[Objective] The aim was to evaluate the uncertainty of determining aspartame in beverage by high performance liquid chromatography （ HPLC）. [Method] The content of aspartame in beverage was determined by HPLC, then ...[Objective] The aim was to evaluate the uncertainty of determining aspartame in beverage by high performance liquid chromatography （ HPLC）. [Method] The content of aspartame in beverage was determined by HPLC, then the source of uncertainty in the whole determination process was analyzed, and each component of uncertainty was evaluated and combined. [ Result] Through 6 repeated determinations by the method in GB/T 22254-2008 ＂Determination of Aspartame in Food＂, the average content of aspartame in beverage was （0.806 ±0.038） g/kg, and k =2. The main sources of uncertainty to affect the process were the sample weighting process, the preparation process of standard solution introduced by sample constant volume and the uncertainty introduced by fitting standard curve. ①The uncertainty of standard work-solution. The combined uncertainty of standard work-solution was 0.013 9, among them the uncertainty introduced by standard sample purity was 0.005 8, the standard uncertainty introduced by standard material weighting was 1.49 ×10^4, the relative uncertainty introduced by glass apparatus calibration in the preparation process of aspartame standard reserving solution was 0. 007 88, and the uncertainty introduced by glass apparatus calibration in the preparation process of standard work-solution was 0. 009 9. ②The uncertainty introduced by the preparation process of sample specimen. Among them the relative standard uncertainty introduced by sample weighting process was 0. 009, and the uncertainty introduced by sample constant volume was 0.000 78. ③The uncertainty introduced by the fitting process of standard curve. Among them the relative uncertainty of curve fitting was 0.002 46, the uncertainty introduced by the determined results of aspartame was 0.017 0, the total combined standard uncertainty was 0.023 9, and the expanded standard uncertainty was 0.019. [ Conclusion] The uncertainty components of standard solution, standard curve and repeatability are the main sources of uncertainty, while those of sample weighting and sample constant volume account for little proportion.展开更多
Aspartame, a ＂first generation sweetener＂, is widely used in a variety of foods, beverages, and medicine. The FDA has determined the acceptable daily intake （ADI） value of aspartame to be 50 mg/kg, day, while the ...Aspartame, a ＂first generation sweetener＂, is widely used in a variety of foods, beverages, and medicine. The FDA has determined the acceptable daily intake （ADI） value of aspartame to be 50 mg/kg, day, while the JECFA （Joint FAO/WHO Expert Committee on Food Additives） has set this value at 40 mg/kg of body weight/day. Safety issues have been raised about aspartame due to its metabolites, specifically toxicity from methanol and/or its systemic metabolites formaldehyde and formic acid. The immune system is now recognized as a target organ for many xenobiotics, such as drugs and chemicals, which are able to trigger unwanted apoptosis or to alter the regulation of apoptosis. Our previous studies has shown that oral administration of aspartame [40 mg/（kg, day）] or its metabolites for 90 days increased oxidative stress in immune organs of Wistar albino rats. In this present study, we aimed to clarify whether aspartame consumption over a longer period （90-days） has any effect on the expression ofhsp70, bcl- 2 and bax at both mRNA transcript and protein expression levels in immune organs. We observed that oral administration of aspartame for 90 days did not cause any apparent DNA fragmentation in immune organs of aspartame treated animals; however, there was a significant increase in hsp70 expression, apart from significant alteration in bcl-2 and bax at both mRNA transcript and protein expression level in the immune organs of aspartame treated animals compared to controls. Hence, the results indicated that hsp70 levels increased in response to oxidative injury induced by aspartame metabolites; however, these metabolites did not induce apoptosis in the immune organs. Furthermore, detailed analyses are needed to elucidate the precise molecular mechanisms involved in these changes.展开更多
Three thermal analytical techniques such as differential scanning calorimetry(DSC), thermal gravimetric analysis(TGA) using five heating rates, and DSC-Fourier Transform Infrared(DSCFTIR) microspectroscopy using one h...Three thermal analytical techniques such as differential scanning calorimetry(DSC), thermal gravimetric analysis(TGA) using five heating rates, and DSC-Fourier Transform Infrared(DSCFTIR) microspectroscopy using one heating rate, were used to determine the thermal characteristics and the dehydration process of aspartame(APM) hemihydrate in the solid state.The intramolecular cyclization process of APM anhydrate was also examined. One exothermic and four endothermic peaks were observed in the DSC thermogram of APM hemihydrate,in which the exothermic peak was due to the crystallization of some amorphous APM caused by dehydration process from hemihydrate to anhydride. While four endothermic peaks were corresponded to the evaporation of absorbed water, the dehydration of hemihydrate, the diketopiperazines(DKP) formation via intramolecular cyclization, and the melting of DKP, respectively. The weight loss measured in TGA curve of APM hemihydrate was associated with these endothermic peaks in the DSC thermogram. According to the Flynn–Wall–Ozawa(FWO)model, the activation energy of dehydration process within 100–150 °C was about 218 ± 11 kJ/mol determined by TGA technique. Both the dehydration and DKP formation processes for solid-state APM hemihydrate were markedly evidenced from the thermal-responsive changes in several specific FTIR bands by a single-step DSC-FTIR microspectroscopy.展开更多
