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1.
Curr Res Food Sci ; 5: 298-305, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35198988

RESUMO

The present work was proposal the potential evaluation of Fourier-Transform Mid-Infrared (FT-MIR) associated with chemometric approach in green beans, in order to discriminate the origin of special Arabica coffees in a single state that has heterogeneous environments. Partial Least Squares Discriminant Analysis (PLS-DA) model presented as result: 3 latent variables, R 2 X (cum) = 0.892, R 2 Y (cum) = 0.659; Q 2 Y (cum) = 0.494, RMSEP = 0.182387, p-value CV-Anova = 0.009, 100% of both sensitivity and specificity and the prediction classification obtained was: 100, 83.33, 100, 83.33% for class 1, class 2, class 3 and class 4, respectively. These results can be considered adequate for the proposed hypothesis. The obtained results that the regions have markers such as trigonelline, chlorogenic and fatty acids, sensitive to absorption in the mid-infrared and that are able to determine the origin of green coffee beans of Arabica. Thus, the FT-MIR associated with chemometrics has the potential to employ speed, modernity and cost reduction in the certification of origin of coffees.

2.
Phys Chem Chem Phys ; 22(23): 13118-13122, 2020 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-32490492

RESUMO

Erbium-doped tellurite glass containing copper nanoparticles showed multi-band emission of one particular transition (4I9/2→4I15/2, at 980 nm) due to electron-lattice coupling. The present study reports the vibronic transitions of intraconfigurational 4fn transitions of Er3+ ions in a tellurite host matrix at room temperature for the first time. The mechanisms of multiphoton transitions and the effect of laser heating are discussed here. This unprecedented behavior enables the design of a plethora of different applications spanning from tunable emission in the near infrared, such as lasers for bioimaging and biomedical fields, to energy conversion by thermophotovoltaic conversion of thermal radiation.

3.
Demetra (Rio J.) ; 15(1): 47945, jan.- mar.2020. tab, graf
Artigo em Inglês, Português | LILACS | ID: biblio-1428388

RESUMO

Introdução: O leite é um dos alimentos mais consumidos pelos seres humanos. Proteínas, vitaminas, gordura, carboidratos e sais minerais fazem parte de sua composição e desempenham importantes funções para a nutrição humana. A prática de adulteração no leite é antiga e ainda se faz presente nos dias de hoje em diversos países, inclusive no Brasil. A fim de obter lucro maior, alguns fornecedores costumam adicionar ao leite: água, amido, citrato, ureia, soda cáustica, cloreto de sódio, sacarose, soro do leite, melamina e outros componentes. No entanto, ainda há outro problema, o da contaminação do leite por medicamentos veterinários. Estes podem causar danos à saúde do consumidor e prejuízos para a produção de seus derivados. Objetivo: O presente trabalho propõe uma metodologia que permite detectar de maneira rápida a presença de resíduos de medicamentos veterinários em leites, dentro do limite máximo de resíduos de cada droga. Métodos: Fez-se o uso da espectroscopia no infravermelho próximo por transformada de Fourier associada à análise de componentes principais. A espectroscopia no infravermelho tem sido utilizada não somente para a autenticidade de laticínios, mas para determinar sua qualidade. Resultados: Conseguiu-se detectar resíduos de penicilina, oxitetraciclina e enrofloxacino, e também do antiparasitário ivermectina nas amostras de leites. Conclusão: A metodologia detectou de maneira rápida e precisa os resíduos das drogas analisadas, mesmo em concentrações muito baixas. Assim, é uma opção a outras existentes, já utilizadas para tal objetivo. (AU)


Introduction: Milk is one of the most consumed foods by humans. Proteins, vitamins, fat, carbohydrates and minerals are part of its composition and play important roles in human nutrition. The practice of adulteration in milk is old and is still present today in several countries, including Brazil. In order to obtain a higher profit, some suppliers usually add to the milk: water, starch, citrate, urea, caustic soda, sodium chloride, sucrose, whey, melamine and other components. However, there is still another problem, that of contamination of milk by veterinary medicines. These can cause damage to the health of the consumer and damage to the production of its derivatives. Objective: The present work proposes a methodology that allows to quickly detect the presence of residues of veterinary medicines in milk, within the maximum residue limit of each drug. Methods: The use of spectroscopy in the near infrared by Fourier transform associated with the analysis of principal components was used. Infrared spectroscopy has been used not only for the authenticity of dairy products, but to determine their quality. Results: It was possible to detect residues of penicillin, oxytetracycline and enrofloxacin, and also of the antiparasitic ivermectin in the milk samples. Conclusion: The methodology fastly and accurately detected the residues of the analyzed drugs, even in very low concentrations. Thus, it is an option to other existing ones, already used for this purpose. (AU)


