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An electronic tongue for honey classification

Dias, L.G.; Peres, António M.; Vilas-Boas, Miguel; Rocha, Maria A.; Estevinho, Leticia M.; Machado, A.A.S.C.
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.46%
An electronic tongue system was developed based on 20 all-solid-state potentiometric sensors and chemometric data processing, with polymeric membranes applied on solid conducting silver-epoxy supports and a Ag=AgCl reference electrode. The sensor array was applied to 52 commercial honey samples obtained randomly from different regions of Portugal. These samples were analysed independently for their pollen profiles by biological techniques and the data collected with the tongue were evaluated for discrimination of the samples with multivariate statistical methods (principal component analysis and linear discriminant analysis), to investigate whether the device may provide an analytical alternative for classification of honey samples with respect to pollen type, a task which is time consuming and requires skilled labour when performed by biological techniques. It was found that the tongue has a reasonable efficiency for classification of honey samples of the most common three types (with Erica, Echium and Lavandula as predominant pollens). With linear discriminant analysis, the honey samples yielded about 84% classification accuracy and 72% for crossed validation. In this study, the honey samples correctly classified for the different types of the dominant pollen were: 53% for Lavandula...

An electronic tongue taste evaluation: identification of goat milk adulteration with bovine milk

Dias, L.G.; Peres, António M.; Veloso, Ana C.A.; Reis, F.S.; Vilas-Boas, Miguel; Machado, A.A.S.C.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.41%
An electronic tongue with 36 cross-sensibility sensors was built allowing a successful recognition of the five basic taste standards, showing high sensibility to acid, salty and umami taste substances and lower performance to bitter and sweet tastes. The taste recognition capability was afterwards tested in the detection of goat milk adulteration with bovine milk, which is a problem for the dairy industry. This new methodology is an alternative to the classical analyticalmethods used to detect caprine milk adulterations with bovine milk, being a simpler, faster and economical procedure. The different signal profiles recorded by the e-tongue device together with linear discriminant analysis allowed the implementation of a model that could distinguish between rawskim milk groups (goat, cowand goat/cow) with an overall sensibility and specificity of 97% and 93%, respectively. Furthermore, cross-validation showed that the modelwas able to correct classify unknown milk samples with a sensibility and specificity of 87% and 70%, respectively. Additionally, the model robustness was confirmed since it correctly or incorrectly classified milk samples with, respectively, higher and lower probabilities than those that could be expected by chance.

An electronic tongue for juice level evaluation in non-alcoholic beverages

Peres, António M.; Dias, L.G.; Barcelos, Tânia P.; Morais, Jorge Sá; Machado, A.A.S.C.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.46%
An electronic tongue with 36 cross-sensibility polymeric membranes was built and used for semi-quantitative analysis of beverages. The objective was to differentiate 4 non-alcoholic beverage groups with different added fruit juice contents: higher than 30%, between 14%-30%, 5%-10% and 0.1%-2%. A set of 16 Portuguese beverages (4 for each group), purchased in commercial supermarkets, was analyzed and the respective signal profiles recorded by the electronic tongue device. The data obtained were treated by stepwise linear discriminant analysis, allowing a 100% overall correct classification for the original grouped cases and a 93.8% for the “leaving one-out” cross-validation procedure

An electronic tongue for gliadins semi-quantitative detection in foodstuffs

Peres, António M.; Dias, L.G.; Veloso, Ana C.A.; Meirinho, Sofia G.; Morais, Jorge Sá; Machado, A.A.S.C.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.35%
An all-solid-state potentiometric electronic tongue with 36 polymeric membranes has been used for the first time to detect gliadins, which are primarily responsible for gluten intolerance in people suffering from celiac disease. A linear discriminant model, based on the signals of 11 polymeric membranes, selected from the 36 above using a stepwise procedure, was used to semi-quantitatively classify samples of a “Gluten-free” foodstuff (baby milked flour), previously contaminated with known amounts of gliadins (<10, 20–50 or >50 mg/kg), as “Gluten-free”, “Low-Gluten content” or “Gluten-containing”. For this food matrix, the device had sensitivity towards gliadins of 1–2 mg/kg and overall sensitivity and specificity of 77% and 78%, respectively. Moreover, the device never identified an ethanolic extract containing gliadins as “Gluten-free”. Finally, the system also allowed distinguishing “Gluten-free” and “Gluten-containing” foodstuffs (15 foods, including breads, flours, baby milked flours, cookies and breakfast cereals) with an overall sensitivity and specificity greater than 83%, using the signals of only 4 selected polymeric membranes (selected using a stepwise procedure). Since only one “Gluten-containing” foodstuff was misclassified as “Gluten-free”...

