The presence of mycotoxins in corn-based foods available in Argentina was determined in order to ... more The presence of mycotoxins in corn-based foods available in Argentina was determined in order to make a preliminary exposure assessment. Thirty-eight samples [corn meal ('polenta') and corn flakes] of different local brands were analysed for zearalenone, deoxynivalenol and aflatoxins by TLC and fumonisins (FB1, FB2 and FB3) by HPLC. None of the 38 samples contained any detectable amount of aflatoxins (< 2 micrograms/kg), zearalenone (< 50 micrograms/kg) and deoxynivalenol (< 50 micrograms/kg). By contrast fumonisin contamination was found in 95% of the samples. The highest fumonisin levels were found in corn meal: FB1 (range positives: 60-2860 micrograms/kg; mean positive value: 556 micrograms/kg), FB2 (61-1090 micrograms/kg; 232 micrograms/kg) and FB3 (18-1015 micrograms/kg; 150 micrograms/kg). Low levels of fumonisin B1 were detected in 16/17 corn flakes samples (2-38 micrograms/kg). Total fumonisin levels in corn meal were more than 1000 micrograms/kg in 24% (5/21) of the samples. Although it is not the staple food in Argentina, maize consumption is very important, especially among children. A daily fumonisin intake of 11.3 micrograms/kg of body weight was estimated for child consumers (1-5 years old) based on an average consumption of 200 g of corn meal/day. Calculated at an average rate for all children (consumers or not) the intake estimate was 0.9 microgram/kg of body weight.
Aims To minimize fumonisins (FBs) accumulation by Fusarium verticillioides in post-harvest maize,... more Aims To minimize fumonisins (FBs) accumulation by Fusarium verticillioides in post-harvest maize, using flavonoids obtained from citrus residues: naringin (NAR), neohesperidin (NEO), quercetin (QUER), and its mixtures. Methods and Results Response surface methodology with Box-Behnken design was applied in maize at 0.98 and 0.95 aw. The optimal mixture found, composed of 0.40 mmol kg−1 NAR, 0.16 mmol kg−1 NEO and 0.37 mmol kg−1 QUER, reduced the accumulation of FBs B1, B2, and B3 by 88 ± 6%, 90 ± 6% and 85 ± 5%, respectively, when applied to maize at 0.98 aw. The mentioned mixture led to a 54 ± 9% reduction of fumonisin B1 accumulation in maize adjusted to 0.95 aw. These flavonoids applied individually and as a mixture, affected the structure of both the cell wall and the cytoplasm of F. verticillioides. The cell wall lost rigidity and the cells appeared highly deformed, with ruptured plasmalemma and disrupted endomembranes. Conclusions It was possible to diminish the accumulation of...
... of fruits during processing, affecting creep response and storage modulus: degree of tissue t... more ... of fruits during processing, affecting creep response and storage modulus: degree of tissue turgidity, cellulose microfibrils slipping through the amor-phous matrix of ... about the effect of osmotic dehydration and the type of osmotic agent on material properties of apple, the main ...
The concentrations of free fumonisins (FBs) and hydrolysed fumonisins (HFBs) were determined in 7... more The concentrations of free fumonisins (FBs) and hydrolysed fumonisins (HFBs) were determined in 72 maize samples collected in 2017 from five Argentine provinces. The methodology for HFBs analysis consisted of alkaline hydrolysis followed by high performance liquid chromatography with a fluorescence detector (HPLC-FLD). The developed analytical methodology presented percentages of recovery greater than 74%. Limits of detection were 4.5, 13.0 and 12.9 μg/kg for HFB1, HFB2 and HFB3, respectively. Presence of FBs was found in 86% of the samples. In all cases, the concentration of total HFBs (after the hydrolysis treatment) was superior to the free FBs content (HFBs to FBs median ratio of 2.5), which indicates the presence of hidden fumonisins in Argentinean maize. 8% of the traditionally analysed samples exceeded the limit established by the European Commission for FB1 + FB2. When applying alkaline hydrolysis to the samples, 24% of them exceed this limit.