Assuntos
Resíduos de Drogas , Contaminação de Alimentos , Leite , Quimiometria , Anti-Infecciosos , Antiparasitários , Drogas Veterinárias
4.
Food Sci. Technol (SBCTA, Impr.) ; 37(spe): 38-41, Dec. 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-892229

RESUMO

Abstract This work presents the results of a device, MilkTech, developed to detect milk tampering, based on electrical measurements. The device indicates possible frauds by water, sodium chloride, caustic soda, ethyl alcohol and sodium bicarbonate. The advantages in relation to traditional methods are portability, low cost and detection of mixed frauds. The experiments were conducted in dairy plants at Governador Valadares, in Brazil. The results were compared with cryoscopy and chloride tests. It is demonstrated there is high correlation between MilkTech and Cryoscopy. For instance, the detection limit of the equipment for water addition with the set of analyzed data was 0.78% with precision of 1.1%. Adulterations with sodium chloride, caustic soda, ethyl alcohol and sodium bicarbonate are detected qualitatively, even when added with water, and MilkTech indicates "SUSPECT" milk.

5.
Food Chem ; 213: 647-653, 2016 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-27451230

RESUMO

Adulteration of milk with whey is difficult to detect because these two have similar physical and chemical characteristics. The traditional methodologies to monitor this fraud are based on the analysis of caseinomacropeptide. The present study proposes a new approach to detect and quantify this fraud using the fatty acid profiles of milk and whey. Fatty acids C14:0, C16:0, C18:0, C18:1, C18:2 and C18:3 were selected by gas chromatography associated with discriminant analysis to differentiate milk and whey, as they are present in quite different amounts. These six fatty acids were quantified within a short time by capillary zone electrophoresis in a set of adulterated milk samples. The correlation coefficient between the true values of whey addition and the experimental values obtained by this technique was 0.973. The technique is thus useful for the evaluation of milk adulteration with whey, contributing to the quality control of milk in the dairy industry.


Assuntos
Ácidos Graxos/análise , Contaminação de Alimentos/análise , Leite/química , Soro do Leite/química , Animais , Cromatografia Gasosa/métodos , Eletroforese Capilar/métodos , Proteínas do Soro do Leite/análise
6.
Rev. Inst. Adolfo Lutz ; 75: 01-11, 2016. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1489532

RESUMO

The frying by immersion is a widely used cooking process and it improves the food texture and flavor. This study analyzed the initial thermal oxidation in five edible vegetable oils used for frying. Oils samples were heated twice for 30 minutes, at 180 C and then at 240 C simulating the domestic stoves temperatures. The oils decomposition temperatures were determined by TG, being all of them > 250 C. The FA profile was analyzed by GC-FID and a slight decrease of UFA was found in corn and soybean oils. In canola, olive and sunflower oils, UFA was stable after heating treatment. Minor FA decomposition was found in canola oil, and followed by corn, olive, sunflower and soybean oils. NIR spectroscopy analyzes resulted in an extensive bands overlapping. The spectra were modeled by PCA and the oils were classified into two groups: fresh oil and heated oil, mainly by differing in 1900 nm region, associated with the carboxyl signal decrease, which might be related to the initial FA degradation in samples. It could partially understand what occurs to the vegetable oil in the beginning of its thermo-decomposition. These information are useful to consumers, food industry and health surveillance agency.


A fritura por imersão é um processo de cocção utilizado pela inclusão de textura e sabor aos alimentos. Foi analisada a oxidação térmica inicial de cinco óleos vegetais comestíveis utilizados para fritura de imersão. Amostras de óleos foram aquecidas duas vezes por 30 minutos, a 180 ºC e depois a 240 ºC, simulando-se as temperaturas de fogões domésticos. As temperaturas de decomposição dos óleos foram determinadas por TG, sendo > 250 ºC. O perfil de FA foi analisado por GC-FID, detectando-se pequeno decréscimo dos UFA nos óleos de milho e soja. Nos óleos de canola, oliva e girassol, os UFA foram estáveis após o tratamento térmico. A menor decomposição dos FA foi detectado no óleo de canola, seguido de milho, oliva, soja e girassol. Análises por espectroscopia NIR resultaram em grande sobreposição das bandas. Os espectros foram modelados por PCA, classificando-se os óleos em dois grupos: óleo fresco e óleo aquecido, principalmente pelas diferenças na região de 1900 nm, relacionadas ao decréscimo do sinal de carboxilas, e associadas à degradação inicial dos FA nas amostras. Ainda que parcialmente, pode-se entender o que ocorre com os óleos vegetais no início de termo-decomposição, abrangências que são úteis para consumidores, indústria alimentícia e órgão de vigilância sanitária.


