Several different kinds of extractive distillation agents were investigated to affect the separat... more Several different kinds of extractive distillation agents were investigated to affect the separation of three binary liquid mixtures, isopropyl ether-acetone, methyl acetate-methanol, and isopropyl ethermethyl ethyl ketone. Because of the small size of the extractive distillation column, relative volatilities were assumed constant and the Fenske equation was used to calculate the relative volatilities and the number of minimum theoretical plates. Dimethyl sulfoxide was found to be a good extractive distillation agent. Extractive distillation when employing a proper agent not only negated the azeotropes of the above mixtures, but also improved the efficiency of separation. This process could reverse the relative volatility of isopropyl ether and acetone. This reversion was also found in the system of methyl acetate and methanol when nitrobenzene was the agent. However, normal distillation curves were obtained for the system of isopropyl ether and methyl ethyl ketone undergoing extractive distillation. In the system of methyl acetate and methanol, the relative volatility decreased as the agents' carbon number increased when glycols were used as the agents. In addition, the oxygen number and the locations of hydroxyl groups in the glycols used were believed to affect the values of relative volatility. An appreciable amount of agent must be maintained in the column to affect separation. When dimethyl sulfoxide was an agent for the three systems studied, the relative volatility increased as the addition rate increased. V
ABSTRACTStarches from nine varieties of rice, including four indica, three japonica, and two waxy... more ABSTRACTStarches from nine varieties of rice, including four indica, three japonica, and two waxy cultivars, were used for the investigation of the correlation between retrogradation and water mobility. Retrogradation and water mobility were analyzed by differential scanning calorimetry (DSC) and nuclear magnetic resonance (NMR) and expressed as enthalpy change (ΔH) and differential relaxation rate (ΔR2) for water‐17O. Water contents were measured by DSC and Karl‐Fischer methods. The results indicated that three different profiles, based on amylose content, were observed for the ΔH changes of rice starch cooks during storage. They fit well to the nonlinear regression equations of exponential rise to maximum and exponential growth models. The water content, as measured with DSC, decreased during storage but increased as measured with the Karl‐Fischer method. This discrepancy might be attributed to the different characteristics of water measured by the two methods. The ΔR2 of rice sta...
This study investigated the interrelationship between Lycium barbarum (goji) and gene expression ... more This study investigated the interrelationship between Lycium barbarum (goji) and gene expression in mouse spleen. Oligomicroarray technology was employed to explore the comprehensive response of gene expression and to screen candidate marker genes in the spleens of mice fed a goji suspension. Goji was micronized by media milling and then used to evaluate the effect of size reduction. The average diameter of nano/submicrometer goji was about 100 nm, which exhibited no cytotoxicity to cell lines IEC-6 (rat normal small intestinal cell line) and Caco-2 (human colon adenocarcinoma cell line). It was found that three genes, TNF, Nfkb1, and Bcl-2, were up-regulated and two genes, APAF-1 and caspase-3, were down-regulated by goji. This phenomenon could be helpful for cytoprotection when cells undergo stress or damage that induces the apoptotic pathway. Size reduction into nano/submicrometer scale enhanced bioactivity.
Cellulose is the most common organic compound on Earth. It is not digestible by human and is ofte... more Cellulose is the most common organic compound on Earth. It is not digestible by human and is often referred to as dietary fiber' or 'roughage', acting as a hydrophilic bulking agent for feces. Nevertheless, the pliable but strong characteristics limit the applications of cellulose in food. Size reduction would be an attractive method to broaden the utilization of cellulose. Nano/submicron scale cellulose particles have been prepared by using media mill. The rheological behavior media-milled cellulose-suspension has been investigated using a dynamic rheometer. Cotton cellulose, with a volume mean diameter 33.19 micron, was used as the raw material in this study. The diameter of cellulose was reduced to nano/submicron scale as determined by dynamic laser light measurement and illustrated by TEM. Both concentration and milling time affected the average particle size. In general, increasing milling time reduced the particle size. After being milled for 180 min, the highest c...