La Facultad de Ciencias Exactas y Naturales es hoy uno de los centros de investigación y enseñanz... more La Facultad de Ciencias Exactas y Naturales es hoy uno de los centros de investigación y enseñanza más destacados del país, como lo demuestran la cantidad y calidad de sus publicaciones y la formación de recursos humanos de primer nivel en las ciencias básicas. Para comprender esta realidad es importante remontarse a sus orígenes, cuando el 16 de Junio de 1865, el rector Juan María Gutiérrez funda en la Universidad de Buenos Aires el ?Departamento de Ciencias Exactas incluidas las naturales?. Desde sus inicios, la contratación de afamadosprofesores de Europa, y posteriormente los concursos para los nuevos profesores, garantizaron la calidad de la enseñanza. La adquisición de modernos gabinetes de Historia Natural y laboratorios de Química y Física, permitieron ya a partir de 1900, la realización de trabajos prácticos integrados a una enseñanza teórica de excelencia.Este libro nos muestra el hilo conductor en cada una de las disciplinas básicas enseñadas en la Facultad, donde a esos profesores europeos, le siguió una legión de docentes pioneros formados en el país. Estos profesores entre los que se destacan figuras señeras de Química, Geología,Botánica, Zoología, Física y Matemática, formaron a través de la dirección de numerosas tesis doctorales, varias generaciones de discípulos. Los diferentes capítulos nos presentan la fuerte vocación de estos maestros, quienes en medio de frecuentes crisis económicas y políticas, han mantenido por décadas el espíritu de excelencia que lograron transmitir a las futuras generaciones. A veces con rupturas y éxodos, otras permaneciendo en condiciones adversas, pero siempre con un entusiasmo y dedicación dignas de encomio.Confiamos que el lector encontrará en las distintas disciplinas que el conocimiento y avance de la ciencia tuvo el sacrificado esfuerzo de los maestros de nuestros maestros, quienes en conjunto forjaron nuestra realidad actual a través de 150 años de historia.Fil: Borches, Carlos. No especifíca;Fil: Fernandez Prini, Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Ramos, Victor Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Aguirre-Urreta, Maria Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Alzamora, Stella Maris. Universidad Nacional de Rio Negro. Centro de Investigaciones y Transferencia de Rio Negro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Rio Negro; ArgentinaFil: Anaya, Daniel. No especifíca;Fil: Burton, Gerardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad de Microanálisis y Métodos Físicos en Química Orgánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Unidad de Microanálisis y Métodos Físicos en Química Orgánica; ArgentinaFil: Jacovkis, Pablo Miguel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Calzetta, Esteban Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Cerne, Silvia Bibiana. No especifíca;Fil: Diaz, Leandro. No especifíca;Fil: Gottifredi, Juan Carlos Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Jacovkis, Pablo Miguel. No especifíca;Fil: Laborde, Miguel Ángel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles; ArgentinaFil: López De Casenave, Javier. No especifíca;Fil: Mudry, Marta Dolores. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de…
Sorghum (Sorghum bicolor (L.) Moench) is an important cereal produced in and exported from Argent... more Sorghum (Sorghum bicolor (L.) Moench) is an important cereal produced in and exported from Argentina. The risk of contamination by mycotoxins is related to the mycoflora associated with the sorghum grain. This paper reports on the identification of internal mycoflora of sorghum grain harvested in Argentina in 1991, 1992 and 1993, years with different total rainfall levels. A mycological survey
... for aflatoxins. The authors questioned the etiology of the outbreak. Ibeh et al. (1994) exami... more ... for aflatoxins. The authors questioned the etiology of the outbreak. Ibeh et al. (1994) examined the relationship between aflatoxin levels in serum of infertile men in comparison with random controls from the community. The subjects ...