Assuntos
Azeite de Oliva/química , Brassica napus/química , Helianthus/química , Temperatura Alta , Tratamento Térmico , Óleo de Milho/química , Óleo de Soja/química , Ácidos Graxos/química , Óleos de Plantas/química
7.
Rev. Inst. Adolfo Lutz (Online) ; 75: 1/11-11/11, 2016. graf, tab, ilus
Artigo em Inglês | LILACS, SES-SP, SESSP-CTDPROD, SES-SP, SESSP-ACVSES, SESSP-IALPROD, SES-SP, SESSP-IALACERVO | ID: biblio-835637

RESUMO

The frying by immersion is a widely used cooking process and it improves the food texture and flavor. This study analyzed the initial thermal oxidation in five edible vegetable oils used forfrying. Oils samples were heated twice for 30 minutes, at 180 °C and then at 240 °C simulating the domestic stoves temperatures. The oils decomposition temperatures were determined byTG, being all of them > 250 °C. The FA profile was analyzed by GC-FID and a slight decrease of UFA was found in corn and soybean oils. In canola, olive and sunflower oils, UFA was stableafter heating treatment. Minor FA decomposition was found in canola oil, and followed by corn, olive, sunflower and soybean oils. NIR spectroscopy analyzes resulted in an extensive bands overlapping. The spectra were modeled by PCA and the oils were classified into two groups: fresh oil and heated oil, mainly by differing in 1900 nm region, associated with the carboxyl signal decrease, which might be related to the initial FA degradation in samples. It could partiallyunderstand what occurs to the vegetable oil in the beginning of its thermo-decomposition. These information are useful to consumers, food industry and health surveillance agency.


A fritura por imersão é um processo de cozimento amplamente utilizado e melhora a textura e o sabor do alimento. Este estudo analisou a oxidação térmica inicial em cinco óleos vegetais comestíveis usados ​​para fritar. As amostras de óleo foram aquecidas duas vezes durante 30 minutos, a 180 ° C e depois a 240 ° C simulando as temperaturas dos fogões domésticos. As temperaturas de decomposição dos óleos foram determinadas por TG, sendo todas elas> 250 ° C. O perfil de FA foi analisado por GC-FID e uma ligeira diminuição de UFA foi encontrada em óleos de milho e de soja. Nos óleos de canola, azeite e girassol, a UFA foi estável após o tratamento térmico. A decomposição menor de FA foi encontrada em óleo de canola, seguido de óleo de milho, azeite, girassol e soja. As análises de espectroscopia NIR resultaram em uma ampla faixa de sobreposição. Os espectros foram modelados por PCA e os óleos foram classificados em dois grupos: óleo fresco e óleo aquecido, principalmente por diferença na região de 1900 nm, associado à diminuição do sinal carboxílico, o que pode estar relacionado à degradação inicial de FA nas amostras. Poderia entender parcialmente o que ocorre ao óleo vegetal no início de sua termo-decomposição. Essas informações são úteis para consumidores, indústria de alimentos e agência de vigilância da saúde.


Assuntos
Monitoramento Ambiental , Tratamento Térmico , Ácidos Graxos , Óleo de Milho , Óleo de Soja , Óleos de Plantas
8.
J Dairy Sci ; 98(6): 3559-67, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25828656

RESUMO

In this work, we assessed the use of confocal Raman microscopy and artificial neural network as a practical method to assess and quantify adulteration of fluid milk by addition of whey. Milk samples with added whey (from 0 to 100%) were prepared, simulating different levels of fraudulent adulteration. All analyses were carried out by direct inspection at the light microscope after depositing drops from each sample on a microscope slide and drying them at room temperature. No pre- or posttreatment (e.g., sample preparation or spectral correction) was required in the analyses. Quantitative determination of adulteration was performed through a feed-forward artificial neural network (ANN). Different ANN configurations were evaluated based on their coefficient of determination (R2) and root mean square error values, which were criteria for selecting the best predictor model. In the selected model, we observed that data from both training and validation subsets presented R2>99.99%, indicating that the combination of confocal Raman microscopy and ANN is a rapid, simple, and efficient method to quantify milk adulteration by whey. Because sample preparation and postprocessing of spectra were not required, the method has potential applications in health surveillance and food quality monitoring.


