O objetivo deste trabalho foi determinar o efeito de extratos naturais vegetais na germinacao, cr... more O objetivo deste trabalho foi determinar o efeito de extratos naturais vegetais na germinacao, crescimento vegetativo e resistencia termica de esporos de Desulfotomaculum nigrificans, um microrganismo contaminante de acucar e vegetais. A metodologia descrita por Donnelly e Busta (1980) foi utilizada para preparar e ativar 40min/97oC) um lote de esporos de D.nigrificans em Caldo Soytone (CS) e Caldo de Cana (CC), A contagem dos esporas foi realizada em Sulfite Agar em tubos de rosca, ou em Caldo Tioglicalato Fluido com neutralizante pelo metodo do NMP-3; em tubos exaustados, se lados com vaspar e incubados a 55 °C. Dos 29 extratos naturais vegetais ensaiados contra 102esporos/ml, gengibre, angelica, alecrim e eucalipto (EFE) inibiram o crescimento vegetativo a concentracoes de 0,01%v/v ou maiores, e extrato de sementes citricas (ESC) inibiu o crescimento vegetativa a concentracoes de 0,001%v/v ou maiores. Quando a concentracao de esporos de D. nigrificans foi de 105/ml, CSE e EFE mostraram os melhores resultados: 0,1 e l%v/v, respectivamente inibiram o crescimento vegetativa. Somente ESC a 0,001 e 0,0001 %v/v, e EFE a 0,1 e 1 %v/v foram ensaiados na germinacao dos esporos de D.nigrificans em CS e CC pelo metodo da perda da resistencia termica; nas concentracoes ensaiadas nenhum destes extratos demonstraram efeito inibidor sobre a germinacao nestes meios. O efeito de tratamentos termo-quimicos na resistencia dos esporos de D. nigrificans foi avaliado pela adicao de ESC a concentracao de 0,05%v/v em CS (pH 7,6) e CC (pH 5,15) usando a metodo do tubo TDT. ESC diminuiu a resistencia termica dos esporos de D. nigrificans em aproximadamente 5%, 25% e 30%, respectivamente para tratamentos termicos a 115, 120 e 125°C, usando tanto CS como CC. Os valores de D(min) obtidos em CS foram maiores que aqueles obtidos em CC, provavelmente devido ao baixo pH do CC. Os valores de Z(°C) obtidos sao equivalentes aos observados na literatura (8-10°C) para este microrganismo Abstract
Particles may be formed from mixtures of polysaccharides and proteins based on the interaction be... more Particles may be formed from mixtures of polysaccharides and proteins based on the interaction between these biopolymers. They can carry lipophilic bioactive compounds protecting them against gastric conditions and controlling the release of these molecules. This study aimed to produce particles of pectin and alginate coated by electrostatic interaction using isolated soy protein (ISP). These particles were evaluated for their stability by in vitro simulation of gastrointestinal conditions, pH changes and different concentrations of NaCl. The use of an ISP solution at 8% protein concentration resulted in microparticles with high protein content adsorbed (47.61%). The stability test showed that high concentrations of NaCl and low pH destabilized the protein layer with subsequent release to the environment, however, the particles remained intact. The particles coated with isolated soy protein (ISPPart) were resistant to gastric conditions, but were disintegrated in the intestinal envi...
The rheological behaviour of mume pulp at 6, 7, 8 and 9 °Brix was investigated using a rotational... more The rheological behaviour of mume pulp at 6, 7, 8 and 9 °Brix was investigated using a rotational viscometer at temperatures ranging from 15 to 75 °C. The rheological models of Herschel-Bulkley and Ostwald-Waele (Power Law) were fitted to obtain the rheological parameters of the mume pulp. The product was described as time non-dependent and presented a viscosity of 1.9 Pa.s at 15 °C and 1.1°Pa.s at 65 and 75 °C for the 9 °Brix pulp. The pulp showed non-Newtonian behaviour and the Herschel-Bulkley model was used to describe this behaviour. The activation energy ranged from 6.6-10.6 kJ.mol-1 and the consistency index from 18.0-22.9 Pa.s n for the 9 °Brix pulp and 8.3-12.2 Pa.s n for the 8 °Brix pulp at temperatures varying from 15 to 75 °C. The models presented high correlation values for all the rheological data obtained in the present work.O comportamento reológico de polpa de umê, com 6, 7, 8 e 9 °Brix, foi avaliado utilizando-se um viscosímetro rotacional nas temperaturas de 15 a ...