GC/Ion-Trap MS has been employed to determine the acrylamide content in some Chinese foods. The b... more GC/Ion-Trap MS has been employed to determine the acrylamide content in some Chinese foods. The brominated derivative, 2,3-dibromopropionamide (2,3-DBPA), was found unstable and was converted to 2-bromopropenamide (2-BPA) during the GC/MS analysis. Lowering the injector temperature reduced the formation of 2-BPA. Triethylamine was used to convert 2,3-DBPA to 2-BPA, which was stable during the analysis. The 13 C 3-labeled acrylamide was used as the internal standard. The ratio of peak area of 2-bromopropenamide (m/z 151) to 2-bromopropenamide-13 C 3 (m/z 154) was used for quantification. The recoveries were between 102% and 110% when wheat flour dough was spiked with acrylamide at 10 to 50 μg/kg, with the detection limit of 5 μg/kg. Among the Chinese foods tested (fried gluten, instant noodles, and twisted cruller), old twisted cruller consisted the most acrylamide (890-900 μg/kg), whereas fried gluten yielded the least acrylamide (less than 20 μg/kg), probably due to the absence of starch.
an improved lC/MS/MS method was set up and validated for analyzing acrylamide (aa) in foods inclu... more an improved lC/MS/MS method was set up and validated for analyzing acrylamide (aa) in foods including fried potato snack food, baked breakfast food, bread, coffee and tea drinks which are the most popular stimulant drinks in Taiwan. Two types of cartridge in tandem use, elution volume, and a long column (250 mm), were used to improve the separation of interferences and reduce detection limit. Reproducibility, repeatability, and recovery tests were conducted to assure the analytical method applicable in house validation testing. Participation in the FaPaS ® inter-comparison study resulted in a satisfactory result. The limit of detection was 3 μg/kg; mean recoveries ranged from 95 to 113%; coefficients of variation ranged from 1.3 to 10.0% for repeatability test and 3.3 to 6.9% for reproducibility test. The good results showed the method has been successfully set up to serve as a routinely analytical method. We also found that brown sugar with high aa contents lead to high aa content in some foods including those not cooked at high temperature.
This study explored the feasibility of enhancing cellulose functionalities by using media milling... more This study explored the feasibility of enhancing cellulose functionalities by using media milling to reduce the size of cellulose particles, and assayed various physicochemical and physiological properties of the resulting cellulose. Cellulose has been recognized as dietary fiber by USFDA due to its health benefits. However, its properties like low degradability, stiff texture, and insolubility in water limits its applicability in foods. Milling reduced the volume mean size of cellulose from 25.7 μm to 0.9 μm, which in turn increased the specific surface area (36.78-fold), and swelling capacity (9-fold). Conversely, a reduction in the bulk density (1.41 to 1.32 g/mL) and intrinsic viscosity (165.64 to 77.28 mL/g) were found. The milled cellulose also had significantly enhanced capacity for holding water and binding bile acids and sugars. Moreover, the size reduction also resulted in increased fermentability of cellulose into short chain fatty acids using three human fecal microflora...
ABSTRACTThe functions of three starches (potato, corn, and rice) on the formation of starch and p... more ABSTRACTThe functions of three starches (potato, corn, and rice) on the formation of starch and pork ham batter composite during heating were investigated. Thermal properties were measured by differential scanning calorimetry (DSC) and rheological characteristics were determined by small amplitude oscillatory shearing. DSC thermograms did not show any chemical interactions between starch and meat protein during heating. The dramatic increase in G’ and G” of starch/meat composite appeared to be associated with the gelatinization of starch. The microstructures of pork ham batter, starch, and starch/meat composites were revealed by both scanning electron microscopy and light microscopy.
Acrylamide (AA) contents in 294 snack foods including cereal-based, root- and tuber-based, and se... more Acrylamide (AA) contents in 294 snack foods including cereal-based, root- and tuber-based, and seafood-based foods, nuts, dried beans, and dried fruits purchased in Taiwan were determined by gas chromatography–mass spectrometry in this study. The highest levels of average AA content were found in root- and tuber-based snack foods (435 μg/kg), followed by cereal-based snack foods (299 μg/kg). Rice flour–based, seafood-based, and dried fruit snack foods had the lowest average AA content (<50 μg/kg). This is the first large surveillance of AA content in snack foods in Taiwan. The results could provide important data regarding intake information from the snack foods. In addition, the results showed a great diversity of AA content in snack foods prepared from different ingredients. Rice- and seafood-based products had much lower AA than those made from other ingredients. This information could constitute a good reference for consumers to select products for healthy snacking.