A combinedfactorspreservation technology involving blanching and vacuum solutes (sucrose, potassi... more A combinedfactorspreservation technology involving blanching and vacuum solutes (sucrose, potassium sorbate, ascorbic and citric acids, zinc chloride) impregnation was proposed to minimize color changes in minimally processed kiwifruit slices during one month ...
The antifungal activity of isolated flavonoids from Citrus species, such as naringin, hesperidin ... more The antifungal activity of isolated flavonoids from Citrus species, such as naringin, hesperidin and neohesperidin, and enzymatically-modified derivatives of these compounds, was studied on four fungi often found as food contaminants: Aspergillus parasiticus, ...
Food additives & contaminants. Part B, Surveillance, Jan 23, 2017
Forty samples of milk powder purchased in Uruguay were analysed to assess melamine (MEL) levels. ... more Forty samples of milk powder purchased in Uruguay were analysed to assess melamine (MEL) levels. Trichloroacetic acid and acetonitrile were used to extract and precipitate milk proteins previously to clean up of the samples by solid-phase extraction and then were determined by liquid chromatography coupled to ultraviolet detection. The limit of detection (LOD) and limit of quantification (LOQ)of MEL were 0.006 and 0.019 mg kg-1, respectively. Milk was fortified with MEL at three levels, producing average recoveries higher than 83.8%. The values for positive samples ranged from 0.017 to 0.082 mg kg-1. Nine samples were positive. Three of them had concentrations between LOD and LOQ. The mean MEL contamination was 0.028 mg kg-1. Consumption of milk powder containing these levels of MEL does not constitute a health risk for consumers.
... of fruits during processing, affecting creep response and storage modulus: degree of tissue t... more ... of fruits during processing, affecting creep response and storage modulus: degree of tissue turgidity, cellulose microfibrils slipping through the amor-phous matrix of ... about the effect of osmotic dehydration and the type of osmotic agent on material properties of apple, the main ...
The presence of mycotoxins in corn-based foods available in Argentina was determined in order to ... more The presence of mycotoxins in corn-based foods available in Argentina was determined in order to make a preliminary exposure assessment. Thirty-eight samples [corn meal ('polenta') and corn flakes] of different local brands were analysed for zearalenone, deoxynivalenol and aflatoxins by TLC and fumonisins (FB1, FB2 and FB3) by HPLC. None of the 38 samples contained any detectable amount of aflatoxins (< 2 micrograms/kg), zearalenone (< 50 micrograms/kg) and deoxynivalenol (< 50 micrograms/kg). By contrast fumonisin contamination was found in 95% of the samples. The highest fumonisin levels were found in corn meal: FB1 (range positives: 60-2860 micrograms/kg; mean positive value: 556 micrograms/kg), FB2 (61-1090 micrograms/kg; 232 micrograms/kg) and FB3 (18-1015 micrograms/kg; 150 micrograms/kg). Low levels of fumonisin B1 were detected in 16/17 corn flakes samples (2-38 micrograms/kg). Total fumonisin levels in corn meal were more than 1000 micrograms/kg in 24% (5/21) of the samples. Although it is not the staple food in Argentina, maize consumption is very important, especially among children. A daily fumonisin intake of 11.3 micrograms/kg of body weight was estimated for child consumers (1-5 years old) based on an average consumption of 200 g of corn meal/day. Calculated at an average rate for all children (consumers or not) the intake estimate was 0.9 microgram/kg of body weight.
