in the design and selection of storage and packaging systems for dehydrated sorghum flour.
文摘The purpose of this study is to determine the morphological, microstructural characteristics and water diffusion parameters of the Canarium schweinfurthii (CS) shellnut. This work is part of a vast project to valorize the above-mentioned cores for possible industrial use as charges in composites or abrasives materials. The study was based on the characterization of intrinsic physical characteristics of the coreshells scanning electron microscopic (SEM) observations desorption, adsorption and absorption kinetics. The water diffusion phenomenon was modeled and it appears that the Page model well predicted the kinetic of drying, absorption and adsorption. The effective diffusion coefficient and the energy of activation were calculated at three isothermal temperatures (50<span style="white-space:nowrap;">°</span>C, 70<span style="white-space:nowrap;">°</span>C and 90<span style="white-space:nowrap;">°</span>C). There was a tendency for hysteresis in the sorption-desorption cycles. These results strongly predicted the possibility of using these products as a filler in composites, clay building materials and cement because of their high water diffusion stability on a macroscopic scale.
基金The authors acknowledge that this work was financially supported by the Gannan Oil Tea Camellia Industry Collaborative Innovation Center(Grant No.YP201610).
文摘Moisture sorption isotherms and thermodynamic properties of Camellia oleifera seeds as influenced by oil content were investigated.Moisture desorption and adsorption isotherms of Camellia oleifera seeds,kernels and shells from three varieties were determined using constant temperature and humidity chamber method at different temperatures(10°C,25°C,and 40°C)with water activity ranging from 0.20 to 0.90.Six selected mathematic models were employed to fit the experimental data.The Peleg model gave the best results for both seeds and kernels and Langmuir model was the best for shells.The difference of equilibrium moisture contents at the same water activities during desorption and adsorption indicated the occurrence of hysteresis of adsorption processes and the equilibrium moisture contents tended to decrease with the increasing oil content and temperature.The binding energy and average capacity per unit mass decreased with increasing temperature and oil content.The relationships between water activity and the logarithm of sorption activity showed the capillary porous body characteristics of the seeds.