Various researchers have studied the importance of the oral transmission of Chagas' disease s... more Various researchers have studied the importance of the oral transmission of Chagas' disease since the mid-20th century. Only in recent years, due to an outbreak that occurred in the Brazilian State of Santa Catarina in 2005 and to various outbreaks occurring during the last 3 years in the Brazilian Amazon basin, mainly associated with the consumption of Amazonian palm berry or açaí (Euterpe oleracea Mart.) juice, has this transmission route aroused the attention of researchers. Nevertheless, reports published in the 1960s already indicated the possibility of Chagas' disease transmission via food in Brazil, mainly in the Amazonian region. Recently, in December 2007, an outbreak of Chagas' disease occurred in Caracas, Venezuela, related to ingestion of contaminated fruit juices. The objective of this article is to point out the importance of foodborne transmission in the etiology of Chagas' disease, on the basis of published research and Brazilian epidemiology data.
In April 2009, the centenary of the discovery of the American trypanosomiasis, or Chagas disease,... more In April 2009, the centenary of the discovery of the American trypanosomiasis, or Chagas disease, was celebrated. A hundred years after the discovery, little has been invested in diagnostics and treatment because the disease affects mainly poor people in developing countries. However, some changes in the epidemiology of the disease are of great importance today. Chagas disease transmitted through food is a public health concern in all areas where there is a reservoir of Trypanosoma cruzi in wild animals (e.g., mammals and marsupials) and/or where infected triatomine bugs are in contact with human food source items (especially fruits and vegetables). Recently, several outbreaks of illness related to the ingestion of food contaminated with T. cruzi have been recorded in Brazil, Colombia, and Venezuela.
O objetivo deste trabalho foi recuperar e fracionar as proteínas do soro de leite por meio da téc... more O objetivo deste trabalho foi recuperar e fracionar as proteínas do soro de leite por meio da técnica de coacervação, utilizando o polissacarídeo carboximetilcelulose sódica (CMC). O soro de leite foi obtido da fabricação industrial do queijo tipo frescal. Foram estudados concentrações do polímero (0,1% a 0,9% CMC p/v) e valores de pH, a fim de se obter uma precipitação seletiva das proteínas do soro de leite, sendo as condições otimizadas para produção em piloto. Mediante ajuste gradual, foi possível obter, no pH 3, uma precipitação das proteínas totais (PT/CMC); no pH 4, da beta-lactoglobulina (beta-Lg/CMC) e, no pH 3,2, a maior proporção de alfa-lactoalbumina (alfa-La/CMC). Os coacervados foram separados, por aplicação de força centrífuga, e caracterizados em relação à composição centesimal e perfil eletroforético. O maior rendimento foi verificado no fracionamento da beta-lactoglobulina, com 86% de recuperação dessa classe de proteínas do soro desnatado. O coacervado beta-lactog...
Chagas disease is a parasitic infection with high socioeconomic impact throughout Latin America. ... more Chagas disease is a parasitic infection with high socioeconomic impact throughout Latin America. Although this severe, incurable disease can be transmitted by several routes, oral transmission is currently the most important route in the Amazon Basin. Açaí pulp has nutritional properties and is popular throughout Brazil and abroad. However, this pulp has been associated with microepidemics of acute Chagas disease (ACD) in northern Brazil, where açaí fruit is the main food supplement. In this study, we examined the in vitro survival and in vivo virulence of Trypanosoma cruzi Y strain in açaí pulp. Aliquots of in natura açaí pulp produced in Belém city in the northern Brazilian state of Pará were mixed with 10(5) trypomastigotes. The samples were incubated at room temperature or at 4 or -20°C for various periods, and the parasites were isolated by forced sieving. The resulting eluates were examined by microscopy, and the trypomastigotes were administered intraperitoneally, orally, or ...