Journal of the American Oil Chemists' Society, 1991
The solubility of cholesterol in supercritical carbon dioxide was determined by a continuous flow... more The solubility of cholesterol in supercritical carbon dioxide was determined by a continuous flow method. The solubility of cholesterol increased with increasing pressure and exhibited retrograde behavior. The Chrastil equation was used to describe the relationship between solubility and the density of carbon dioxide. A model mixture was made by adding cholesterol and fatty acid esters together. Squid visceral oil was esterified as the feed material. Both the model mixture and esterified squid visceral oil were extracted by supercritical carbon dioxide. The experimental results showed that cholesterol could be removed from a model mixture and from esterified squid visceral oil at low pressure (1500 psig) and high temperature (328.2°K). Under these conditions, cholesterol content in the extract was reduced from 2867 mg/100 g to 14.1 mg/100 g.
Journal of the American Oil Chemists' Society, 1991
The solubilities of ethyl palmitate, ethyl oleate, ethyl eicosapentaenoate (EPA) and ethyl docosa... more The solubilities of ethyl palmitate, ethyl oleate, ethyl eicosapentaenoate (EPA) and ethyl docosahexaenoate (DHA) in supercritical carbon dioxide were determined by a continuous flow method. The solubilities of fatty acid ethyl esters increased with pressure and decreased as the temperature was increased. An empirical equation, similar to Chrastil's equation, was used to describe the relationship between solute solubility and the density of carbon dioxide. The empirical equation was further used to qualitatively estimate the separation efficiency of isolating EPA and DHA ethyl esters from fatty acid esters. The operating conditions yielding high solubility gave fast extraction rate but resulted in low separation efficiency. Experiments were conducted to separate ethyl EPA and ethyl DHA from a model mixture containing four fatty acid ethyl esters and from esterified squid visceral oil. The experimental data compared closely with the calculated values.
Several different kinds of extractive distillation agents were investigated to affect the separat... more Several different kinds of extractive distillation agents were investigated to affect the separation of three binary liquid mixtures, isopropyl ether-acetone, methyl acetate-methanol, and isopropyl ethermethyl ethyl ketone. Because of the small size of the extractive distillation column, relative volatilities were assumed constant and the Fenske equation was used to calculate the relative volatilities and the number of minimum theoretical plates. Dimethyl sulfoxide was found to be a good extractive distillation agent. Extractive distillation when employing a proper agent not only negated the azeotropes of the above mixtures, but also improved the efficiency of separation. This process could reverse the relative volatility of isopropyl ether and acetone. This reversion was also found in the system of methyl acetate and methanol when nitrobenzene was the agent. However, normal distillation curves were obtained for the system of isopropyl ether and methyl ethyl ketone undergoing extractive distillation. In the system of methyl acetate and methanol, the relative volatility decreased as the agents' carbon number increased when glycols were used as the agents. In addition, the oxygen number and the locations of hydroxyl groups in the glycols used were believed to affect the values of relative volatility. An appreciable amount of agent must be maintained in the column to affect separation. When dimethyl sulfoxide was an agent for the three systems studied, the relative volatility increased as the addition rate increased. V
ABSTRACTStarches from nine varieties of rice, including four indica, three japonica, and two waxy... more ABSTRACTStarches from nine varieties of rice, including four indica, three japonica, and two waxy cultivars, were used for the investigation of the correlation between retrogradation and water mobility. Retrogradation and water mobility were analyzed by differential scanning calorimetry (DSC) and nuclear magnetic resonance (NMR) and expressed as enthalpy change (ΔH) and differential relaxation rate (ΔR2) for water‐17O. Water contents were measured by DSC and Karl‐Fischer methods. The results indicated that three different profiles, based on amylose content, were observed for the ΔH changes of rice starch cooks during storage. They fit well to the nonlinear regression equations of exponential rise to maximum and exponential growth models. The water content, as measured with DSC, decreased during storage but increased as measured with the Karl‐Fischer method. This discrepancy might be attributed to the different characteristics of water measured by the two methods. The ΔR2 of rice sta...