Assuntos
Análise de Alimentos/métodos , Leite/química , Redes Neurais de Computação , Soro do Leite/química , Animais , Qualidade dos Alimentos , Microscopia Confocal/métodos , Proteínas do Soro do Leite
9.
Rev. bras. ciênc. saúde ; 18(3): 219-224, 2014. ilus, tab, graf
Artigo em Português | LILACS | ID: lil-780233

RESUMO

O leite é um dos alimentos mais consumidos no mundo,principalmente por crianças e idosos. Em 2007, a Polícia Federal realizou uma operação que apontou um gigantesco esquema de fraudes em leites comercializados no Brasil, constatou-se ainda que 1/3 do leite consumido no Brasil não passava por fiscalização. Muitas são as adulterações: adição de água, soda cáustica, cloreto de sódio, entre outros. No entanto, ainda há outro problema, o da contaminação por fármacos veterinários. Estes podem estar presentes em altas concentrações no leite caso este tenha sido ordenhado dentro do período de carência da vaca. O leite contaminado pode causar sérios dados à saúde do consumidor ou então causar prejuízos para a produção de seus derivados. Objetivo: Desenvolver uma técnica complementar para detectar a presença de resíduos de medicamentosveterinários em amostras de leites. Material e Métodos: Atualmente,com o desenvolvimento tecnológico há muitas técnicas de análisemultielementar que permitem estudar os componentes químicos dedeterminadas amostras. O presente trabalho utiliza a técnica deEspectroscopia no Infravermelho Próximo por Transformada de FourierFT-NIR e a Análise de Componentes Principais PCA para detectar apresença de resíduos do medicamento veterinário em leites. Paraisto, simulou-se adulteração do leite com percentuais de (0,1; 0,5 e10)% de fármaco no leite. Resultados: Crioscopia: 0,539 ºH com0,18% de água; leite não ácido pelo teste do Alizarol; pH 6,71; Gordura:3,25%; Proteína: 3,01%; Lactose: 4,55%; Sólidos: 10,80%. Resíduosdo fármaco foram observados via derivada primeira de espectros derefletância, e análise de PCA em níveis inferiores a 1%. Conclusão:o sistema FT-NIR pôde detectar os resíduos dos fármacos estudadosdentro dos percentuais simulados...


Milk is one of most consumed food by human beings,especially children and elderly. In 2007, the Federal Police conductedan operation that showed an enormous fraud scheme in industrializedmilk in Brazil. In addition, they found out that 1/3 of the milk consumedin Brazil did not pass by inspection. There are several ways to adulteratemilk, such as with addition of water, caustic soda, sodium chlorideand others. However, there is another issue, that is, milk contaminationwith veterinary drugs. These drugs may be present in highconcentrations in milk, in case the cow was milked in the clearanceperiod. Contaminated milk can cause damages to consumers’ healthor injury to the production of derivates. Objective: To develop acomplementary technique to detect the presence of residues ofveterinary drugs in milk samples. Material and Methods: currently,given the technological development, there are many techniquesbased on multielement analysis for studying the chemical componentsof different samples. This paper uses the technique of FourierTransform Near Infrared Spectroscopy and the Principal ComponentsAnalysis (PCA) to detect the evidence of residues of veterinarydrugs in milk. To this end, we simulated adulteration in milk withpercentages of 0.1%, 0.5% and 10% drugs in milk. Results: cryoscopy:0.539 ºH with 0.18% water; non-acid milk according to Alizarol test; pH6.71; Fat: 3.25%; Protein: 3.01%; Lactose: 4.55%; Solids: 10.80%.Drug residues were observed via the first derivative of reflectancespectra and PCA analysis at levels below 1%. Conclusion: The resultwas positive indicating that the FT-NIR system can detected theresidues of studied drugs within the simulated percentage...


Assuntos
Humanos , Feminino , Bovinos , Substitutos do Leite Humano , Diclofenaco/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier/estatística & dados numéricos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/veterinária
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