A peroxidase ea polifenoloxidase estão relacionadas com o escurecimento de frutas, por isso o con... more A peroxidase ea polifenoloxidase estão relacionadas com o escurecimento de frutas, por isso o controle das atividades destas enzimas é de grande importância para a tecnologia de alimentos. Neste trabalho estudaram-se as atividades dessas enzimas nas uvas frescas ...
O consumo de frutas vem crescendo no mercado nacional e internacional, o que esta relacionado ao ... more O consumo de frutas vem crescendo no mercado nacional e internacional, o que esta relacionado ao sabor, as preferencias pessoais e com mudancas no comportamento do consumidor, que se preocupa cada vez mais com a saude, o que promove um aumento na demanda de produtos naturais, de alto valor nutritivo. Um grupo de alimentos que tambem vem ganhando mercado no Brasil sao os alimentos probioticos. O leite e a principal matriz alimenticia utilizada como veiculo para estes micro-organismos e o desenvolvimento de alimentos probioticos de origem nao lactea e uma opcao atrativa diante do crescente numero de consumidores vegetarianos, da intolerância a lactose, e do colesterol presente nos laticinios. Este trabalho teve o objetivo de desenvolver um suco de banana em po e utiliza-lo como veiculo para o micro-organimo probiotico Lactobacillus acidophilus. Uma mistura de pure de banana, maltodextrina, antiumectante e solucao de L. acidophilus foi liofilizada, triturada e armazenada por 90 dias a ...
One of the great challenges of the mango production chain is the maintenance of post-harvest qual... more One of the great challenges of the mango production chain is the maintenance of post-harvest quality of this fruit for export with a focus on food safety. This study evaluated the effect of the hydrothermal treatment associated to ethanol on mango’s quality. Two tests were performed, in both were used ‘Tommy Atkins’ mangoes. In the first one, the heat treatment consisted of immersing the fruits in a bath at 46.1 °C / 75 minutes with ethanol concentrations of 0, 5, 10 and 20% v / v, then a cooling bath at 21.1 °C / 30 minutes and stored at 25 °C. In the second, fruits were submitted to the baths, but with ethanol concentrations of 0, 3, 5 and 7% v/v, and stored at 25°C and 10°C. Physical-chemical and phytopathological analysis and percentage of mango rottenness were evaluated. Mangoes treated with more than 10% ethanol (stored at 25°C), or those treated at ethanol concentrations below 7% (stored at 10°C) did not show good external appearance. It was concluded that ethanol at the conc...
The baru tree fruit has a sustainable economical potential. However, the shelling process to rele... more The baru tree fruit has a sustainable economical potential. However, the shelling process to release the whole kernel, the most valued part of the fruit, is still performed in a rather inefficient way. The objective of this investigation was to determine the physical-mechanical properties of the fruit to understand its behavior during shelling. Fruit and nut were characterized by unit mass, dimensions, volume and bulk, and real densities. Compression tests up to endocarp disruption were performed to determine maximum force, corresponding deformation, and deformation energy. X-ray tomography was used to identify potential nut internal dimension changes, affected by the treatments. Whole fruits and nuts showed average unit mass values of 28.20 ± 0.99 g and 16.52 ± 1.67 g, respectively. Their average dimensions, such as length, width, and thickness were 52.40 ± 4.48 mm, 38.31 ± 4.05 mm, and 28.64 ± 3.67 mm, and 50.78 ± 5.57 mm, 34.65 ± 5.14 mm, and 21.36 ± 2.86 mm, respectively. Averag...