This study investigated the interrelationship between Lycium barbarum (goji) and gene expression ... more This study investigated the interrelationship between Lycium barbarum (goji) and gene expression in mouse spleen. Oligomicroarray technology was employed to explore the comprehensive response of gene expression and to screen candidate marker genes in the spleens of mice fed a goji suspension. Goji was micronized by media milling and then used to evaluate the effect of size reduction. The average diameter of nano/submicrometer goji was about 100 nm, which exhibited no cytotoxicity to cell lines IEC-6 (rat normal small intestinal cell line) and Caco-2 (human colon adenocarcinoma cell line). It was found that three genes, TNF, Nfkb1, and Bcl-2, were up-regulated and two genes, APAF-1 and caspase-3, were down-regulated by goji. This phenomenon could be helpful for cytoprotection when cells undergo stress or damage that induces the apoptotic pathway. Size reduction into nano/submicrometer scale enhanced bioactivity.
Cellulose is the most common organic compound on Earth. It is not digestible by human and is ofte... more Cellulose is the most common organic compound on Earth. It is not digestible by human and is often referred to as dietary fiber' or 'roughage', acting as a hydrophilic bulking agent for feces. Nevertheless, the pliable but strong characteristics limit the applications of cellulose in food. Size reduction would be an attractive method to broaden the utilization of cellulose. Nano/submicron scale cellulose particles have been prepared by using media mill. The rheological behavior media-milled cellulose-suspension has been investigated using a dynamic rheometer. Cotton cellulose, with a volume mean diameter 33.19 micron, was used as the raw material in this study. The diameter of cellulose was reduced to nano/submicron scale as determined by dynamic laser light measurement and illustrated by TEM. Both concentration and milling time affected the average particle size. In general, increasing milling time reduced the particle size. After being milled for 180 min, the highest c...
GC/Ion-Trap MS has been employed to determine the acrylamide content in some Chinese foods. The b... more GC/Ion-Trap MS has been employed to determine the acrylamide content in some Chinese foods. The brominated derivative, 2,3-dibromopropionamide (2,3-DBPA), was found unstable and was converted to 2-bromopropenamide (2-BPA) during the GC/MS analysis. Lowering the injector temperature reduced the formation of 2-BPA. Triethylamine was used to convert 2,3-DBPA to 2-BPA, which was stable during the analysis. The 13 C 3-labeled acrylamide was used as the internal standard. The ratio of peak area of 2-bromopropenamide (m/z 151) to 2-bromopropenamide-13 C 3 (m/z 154) was used for quantification. The recoveries were between 102% and 110% when wheat flour dough was spiked with acrylamide at 10 to 50 μg/kg, with the detection limit of 5 μg/kg. Among the Chinese foods tested (fried gluten, instant noodles, and twisted cruller), old twisted cruller consisted the most acrylamide (890-900 μg/kg), whereas fried gluten yielded the least acrylamide (less than 20 μg/kg), probably due to the absence of starch.
an improved lC/MS/MS method was set up and validated for analyzing acrylamide (aa) in foods inclu... more an improved lC/MS/MS method was set up and validated for analyzing acrylamide (aa) in foods including fried potato snack food, baked breakfast food, bread, coffee and tea drinks which are the most popular stimulant drinks in Taiwan. Two types of cartridge in tandem use, elution volume, and a long column (250 mm), were used to improve the separation of interferences and reduce detection limit. Reproducibility, repeatability, and recovery tests were conducted to assure the analytical method applicable in house validation testing. Participation in the FaPaS ® inter-comparison study resulted in a satisfactory result. The limit of detection was 3 μg/kg; mean recoveries ranged from 95 to 113%; coefficients of variation ranged from 1.3 to 10.0% for repeatability test and 3.3 to 6.9% for reproducibility test. The good results showed the method has been successfully set up to serve as a routinely analytical method. We also found that brown sugar with high aa contents lead to high aa content in some foods including those not cooked at high temperature.