Semi-quantitative and quantitative analysis of soft drinks using an electronic tongue

Dias, L.G.; Peres, António M.; Barcelos, Tânia P.; Morais, Jorge Sá; Machado, A.A.S.C.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.35%
A potentiometric electronic tongue with 36 cross-sensibility lipo/polymeric membranes was built and applied for semi-quantitative and quantitative analysis of non-alcoholic beverages. A total of 16 commercial fruit juices (e.g., orange, pineapple, mango and peach) from five different brands were studied. In the semi-quantitative approach, the signal profiles recorded by the device were used together with a stepwise linear discriminant analysis to differentiate four beverage groups with different fruit juice contents: >30%, 14–30%, 6–10% and <4%. The model, with two discriminant functions based on the signals of only four polymeric membranes, explained 99% of the total variability of experimental data and was able to classify the studied samples into the correct group with an overall sensibility and specificity of 100% for the original data, and greater than 93% for the cross-validation procedure. The signals were also used to obtain MLR and PLS calibration models to estimate and predict the concentrations of fructose and glucose in the soft drinks. The linear models established were based on the signals recorded by 16 polymeric membranes and were able to estimate and predict satisfactorily (cross-validation) the concentrations of the two sugars (R2 greater than 0.96 and 0.84...

Determination of ascorbic acid and acetylsalicylic acid in commercial preparations using an electronic tongue

Pereira, Olívia R.; Gomes, Cláudia; Gonçalves, Cristina; Borlido, Diana; Batista, Marta; Teixeira, Tatiana; Dias, Luís G.
Fonte: Instituto Politécnico de Viseu Publicador: Instituto Politécnico de Viseu
Tipo: Conferência ou Objeto de Conferência
POR
Relevância na Pesquisa
66.69%
The electronic tongue is a multi-sensors system used to identify the basic standards of taste, such as sweet, salty, sour and bitter, at levels not detectable by humans. Although the main purpose of electronic tongue is the qualitative analysis, the quantitative analysis of substances in a liquid matrix is also possible, having been the subject of these preliminary studies the application of electronic tongue to pharmaceutical products. In this way, the aim of the current study was the quantitative analysis of ascorbic acid (AA) and acetylsalicylic acid (ASA) in several commercial preparations using an electronic tongue. For that, solutions of standard compounds or of commercial preparations contain ascorbic acid and acetylsalicylic acid were analizes by an electronic tongue. The obtained data were using to determine the concentrations of the solutions thought através do multiple linear regression method. The preliminary tests showed that it is possible to quantify the ascorbic acid in effervescent formulations of vitamin C, using the predictor model obtained by multiple linear regression. In the case of acetylsalicylic acid it was verified that the matrix of the analgesics or antipyretics drugs significantly affect the signs of the electronic tongue. The electronic tongue can be used determined ascorbic acid in effervescent formulations while it is necessary developed more selective sensors to acetylsalicylic acid in order to improve the predictive power of electronic tongue quantification of this compound.

Determination of ascorbic acid and acetylsalicylic acid in commercial preparations using an electronic tongue

Pereira, Olívia R.; Gomes, Cláudia; Gonçalves, Cristina; Borlido, Diana; Batista, Marta; Teixeira, Tatiana; Dias, Luís G.
Fonte: Elsevier Publicador: Elsevier
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
66.69%
The electronic tongue is a multi-sensors system used to identify the basic standards of taste, such as sweet, salty, sour and bitter, at levels not detectable by humans. Although the main purpose of electronic tongue is the qualitative analysis, the quantitative analysis of substances in a liquid matrix is also possible, having been the subject of these preliminary studies the application of electronic tongue to pharmaceutical products. In this way, the aim of the current study was the quantitative analysis of ascorbic acid (AA) and acetylsalicylic acid (ASA) in several commercial preparations using an electronic tongue. Methods: For that, solutions of standard compounds or of commercial preparations contain ascorbic acid and acetylsalicylic acid were analizes by an electronic tongue. The obtained data were using to determine the concentrations of the solutions thought através do multiple linear regression method. Results: The preliminary tests showed that it is possible to quantify the ascorbic acid in effervescent formulations of vitamin C, using the predictor model obtained by multiple linear regression. In the case of acetylsalicylic acid it was verified that the matrix of the analgesics or antipyretics drugs significantly affect the signs of the electronic tongue. Conclusions: The electronic tongue can be used determined ascorbic acid in effervescent formulations while it is necessary developed more selective sensors to acetylsalicylic acid in order to improve the predictive power of electronic tongue quantification of this compound.