O objetivo deste trabalho foi determinar o efeito de extratos naturais vegetais na germinacao, cr... more O objetivo deste trabalho foi determinar o efeito de extratos naturais vegetais na germinacao, crescimento vegetativo e resistencia termica de esporos de Desulfotomaculum nigrificans, um microrganismo contaminante de acucar e vegetais. A metodologia descrita por Donnelly e Busta (1980) foi utilizada para preparar e ativar 40min/97oC) um lote de esporos de D.nigrificans em Caldo Soytone (CS) e Caldo de Cana (CC), A contagem dos esporas foi realizada em Sulfite Agar em tubos de rosca, ou em Caldo Tioglicalato Fluido com neutralizante pelo metodo do NMP-3; em tubos exaustados, se lados com vaspar e incubados a 55 °C. Dos 29 extratos naturais vegetais ensaiados contra 102esporos/ml, gengibre, angelica, alecrim e eucalipto (EFE) inibiram o crescimento vegetativo a concentracoes de 0,01%v/v ou maiores, e extrato de sementes citricas (ESC) inibiu o crescimento vegetativa a concentracoes de 0,001%v/v ou maiores. Quando a concentracao de esporos de D. nigrificans foi de 105/ml, CSE e EFE mostraram os melhores resultados: 0,1 e l%v/v, respectivamente inibiram o crescimento vegetativa. Somente ESC a 0,001 e 0,0001 %v/v, e EFE a 0,1 e 1 %v/v foram ensaiados na germinacao dos esporos de D.nigrificans em CS e CC pelo metodo da perda da resistencia termica; nas concentracoes ensaiadas nenhum destes extratos demonstraram efeito inibidor sobre a germinacao nestes meios. O efeito de tratamentos termo-quimicos na resistencia dos esporos de D. nigrificans foi avaliado pela adicao de ESC a concentracao de 0,05%v/v em CS (pH 7,6) e CC (pH 5,15) usando a metodo do tubo TDT. ESC diminuiu a resistencia termica dos esporos de D. nigrificans em aproximadamente 5%, 25% e 30%, respectivamente para tratamentos termicos a 115, 120 e 125°C, usando tanto CS como CC. Os valores de D(min) obtidos em CS foram maiores que aqueles obtidos em CC, provavelmente devido ao baixo pH do CC. Os valores de Z(°C) obtidos sao equivalentes aos observados na literatura (8-10°C) para este microrganismo Abstract
Particles may be formed from mixtures of polysaccharides and proteins based on the interaction be... more Particles may be formed from mixtures of polysaccharides and proteins based on the interaction between these biopolymers. They can carry lipophilic bioactive compounds protecting them against gastric conditions and controlling the release of these molecules. This study aimed to produce particles of pectin and alginate coated by electrostatic interaction using isolated soy protein (ISP). These particles were evaluated for their stability by in vitro simulation of gastrointestinal conditions, pH changes and different concentrations of NaCl. The use of an ISP solution at 8% protein concentration resulted in microparticles with high protein content adsorbed (47.61%). The stability test showed that high concentrations of NaCl and low pH destabilized the protein layer with subsequent release to the environment, however, the particles remained intact. The particles coated with isolated soy protein (ISPPart) were resistant to gastric conditions, but were disintegrated in the intestinal envi...
The rheological behaviour of mume pulp at 6, 7, 8 and 9 °Brix was investigated using a rotational... more The rheological behaviour of mume pulp at 6, 7, 8 and 9 °Brix was investigated using a rotational viscometer at temperatures ranging from 15 to 75 °C. The rheological models of Herschel-Bulkley and Ostwald-Waele (Power Law) were fitted to obtain the rheological parameters of the mume pulp. The product was described as time non-dependent and presented a viscosity of 1.9 Pa.s at 15 °C and 1.1°Pa.s at 65 and 75 °C for the 9 °Brix pulp. The pulp showed non-Newtonian behaviour and the Herschel-Bulkley model was used to describe this behaviour. The activation energy ranged from 6.6-10.6 kJ.mol-1 and the consistency index from 18.0-22.9 Pa.s n for the 9 °Brix pulp and 8.3-12.2 Pa.s n for the 8 °Brix pulp at temperatures varying from 15 to 75 °C. The models presented high correlation values for all the rheological data obtained in the present work.O comportamento reológico de polpa de umê, com 6, 7, 8 e 9 °Brix, foi avaliado utilizando-se um viscosímetro rotacional nas temperaturas de 15 a ...