This study explored the feasibility of enhancing cellulose functionalities by using media milling... more This study explored the feasibility of enhancing cellulose functionalities by using media milling to reduce the size of cellulose particles, and assayed various physicochemical and physiological properties of the resulting cellulose. Cellulose has been recognized as dietary fiber by USFDA due to its health benefits. However, its properties like low degradability, stiff texture, and insolubility in water limits its applicability in foods. Milling reduced the volume mean size of cellulose from 25.7 μm to 0.9 μm, which in turn increased the specific surface area (36.78-fold), and swelling capacity (9-fold). Conversely, a reduction in the bulk density (1.41 to 1.32 g/mL) and intrinsic viscosity (165.64 to 77.28 mL/g) were found. The milled cellulose also had significantly enhanced capacity for holding water and binding bile acids and sugars. Moreover, the size reduction also resulted in increased fermentability of cellulose into short chain fatty acids using three human fecal microflora...
ABSTRACTThe functions of three starches (potato, corn, and rice) on the formation of starch and p... more ABSTRACTThe functions of three starches (potato, corn, and rice) on the formation of starch and pork ham batter composite during heating were investigated. Thermal properties were measured by differential scanning calorimetry (DSC) and rheological characteristics were determined by small amplitude oscillatory shearing. DSC thermograms did not show any chemical interactions between starch and meat protein during heating. The dramatic increase in G’ and G” of starch/meat composite appeared to be associated with the gelatinization of starch. The microstructures of pork ham batter, starch, and starch/meat composites were revealed by both scanning electron microscopy and light microscopy.
Acrylamide (AA) contents in 294 snack foods including cereal-based, root- and tuber-based, and se... more Acrylamide (AA) contents in 294 snack foods including cereal-based, root- and tuber-based, and seafood-based foods, nuts, dried beans, and dried fruits purchased in Taiwan were determined by gas chromatography–mass spectrometry in this study. The highest levels of average AA content were found in root- and tuber-based snack foods (435 μg/kg), followed by cereal-based snack foods (299 μg/kg). Rice flour–based, seafood-based, and dried fruit snack foods had the lowest average AA content (<50 μg/kg). This is the first large surveillance of AA content in snack foods in Taiwan. The results could provide important data regarding intake information from the snack foods. In addition, the results showed a great diversity of AA content in snack foods prepared from different ingredients. Rice- and seafood-based products had much lower AA than those made from other ingredients. This information could constitute a good reference for consumers to select products for healthy snacking.
Journal of the American Oil Chemists' Society, 1991
The solubility of cholesterol in supercritical carbon dioxide was determined by a continuous flow... more The solubility of cholesterol in supercritical carbon dioxide was determined by a continuous flow method. The solubility of cholesterol increased with increasing pressure and exhibited retrograde behavior. The Chrastil equation was used to describe the relationship between solubility and the density of carbon dioxide. A model mixture was made by adding cholesterol and fatty acid esters together. Squid visceral oil was esterified as the feed material. Both the model mixture and esterified squid visceral oil were extracted by supercritical carbon dioxide. The experimental results showed that cholesterol could be removed from a model mixture and from esterified squid visceral oil at low pressure (1500 psig) and high temperature (328.2°K). Under these conditions, cholesterol content in the extract was reduced from 2867 mg/100 g to 14.1 mg/100 g.
Journal of the American Oil Chemists' Society, 1991
The solubilities of ethyl palmitate, ethyl oleate, ethyl eicosapentaenoate (EPA) and ethyl docosa... more The solubilities of ethyl palmitate, ethyl oleate, ethyl eicosapentaenoate (EPA) and ethyl docosahexaenoate (DHA) in supercritical carbon dioxide were determined by a continuous flow method. The solubilities of fatty acid ethyl esters increased with pressure and decreased as the temperature was increased. An empirical equation, similar to Chrastil's equation, was used to describe the relationship between solute solubility and the density of carbon dioxide. The empirical equation was further used to qualitatively estimate the separation efficiency of isolating EPA and DHA ethyl esters from fatty acid esters. The operating conditions yielding high solubility gave fast extraction rate but resulted in low separation efficiency. Experiments were conducted to separate ethyl EPA and ethyl DHA from a model mixture containing four fatty acid ethyl esters and from esterified squid visceral oil. The experimental data compared closely with the calculated values.
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