Aims To minimize fumonisins (FBs) accumulation by Fusarium verticillioides in post-harvest maize,... more Aims To minimize fumonisins (FBs) accumulation by Fusarium verticillioides in post-harvest maize, using flavonoids obtained from citrus residues: naringin (NAR), neohesperidin (NEO), quercetin (QUER), and its mixtures. Methods and Results Response surface methodology with Box-Behnken design was applied in maize at 0.98 and 0.95 aw. The optimal mixture found, composed of 0.40 mmol kg−1 NAR, 0.16 mmol kg−1 NEO and 0.37 mmol kg−1 QUER, reduced the accumulation of FBs B1, B2, and B3 by 88 ± 6%, 90 ± 6% and 85 ± 5%, respectively, when applied to maize at 0.98 aw. The mentioned mixture led to a 54 ± 9% reduction of fumonisin B1 accumulation in maize adjusted to 0.95 aw. These flavonoids applied individually and as a mixture, affected the structure of both the cell wall and the cytoplasm of F. verticillioides. The cell wall lost rigidity and the cells appeared highly deformed, with ruptured plasmalemma and disrupted endomembranes. Conclusions It was possible to diminish the accumulation of...
... of fruits during processing, affecting creep response and storage modulus: degree of tissue t... more ... of fruits during processing, affecting creep response and storage modulus: degree of tissue turgidity, cellulose microfibrils slipping through the amor-phous matrix of ... about the effect of osmotic dehydration and the type of osmotic agent on material properties of apple, the main ...
The concentrations of free fumonisins (FBs) and hydrolysed fumonisins (HFBs) were determined in 7... more The concentrations of free fumonisins (FBs) and hydrolysed fumonisins (HFBs) were determined in 72 maize samples collected in 2017 from five Argentine provinces. The methodology for HFBs analysis consisted of alkaline hydrolysis followed by high performance liquid chromatography with a fluorescence detector (HPLC-FLD). The developed analytical methodology presented percentages of recovery greater than 74%. Limits of detection were 4.5, 13.0 and 12.9 μg/kg for HFB1, HFB2 and HFB3, respectively. Presence of FBs was found in 86% of the samples. In all cases, the concentration of total HFBs (after the hydrolysis treatment) was superior to the free FBs content (HFBs to FBs median ratio of 2.5), which indicates the presence of hidden fumonisins in Argentinean maize. 8% of the traditionally analysed samples exceeded the limit established by the European Commission for FB1 + FB2. When applying alkaline hydrolysis to the samples, 24% of them exceed this limit.
La Facultad de Ciencias Exactas y Naturales es hoy uno de los centros de investigación y enseñanz... more La Facultad de Ciencias Exactas y Naturales es hoy uno de los centros de investigación y enseñanza más destacados del país, como lo demuestran la cantidad y calidad de sus publicaciones y la formación de recursos humanos de primer nivel en las ciencias básicas. Para comprender esta realidad es importante remontarse a sus orígenes, cuando el 16 de Junio de 1865, el rector Juan María Gutiérrez funda en la Universidad de Buenos Aires el ?Departamento de Ciencias Exactas incluidas las naturales?. Desde sus inicios, la contratación de afamadosprofesores de Europa, y posteriormente los concursos para los nuevos profesores, garantizaron la calidad de la enseñanza. La adquisición de modernos gabinetes de Historia Natural y laboratorios de Química y Física, permitieron ya a partir de 1900, la realización de trabajos prácticos integrados a una enseñanza teórica de excelencia.Este libro nos muestra el hilo conductor en cada una de las disciplinas básicas enseñadas en la Facultad, donde a esos profesores europeos, le siguió una legión de docentes pioneros formados en el país. Estos profesores entre los que se destacan figuras señeras de Química, Geología,Botánica, Zoología, Física y Matemática, formaron a través de la dirección de numerosas tesis doctorales, varias generaciones de discípulos. Los diferentes capítulos nos presentan la fuerte vocación de estos maestros, quienes en medio de frecuentes crisis económicas y políticas, han mantenido por décadas el espíritu de excelencia que lograron transmitir a las futuras generaciones. A veces con rupturas y éxodos, otras permaneciendo en condiciones adversas, pero siempre con un entusiasmo y dedicación dignas de encomio.Confiamos que el lector encontrará en las distintas disciplinas que el conocimiento y avance de la ciencia tuvo el