Evaluation of healthy and sensory indexes of sweetened beverages using an electronic tongue

Dias, L.G.; Sequeira, Cédric Basílio; Veloso, Ana C.A.; Sousa, Mara E.B.C.; Peres, António M.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.53%
Overconsumption of sugar-sweetened beverages may increase the risk of health problems and so, the evaluation of their glycemic load and fructose-intolerance level is essential since it may allow establishing possible relations between physiologic effects of sugar-rich beverages and health. In this work, an electronic tongue was used to accurately classify beverages according to glycemic load (low, medium or high load) as well to their adequacy for people suffering from fructose malabsorption syndrome (tolerable or not): 100% of correct classifications (leave-one-out cross-validation) using linear discriminant models based on potentiomentric signals selected by a meta-heuristic simulated annealing algorithm. These results may be partially explained by the electronic tongue’s capability to mimic the human sweetness perception and total acid flavor of beverages, which can be related with glycemic load and fructose-intolerance index. Finally, the E-tongue was also applied to quantify, accurately, healthy and sensory indexes using multiple linear regression models (leave-one-out cross-validation: Radj > 0.99) in the following dynamic ranges: 4.7 < glycemic load <= 30; 0.4 < fructose intolerance index <= 1.5; 32 < sweetness perception < 155; 1.3 < total acid flavor...

Single-cultivar extra virgin olive oil classification using a potentiometric electronic tongue

Dias, L.G.; Fernandes, Andreia; Veloso, Ana C.A.; Machado, Adélio; Pereira, J.A.; Peres, António M.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.41%
Label authentication of monovarietal extra virgin olive oils is of great importance. A novel approach based on a potentiometric electronic tongue is proposed to classify oils obtained from single olive cultivars (Portuguese cvs. Cobrançosa, Madural, Verdeal Transmontana; Spanish cvs. Arbequina, Hojiblanca, Picual). A meta-heuristic simulated annealing algorithm was applied to select the most informative sets of sensors to establish predictive linear discriminant models. Olive oils were correctly classified according to olive cultivar (sensitivities greater than 97%) and each Spanish olive oil was satisfactorily discriminated from the Portuguese ones with the exception of cv. Arbequina (sensitivities from 61% to 98%). Also, the discriminant ability was related to the polar compounds contents of olive oils and so, indirectly, with organoleptic properties like bitterness, astringency or pungency. Therefore the proposed E-tongue can be foreseen as a useful auxiliary tool for trained sensory panels for the classification of monovarietal extra virgin olive oils.

Practical procedure for discriminating monofloral honey with a broad pollen profile variability using an electronic tongue

Sousa, Mara E.B.C.; Dias, L.G.; Veloso, Ana C.A.; Estevinho, Leticia M.; Peres, António M.; Machado, Adélio
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.41%
Colour and floral origin are key parameters that may influence the honey market. Monofloral light honeys are more demanded by consumers, mainly due to their flavour, being more valuable for producers due to their higher price when compared to darker honey. The latter usually have a high anti-oxidant content that increases their healthy potential. This work showed that it is possible to correctly classify monofloral honey with a high variability in floral origin with a potentiometric electronic tongue after making a preliminary selection of honey according to their colours: white, amber and dark honey. The results showed that the device had a very satisfactory sensitivity towards floral origin (Castanea sp., Echium sp., Erica sp., Lavandula sp., Prunus sp. and Rubus sp.), allowing a leave-one-out cross validation correct classification of 100%. Therefore, the E-tongue shows potential to be used at analytical laboratory level for honey samples classification according to market and quality parameters,as a practical tool for ensuring monofloral honey authenticity.