Various researchers have studied the importance of the oral transmission of Chagas' disease s... more Various researchers have studied the importance of the oral transmission of Chagas' disease since the mid-20th century. Only in recent years, due to an outbreak that occurred in the Brazilian State of Santa Catarina in 2005 and to various outbreaks occurring during the last 3 years in the Brazilian Amazon basin, mainly associated with the consumption of Amazonian palm berry or açaí (Euterpe oleracea Mart.) juice, has this transmission route aroused the attention of researchers. Nevertheless, reports published in the 1960s already indicated the possibility of Chagas' disease transmission via food in Brazil, mainly in the Amazonian region. Recently, in December 2007, an outbreak of Chagas' disease occurred in Caracas, Venezuela, related to ingestion of contaminated fruit juices. The objective of this article is to point out the importance of foodborne transmission in the etiology of Chagas' disease, on the basis of published research and Brazilian epidemiology data.
In April 2009, the centenary of the discovery of the American trypanosomiasis, or Chagas disease,... more In April 2009, the centenary of the discovery of the American trypanosomiasis, or Chagas disease, was celebrated. A hundred years after the discovery, little has been invested in diagnostics and treatment because the disease affects mainly poor people in developing countries. However, some changes in the epidemiology of the disease are of great importance today. Chagas disease transmitted through food is a public health concern in all areas where there is a reservoir of Trypanosoma cruzi in wild animals (e.g., mammals and marsupials) and/or where infected triatomine bugs are in contact with human food source items (especially fruits and vegetables). Recently, several outbreaks of illness related to the ingestion of food contaminated with T. cruzi have been recorded in Brazil, Colombia, and Venezuela.
O objetivo deste trabalho foi recuperar e fracionar as proteínas do soro de leite por meio da téc... more O objetivo deste trabalho foi recuperar e fracionar as proteínas do soro de leite por meio da técnica de coacervação, utilizando o polissacarídeo carboximetilcelulose sódica (CMC). O soro de leite foi obtido da fabricação industrial do queijo tipo frescal. Foram estudados concentrações do polímero (0,1% a 0,9% CMC p/v) e valores de pH, a fim de se obter uma precipitação seletiva das proteínas do soro de leite, sendo as condições otimizadas para produção em piloto. Mediante ajuste gradual, foi possível obter, no pH 3, uma precipitação das proteínas totais (PT/CMC); no pH 4, da beta-lactoglobulina (beta-Lg/CMC) e, no pH 3,2, a maior proporção de alfa-lactoalbumina (alfa-La/CMC). Os coacervados foram separados, por aplicação de força centrífuga, e caracterizados em relação à composição centesimal e perfil eletroforético. O maior rendimento foi verificado no fracionamento da beta-lactoglobulina, com 86% de recuperação dessa classe de proteínas do soro desnatado. O coacervado beta-lactog...
Chagas disease is a parasitic infection with high socioeconomic impact throughout Latin America. ... more Chagas disease is a parasitic infection with high socioeconomic impact throughout Latin America. Although this severe, incurable disease can be transmitted by several routes, oral transmission is currently the most important route in the Amazon Basin. Açaí pulp has nutritional properties and is popular throughout Brazil and abroad. However, this pulp has been associated with microepidemics of acute Chagas disease (ACD) in northern Brazil, where açaí fruit is the main food supplement. In this study, we examined the in vitro survival and in vivo virulence of Trypanosoma cruzi Y strain in açaí pulp. Aliquots of in natura açaí pulp produced in Belém city in the northern Brazilian state of Pará were mixed with 10(5) trypomastigotes. The samples were incubated at room temperature or at 4 or -20°C for various periods, and the parasites were isolated by forced sieving. The resulting eluates were examined by microscopy, and the trypomastigotes were administered intraperitoneally, orally, or ...