sacrificado esfuerzo de los maestros de nuestros maestros, quienes en conjunto forjaron nuestra realidad actual a través de 150 años de historia.Fil: Borches, Carlos. No especifíca;Fil: Fernandez Prini, Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Ramos, Victor Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Aguirre-Urreta, Maria Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Alzamora, Stella Maris. Universidad Nacional de Rio Negro. Centro de Investigaciones y Transferencia de Rio Negro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Rio Negro; ArgentinaFil: Anaya, Daniel. No especifíca;Fil: Burton, Gerardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad de Microanálisis y Métodos Físicos en Química Orgánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Unidad de Microanálisis y Métodos Físicos en Química Orgánica; ArgentinaFil: Jacovkis, Pablo Miguel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Calzetta, Esteban Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Cerne, Silvia Bibiana. No especifíca;Fil: Diaz, Leandro. No especifíca;Fil: Gottifredi, Juan Carlos Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Jacovkis, Pablo Miguel. No especifíca;Fil: Laborde, Miguel Ángel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles; ArgentinaFil: López De Casenave, Javier. No especifíca;Fil: Mudry, Marta Dolores. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de…
Sorghum (Sorghum bicolor (L.) Moench) is an important cereal produced in and exported from Argent... more Sorghum (Sorghum bicolor (L.) Moench) is an important cereal produced in and exported from Argentina. The risk of contamination by mycotoxins is related to the mycoflora associated with the sorghum grain. This paper reports on the identification of internal mycoflora of sorghum grain harvested in Argentina in 1991, 1992 and 1993, years with different total rainfall levels. A mycological survey
... for aflatoxins. The authors questioned the etiology of the outbreak. Ibeh et al. (1994) exami... more ... for aflatoxins. The authors questioned the etiology of the outbreak. Ibeh et al. (1994) examined the relationship between aflatoxin levels in serum of infertile men in comparison with random controls from the community. The subjects ...
A combinedfactorspreservation technology involving blanching and vacuum solutes (sucrose, potassi... more A combinedfactorspreservation technology involving blanching and vacuum solutes (sucrose, potassium sorbate, ascorbic and citric acids, zinc chloride) impregnation was proposed to minimize color changes in minimally processed kiwifruit slices during one month ...
The antifungal activity of isolated flavonoids from Citrus species, such as naringin, hesperidin ... more The antifungal activity of isolated flavonoids from Citrus species, such as naringin, hesperidin and neohesperidin, and enzymatically-modified derivatives of these compounds, was studied on four fungi often found as food contaminants: Aspergillus parasiticus, ...
Food additives & contaminants. Part B, Surveillance, Jan 23, 2017
Forty samples of milk powder purchased in Uruguay were analysed to assess melamine (MEL) levels. ... more Forty samples of milk powder purchased in Uruguay were analysed to assess melamine (MEL) levels. Trichloroacetic acid and acetonitrile were used to extract and precipitate milk proteins previously to clean up of the samples by solid-phase extraction and then were determined by liquid chromatography coupled to ultraviolet detection. The limit of detection (LOD) and limit of quantification (LOQ)of MEL were 0.006 and 0.019 mg kg-1, respectively. Milk was fortified with MEL at three levels, producing average recoveries higher than 83.8%. The values for positive samples ranged from 0.017 to 0.082 mg kg-1. Nine samples were positive. Three of them had concentrations between LOD and LOQ. The mean MEL contamination was 0.028 mg kg-1. Consumption of milk powder containing these levels of MEL does not constitute a health risk for consumers.
... of fruits during processing, affecting creep response and storage modulus: degree of tissue t... more ... of fruits during processing, affecting creep response and storage modulus: degree of tissue turgidity, cellulose microfibrils slipping through the amor-phous matrix of ... about the effect of osmotic dehydration and the type of osmotic agent on material properties of apple, the main ...
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