Use of copper and gold electrodes as sensitive elements for fabrication of an electronic tongue: Discrimination of wines and whiskies

NOVAKOWSKI, Wander; BERTOTTI, Mauro; PAIXAO, Thiago R. L. C.
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.46%
A low-cost method is proposed to classify wine and whisky samples using a disposable voltammetric electronic tongue that was fabricated using gold and copper substrates and a pattern recognition technique (Principal Component Analysis). The proposed device was successfully used to discriminate between expensive and cheap whisky samples and to detect adulteration processes using only a copper electrode. For wines, the electronic tongue was composed of copper and gold working electrodes and was able to classify three different brands of wine and to make distinctions regarding the wine type, i.e., dry red, soft red, dry white and soft white brands. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.; FAPESP (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo)[2009/07859-1]; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico)

Desenvolvimento de sistemas multissensoriais híbridos, língua e narizes eletrônicos para a avaliação de combustíveis.; Development of multisensor hybrid systems, electronic tongue and electronic noses for fuel evaluation.

Wiziack, Nadja Karolina Leonel
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 13/08/2010 PT
Relevância na Pesquisa
66.53%
A utilização simultânea de diferentes tecnologias de sensores é um método eficiente para aumentar o desempenho de sistemas sensoriais. Com o intuito de contribuir para um melhor controle da qualidade de combustíveis brasileiros, foram desenvolvidos neste trabalho sensores para serem utilizados em Língua e Narizes Eletrônicos. Estes sistemas multissensoriais foram utilizados separadamente, bem como simultaneamente, integrando-os para a avaliação da qualidade de gasolina e etanol. Desse modo, foram fabricados dois tipos de sistemas multissensoriais híbridos. O primeiro sistema foi composto pela integração de uma Língua Eletrônica (LE) e de um Nariz Eletrônico (NE), denominado SH-1. Neste sistema multissensorial, a impedância elétrica do conjunto dos diferentes sensores, baseados em filmes nanoestruturados de diferentes polímeros condutores depositados sobre diferentes microeletrodos de ouro, foi medida simultaneamente no líquido e no vapor de amostras de combustíveis. Já o segundo sistema multissensorial híbrido, SH-2, foi composto pela união de dois tipos de NEs e foi fabricado integrando sensores produzidos a partir de microbalanças de quartzo e de uma matriz de capacitores, ambos funcionalizados com os mesmos materiais sensoativos...

The assessment of the quality of sugar using electronic tongue and machine learning algorithms

Sakata, Tiemi C.; Faceli, Katti; Almeida, Tiago A.; Júnior, Antonio Riul; Steluti, Wanessa M. D. M. F.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Conferência ou Objeto de Conferência Formato: 538-541
ENG
Relevância na Pesquisa
66.48%
The correct classification of sugar according to its physico-chemical characteristics directly influences the value of the product and its acceptance by the market. This study shows that using an electronic tongue system along with established techniques of supervised learning leads to the correct classification of sugar samples according to their qualities. In this paper, we offer two new real, public and non-encoded sugar datasets whose attributes were automatically collected using an electronic tongue, with and without pH controlling. Moreover, we compare the performance achieved by several established machine learning methods. Our experiments were diligently designed to ensure statistically sound results and they indicate that k-nearest neighbors method outperforms other evaluated classifiers and, hence, it can be used as a good baseline for further comparison. © 2012 IEEE.

Development and application of an electronic tongue for detection and monitoring of nitrate, nitrite and ammonium levels in waters

Nuñez, L.; Cetó, X.; Pividori, M. I.; Zanoni, Maria Valnice Boldrin; del Valle, M.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 273-279
ENG
Relevância na Pesquisa
66.46%
This work presents the first study and development of an electronic tongue analysis system for the monitoring of nitrogen stable species: nitrate, nitrite and ammonium in water. The electronic tongue was composed of an array of 15 potentiometric poly(vinyl chloride) membrane sensors sensitive to cations and anions plus an artificial neural network (ANN) response model. The building of the ANN model was performed in a medium containing sodium, potassium, and chloride as interfering ions, thus simulating real environmental samples. The correlation coefficient in the cross-validation of nitrate, nitrite and ammonium was satisfactory in the three cases with values higher than 0.92. Finally, the utility of the proposed system is shown in the monitoring of the photoelectrocatalytic treatment of nitrate. © 2013 Elsevier B.V.