Aspartame (APM) or L-aspartyl-L-phenylalanine methyl ester, a common artificial non-saccharide sweetener used as a sugar substitute in many foods and beverages, has shown some side effects on consumers. The objective ...Aspartame (APM) or L-aspartyl-L-phenylalanine methyl ester, a common artificial non-saccharide sweetener used as a sugar substitute in many foods and beverages, has shown some side effects on consumers. The objective of the present study is to study the acute impact of various doses of daily ingestion of APM on blood parameters of mice. Sixty healthy 3 months old male mice raised in the departmental animal house were divided into five groups i.e. the control were fed normal diet and tap water, while other 4 groups (12 each) were daily orally fed with 1 mL of either 40, 500, 1000 or 1500 mg/Kg b wt, dissolved in distilled water using gavages for consecutive 5 weeks. Fresh blood samples collected directly from the heart at dissection were subjected to complete blood counting (CBC) using automated blood analyzer (Cell DYN-1700) in addition to manual differential Leucocytes (WBC) counting. There has been a significant increase (p ≤ 0.01) in WBC counts starting from the lowest dose (40 mg/Kg·b·wt);significant decrease (p ≤ 0.01) in both Hemoglobin percentages (Hb%) and in Lymphocyte percentages (p ≤ 0.004) in comparison with control. It is concluded that the ingestion of aspartame using the above doses has acute impact and is not dose-dependent on blood parameters which could exert further, on the long run, health risks on to other tissues of consumers.展开更多
Objective: To identify the effects of the consumption of non-nutritive sweeteners on memory retention and on the histology of the hippocampus.Methods: In this study, 20 mice were used to determine if there is an effec...Objective: To identify the effects of the consumption of non-nutritive sweeteners on memory retention and on the histology of the hippocampus.Methods: In this study, 20 mice were used to determine if there is an effect of consuming the maximum allowable dose of the non-nutritive sweeteners on the memory retention and on the histology of the hippocampus. The mice were distributed into four groups and the treatments were given via oral gavage: Group 1(water), Group 2(aspartame: 1 000 mg/kg), Group 3(stevia: 1 000 mg/kg) and Group 4(sucralose:16 000 mg/kg). Treatments were administered to the different experimental groups for 32 days, after which memory retention was tested using the two-day water maze protocol.After the tests, the mice were sacrificed and the brain was analyzed histologically for neurotrophic effects.Results: Based on the results of the two-day water maze protocol, there were no differences between the non-nutritive sweeteners and the control group. However, stevia showed high cellular apoptosis followed by aspartame, sucralose and control group.Conclusions: There was no significant effect on the memory of the mice. It showed histologically however, that stevia had a significant neurotropic effect compared to the other sweeteners.展开更多
The present study was carried out to investigate the acute effect of aspartame on oxidative stress in the Wistar albino rat brain. We sought to investigate whether acute administration of aspartame （75 mg/kg） could ...The present study was carried out to investigate the acute effect of aspartame on oxidative stress in the Wistar albino rat brain. We sought to investigate whether acute administration of aspartame （75 mg/kg） could release methanol and induce oxidative stress in the rat brain 24 hours after administration. To mimic human methanol metabolism, methotrexate treated rats were used to study aspartame effects. Wistar strain male albino rats were administered with aspartame orally as a single dose and studied along with controls and methotrexate treated controls. Blood methanol and formate level were estimated after 24 hours and rats were sacrificed and free radical changes were observed in discrete regions by assessing the scavenging enzymes, reduce dglutathione （GSH）, lipid peroxidation and protein thiol levels. There was a significant increase in lipid peroxidation levels, superoxide dismutase activity （SOD）, glutathione peroxidase levels （GPx）, and catalase activity （CAT） with a significant decrease in GSH and protein thiol. Aspartame exposure resulted in detectable methanol even after 24 hours. Methanol and its metabolites may be responsible for the generation of oxidative stress in brain regions. The observed alteration in aspartame fed animals may be due to its metabolite methanol and elevated formate. The elevated free radicals due to methanol induced oxidative stress.展开更多