A peroxidase ea polifenoloxidase estão relacionadas com o escurecimento de frutas, por isso o con... more A peroxidase ea polifenoloxidase estão relacionadas com o escurecimento de frutas, por isso o controle das atividades destas enzimas é de grande importância para a tecnologia de alimentos. Neste trabalho estudaram-se as atividades dessas enzimas nas uvas frescas ...
O consumo de frutas vem crescendo no mercado nacional e internacional, o que esta relacionado ao ... more O consumo de frutas vem crescendo no mercado nacional e internacional, o que esta relacionado ao sabor, as preferencias pessoais e com mudancas no comportamento do consumidor, que se preocupa cada vez mais com a saude, o que promove um aumento na demanda de produtos naturais, de alto valor nutritivo. Um grupo de alimentos que tambem vem ganhando mercado no Brasil sao os alimentos probioticos. O leite e a principal matriz alimenticia utilizada como veiculo para estes micro-organismos e o desenvolvimento de alimentos probioticos de origem nao lactea e uma opcao atrativa diante do crescente numero de consumidores vegetarianos, da intolerância a lactose, e do colesterol presente nos laticinios. Este trabalho teve o objetivo de desenvolver um suco de banana em po e utiliza-lo como veiculo para o micro-organimo probiotico Lactobacillus acidophilus. Uma mistura de pure de banana, maltodextrina, antiumectante e solucao de L. acidophilus foi liofilizada, triturada e armazenada por 90 dias a ...
One of the great challenges of the mango production chain is the maintenance of post-harvest qual... more One of the great challenges of the mango production chain is the maintenance of post-harvest quality of this fruit for export with a focus on food safety. This study evaluated the effect of the hydrothermal treatment associated to ethanol on mango’s quality. Two tests were performed, in both were used ‘Tommy Atkins’ mangoes. In the first one, the heat treatment consisted of immersing the fruits in a bath at 46.1 °C / 75 minutes with ethanol concentrations of 0, 5, 10 and 20% v / v, then a cooling bath at 21.1 °C / 30 minutes and stored at 25 °C. In the second, fruits were submitted to the baths, but with ethanol concentrations of 0, 3, 5 and 7% v/v, and stored at 25°C and 10°C. Physical-chemical and phytopathological analysis and percentage of mango rottenness were evaluated. Mangoes treated with more than 10% ethanol (stored at 25°C), or those treated at ethanol concentrations below 7% (stored at 10°C) did not show good external appearance. It was concluded that ethanol at the conc...
The baru tree fruit has a sustainable economical potential. However, the shelling process to rele... more The baru tree fruit has a sustainable economical potential. However, the shelling process to release the whole kernel, the most valued part of the fruit, is still performed in a rather inefficient way. The objective of this investigation was to determine the physical-mechanical properties of the fruit to understand its behavior during shelling. Fruit and nut were characterized by unit mass, dimensions, volume and bulk, and real densities. Compression tests up to endocarp disruption were performed to determine maximum force, corresponding deformation, and deformation energy. X-ray tomography was used to identify potential nut internal dimension changes, affected by the treatments. Whole fruits and nuts showed average unit mass values of 28.20 ± 0.99 g and 16.52 ± 1.67 g, respectively. Their average dimensions, such as length, width, and thickness were 52.40 ± 4.48 mm, 38.31 ± 4.05 mm, and 28.64 ± 3.67 mm, and 50.78 ± 5.57 mm, 34.65 ± 5.14 mm, and 21.36 ± 2.86 mm, respectively. Averag...
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Papers by Flávio Luís Schmidt