A non-saccharide artificial sweetener, aspartame (L-aspartyl-L-phenylalanine methyl ester) is used worldwide as a sugar substitute in many foods and beverages. The objective of this work was to clarify the acute impac...A non-saccharide artificial sweetener, aspartame (L-aspartyl-L-phenylalanine methyl ester) is used worldwide as a sugar substitute in many foods and beverages. The objective of this work was to clarify the acute impact of various doses of daily ingestion of Aspartame at the cellular level of the liver tissues in mice. Sixty adult male mice were divided into five groups including control fed normal diet and tap water, while other 4 groups (12 each) were daily fed orally with 1 mL of either 40, 500, 1000 and 1500 mg/Kg b.wt. APM dissolved in distilled water using gavages for consecutive 5 weeks. Liver samples fixed in 10% formalin were cut as 5 μm using Leica microtome and the sections were stained with both routine Heamatoxylene and Eosin (H & E) as well as Transmission electron Microscope (TEM). Histological results showed cellular changes in the hepatic tissues which were proportional with the increased doses. The hepatocytes had developed fatty droplets in the cytoplasm of almost all cells, loss of nuclei, necrosis detectable at LM level. Lymphatic nodules were also generated around the triads and the central hepatic veins as well as intracellular gaps with higher doses. The TEM results demonstrated degradation of mitochondria indicating the direct acute effects of the aspartame on hepatic tissues which all were proportional with the increased doses. It is concluded that the daily ingestion of aspartame, even at lower doses, has acute effects and is dose dependant on hepatic cells which could exert further risks onto other tissues of consumers on the long run.展开更多
[Objectives]This study was conducted to establish a method for the determination of aspartame in liquor by high performance liquid chromatography.[Methods]The liquor samples having volumes fixed with ultrapure water w...[Objectives]This study was conducted to establish a method for the determination of aspartame in liquor by high performance liquid chromatography.[Methods]The liquor samples having volumes fixed with ultrapure water were filtered by 0.22μm water phase,and then the content of aspartame in liquor was determined by high performance liquid chromatography using methanol(A)and ultrapure water(B)as mobile phase for isocratic elution.[Results]The results showed that a good linearity was obtained for the standard curve(R^(2)=99.98%)in the method,and its quantitative limit was 5.34 mg/kg.Its recovery was 91.26%,91.92%,and 90.55%,respectively.[Conclusions]The method has high sensitivity,high recovery and low quantitative limit,and it was a suitable method for the determination of aspartame in liquor.展开更多
基金Supported by the Key Project of Science and Technology of Anhui Province(08010302216)~~
文摘[Objective] The aim was to evaluate the uncertainty of determining aspartame in beverage by high performance liquid chromatography （ HPLC）. [Method] The content of aspartame in beverage was determined by HPLC, then the source of uncertainty in the whole determination process was analyzed, and each component of uncertainty was evaluated and combined. [ Result] Through 6 repeated determinations by the method in GB/T 22254-2008 ＂Determination of Aspartame in Food＂, the average content of aspartame in beverage was （0.806 ±0.038） g/kg, and k =2. The main sources of uncertainty to affect the process were the sample weighting process, the preparation process of standard solution introduced by sample constant volume and the uncertainty introduced by fitting standard curve. ①The uncertainty of standard work-solution. The combined uncertainty of standard work-solution was 0.013 9, among them the uncertainty introduced by standard sample purity was 0.005 8, the standard uncertainty introduced by standard material weighting was 1.49 ×10^4, the relative uncertainty introduced by glass apparatus calibration in the preparation process of aspartame standard reserving solution was 0. 007 88, and the uncertainty introduced by glass apparatus calibration in the preparation process of standard work-solution was 0. 009 9. ②The uncertainty introduced by the preparation process of sample specimen. Among them the relative standard uncertainty introduced by sample weighting process was 0. 009, and the uncertainty introduced by sample constant volume was 0.000 78. ③The uncertainty introduced by the fitting process of standard curve. Among them the relative uncertainty of curve fitting was 0.002 46, the uncertainty introduced by the determined results of aspartame was 0.017 0, the total combined standard uncertainty was 0.023 9, and the expanded standard uncertainty was 0.019. [ Conclusion] The uncertainty components of standard solution, standard curve and repeatability are the main sources of uncertainty, while those of sample weighting and sample constant volume account for little proportion.
基金the University of Madras for their financial support.[UGC No.D.1.(C)/TE/2012/1868
文摘Aspartame, a ＂first generation sweetener＂, is widely used in a variety of foods, beverages, and medicine. The FDA has determined the acceptable daily intake （ADI） value of aspartame to be 50 mg/kg, day, while the JECFA （Joint FAO/WHO Expert Committee on Food Additives） has set this value at 40 mg/kg of body weight/day. Safety issues have been raised about aspartame due to its metabolites, specifically toxicity from methanol and/or its systemic metabolites formaldehyde and formic acid. The immune system is now recognized as a target organ for many xenobiotics, such as drugs and chemicals, which are able to trigger unwanted apoptosis or to alter the regulation of apoptosis. Our previous studies has shown that oral administration of aspartame [40 mg/（kg, day）] or its metabolites for 90 days increased oxidative stress in immune organs of Wistar albino rats. In this present study, we aimed to clarify whether aspartame consumption over a longer period （90-days） has any effect on the expression ofhsp70, bcl- 2 and bax at both mRNA transcript and protein expression levels in immune organs. We observed that oral administration of aspartame for 90 days did not cause any apparent DNA fragmentation in immune organs of aspartame treated animals; however, there was a significant increase in hsp70 expression, apart from significant alteration in bcl-2 and bax at both mRNA transcript and protein expression level in the immune organs of aspartame treated animals compared to controls. Hence, the results indicated that hsp70 levels increased in response to oxidative injury induced by aspartame metabolites; however, these metabolites did not induce apoptosis in the immune organs. Furthermore, detailed analyses are needed to elucidate the precise molecular mechanisms involved in these changes.
文摘Three thermal analytical techniques such as differential scanning calorimetry(DSC), thermal gravimetric analysis(TGA) using five heating rates, and DSC-Fourier Transform Infrared(DSCFTIR) microspectroscopy using one heating rate, were used to determine the thermal characteristics and the dehydration process of aspartame(APM) hemihydrate in the solid state.The intramolecular cyclization process of APM anhydrate was also examined. One exothermic and four endothermic peaks were observed in the DSC thermogram of APM hemihydrate,in which the exothermic peak was due to the crystallization of some amorphous APM caused by dehydration process from hemihydrate to anhydride. While four endothermic peaks were corresponded to the evaporation of absorbed water, the dehydration of hemihydrate, the diketopiperazines(DKP) formation via intramolecular cyclization, and the melting of DKP, respectively. The weight loss measured in TGA curve of APM hemihydrate was associated with these endothermic peaks in the DSC thermogram. According to the Flynn–Wall–Ozawa(FWO)model, the activation energy of dehydration process within 100–150 °C was about 218 ± 11 kJ/mol determined by TGA technique. Both the dehydration and DKP formation processes for solid-state APM hemihydrate were markedly evidenced from the thermal-responsive changes in several specific FTIR bands by a single-step DSC-FTIR microspectroscopy.
文摘Aspartame (APM) or L-aspartyl-L-phenylalanine methyl ester, a common artificial non-saccharide sweetener used as a sugar substitute in many foods and beverages, has shown some side effects on consumers. The objective of the present study is to study the acute impact of various doses of daily ingestion of APM on blood parameters of mice. Sixty healthy 3 months old male mice raised in the departmental animal house were divided into five groups i.e. the control were fed normal diet and tap water, while other 4 groups (12 each) were daily orally fed with 1 mL of either 40, 500, 1000 or 1500 mg/Kg b wt, dissolved in distilled water using gavages for consecutive 5 weeks. Fresh blood samples collected directly from the heart at dissection were subjected to complete blood counting (CBC) using automated blood analyzer (Cell DYN-1700) in addition to manual differential Leucocytes (WBC) counting. There has been a significant increase (p ≤ 0.01) in WBC counts starting from the lowest dose (40 mg/Kg·b·wt);significant decrease (p ≤ 0.01) in both Hemoglobin percentages (Hb%) and in Lymphocyte percentages (p ≤ 0.004) in comparison with control. It is concluded that the ingestion of aspartame using the above doses has acute impact and is not dose-dependent on blood parameters which could exert further, on the long run, health risks on to other tissues of consumers.
文摘Objective: To identify the effects of the consumption of non-nutritive sweeteners on memory retention and on the histology of the hippocampus.Methods: In this study, 20 mice were used to determine if there is an effect of consuming the maximum allowable dose of the non-nutritive sweeteners on the memory retention and on the histology of the hippocampus. The mice were distributed into four groups and the treatments were given via oral gavage: Group 1(water), Group 2(aspartame: 1 000 mg/kg), Group 3(stevia: 1 000 mg/kg) and Group 4(sucralose:16 000 mg/kg). Treatments were administered to the different experimental groups for 32 days, after which memory retention was tested using the two-day water maze protocol.After the tests, the mice were sacrificed and the brain was analyzed histologically for neurotrophic effects.Results: Based on the results of the two-day water maze protocol, there were no differences between the non-nutritive sweeteners and the control group. However, stevia showed high cellular apoptosis followed by aspartame, sucralose and control group.Conclusions: There was no significant effect on the memory of the mice. It showed histologically however, that stevia had a significant neurotropic effect compared to the other sweeteners.
基金financial assistance was provided by the University of Madras
文摘The present study was carried out to investigate the acute effect of aspartame on oxidative stress in the Wistar albino rat brain. We sought to investigate whether acute administration of aspartame （75 mg/kg） could release methanol and induce oxidative stress in the rat brain 24 hours after administration. To mimic human methanol metabolism, methotrexate treated rats were used to study aspartame effects. Wistar strain male albino rats were administered with aspartame orally as a single dose and studied along with controls and methotrexate treated controls. Blood methanol and formate level were estimated after 24 hours and rats were sacrificed and free radical changes were observed in discrete regions by assessing the scavenging enzymes, reduce dglutathione （GSH）, lipid peroxidation and protein thiol levels. There was a significant increase in lipid peroxidation levels, superoxide dismutase activity （SOD）, glutathione peroxidase levels （GPx）, and catalase activity （CAT） with a significant decrease in GSH and protein thiol. Aspartame exposure resulted in detectable methanol even after 24 hours. Methanol and its metabolites may be responsible for the generation of oxidative stress in brain regions. The observed alteration in aspartame fed animals may be due to its metabolite methanol and elevated formate. The elevated free radicals due to methanol induced oxidative stress.
文摘A non-saccharide artificial sweetener, aspartame (L-aspartyl-L-phenylalanine methyl ester) is used worldwide as a sugar substitute in many foods and beverages. The objective of this work was to clarify the acute impact of various doses of daily ingestion of Aspartame at the cellular level of the liver tissues in mice. Sixty adult male mice were divided into five groups including control fed normal diet and tap water, while other 4 groups (12 each) were daily fed orally with 1 mL of either 40, 500, 1000 and 1500 mg/Kg b.wt. APM dissolved in distilled water using gavages for consecutive 5 weeks. Liver samples fixed in 10% formalin were cut as 5 μm using Leica microtome and the sections were stained with both routine Heamatoxylene and Eosin (H & E) as well as Transmission electron Microscope (TEM). Histological results showed cellular changes in the hepatic tissues which were proportional with the increased doses. The hepatocytes had developed fatty droplets in the cytoplasm of almost all cells, loss of nuclei, necrosis detectable at LM level. Lymphatic nodules were also generated around the triads and the central hepatic veins as well as intracellular gaps with higher doses. The TEM results demonstrated degradation of mitochondria indicating the direct acute effects of the aspartame on hepatic tissues which all were proportional with the increased doses. It is concluded that the daily ingestion of aspartame, even at lower doses, has acute effects and is dose dependant on hepatic cells which could exert further risks onto other tissues of consumers on the long run.
文摘[Objectives]This study was conducted to establish a method for the determination of aspartame in liquor by high performance liquid chromatography.[Methods]The liquor samples having volumes fixed with ultrapure water were filtered by 0.22μm water phase,and then the content of aspartame in liquor was determined by high performance liquid chromatography using methanol(A)and ultrapure water(B)as mobile phase for isocratic elution.[Results]The results showed that a good linearity was obtained for the standard curve(R^(2)=99.98%)in the method,and its quantitative limit was 5.34 mg/kg.Its recovery was 91.26%,91.92%,and 90.55%,respectively.[Conclusions]The method has high sensitivity,high recovery and low quantitative limit,and it was a suitable method for the determination of aspartame in liquor.