Evaluation of healthy and sensory indexes of sweetened beverages using an electronic tongue

Dias, Luís G.; Sequeira, Cédric; Veloso, Ana C. A.; Sousa, Mara E. B. C.; Peres, A. M.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2014 ENG
Relevância na Pesquisa
66.53%
Overconsumption of sugar-sweetened beverages may increase the risk of health problems and so, the evaluation of their glycemic load and fructose-intolerance level is essential since it may allow establishing possible relations between physiologic effects of sugar-rich beverages and health. In this work, an electronic tongue was used to accurately classify beverages according to glycemic load (low, medium or high load) as well to their adequacy for people suffering from fructose malabsorption syndrome (tolerable or not): 100% of correct classifications (leave-one-out cross-validation) using linear discriminant models based on potentiomentric signals selected by a meta-heuristic simulated annealing algorithm. These results may be partially explained by the electronic tongue’s capability to mimic the human sweetness perception and total acid flavor of beverages, which can be related with glycemic load and fructose-intolerance index. Finally, the E-tongue was also applied to quantify, accurately, healthy and sensory indexes using multiple linear regression models (leave-one-out cross-validation: Radj > 0.99) in the following dynamic ranges: 4.7 < glycemic load ≤ 30; 0.4 < fructose intolerance index ≤ 1.5; 32 < sweetness perception < 155; 1.3 < total acid flavor...

Practical procedure for discriminating monofloral honey with a broad pollen profile variability using an electronic tongue

Sousa, Mara E. B. C.; Dias, Luís G.; Veloso, Ana C. A.; Estevinho, Letícia; Peres, António M.; Machado, Adélio A. S. C.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2014 ENG
Relevância na Pesquisa
66.41%
Colour and floral origin are key parameters that may influence the honey market. Monofloral light honey are more demanded by consumers, mainly due to their flavour, being more valuable for producers due to their higher price when compared to darker honey. The latter usually have a high anti-oxidant content that increases their healthy potential. This work showed that it is possible to correctly classify monofloral honey with a high variability in floral origin with a potentiometric electronic tongue after making a preliminary selection of honey according their colours: white, amber and dark honey. The results showed that the device had a very satisfactory sensitivity towards floral origin (Castanea sp., Echium sp., Erica sp., Lavandula sp., Prunus sp. and Rubus sp.), allowing a leave-one-out cross validation correct classification of 100%. Therefore, the E-tongue shows potential to be used at analytical laboratory level for honey samples classification according to market and quality parameters, as a practical tool for ensuring monofloral honey authenticity.

Single-cultivar extra virgin olive oil classification using a potentiometric electronic tongue

Dias, Luís G.; Fernandes, Andreia; Veloso, Ana C. A.; Machado, Adélio A. S. C.; Pereira, José A.; Peres, António M.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2014 ENG
Relevância na Pesquisa
66.41%
Label authentication of monovarietal extra virgin olive oils is of great importance. A novel approach based on a potentiometric electronic tongue is proposed to classify oils obtained from single olive cultivars (Portuguese cvs. Cobrançosa, Madural, Verdeal Transmontana; Spanish cvs. Arbequina, Hojiblanca, Picual). A meta-heuristic simulated annealing algorithm was applied to select the most informative sets of sensors to establish predictive linear discriminant models. Olive oils were correctly classified according to olive cultivar (sensitivities greater than 97%) and each Spanish olive oil was satisfactorily discriminated from the Portuguese ones with the exception of cv. Arbequina (sensitivities from 61% to 98%). Also, the discriminant ability was related to the polar compounds contents of olive oils and so, indirectly, with organoleptic properties like bitterness, astringency or pungency. Therefore the proposed E-tongue can be foreseen as a useful auxiliary tool for trained sensory panels for the classification of monovarietal extra virgin olive oils.

Electronic tongue system to evaluate flavor of soybean (Glycine Max (L.) Merrill) genotypes

Zoldan,Sandra Maria; Braga,Guilherme de Souza; Fonseca,Fernando Josepetti; Carrão-Panizzi,Mercedes Concórdia
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2014 EN
Relevância na Pesquisa
66.46%
An electronic tongue system was tested as a fast and efficient analytical tool for flavor evaluation of soybean genotypes. Grain samples of 25 soybean lines were analyzed using 0.25 g of milled samples added to 100 mL of distilled water and mixing for one minute on a magnetic stirrer. An aliquot (50 mL) from the filtered liquid was used for the analysis on a pre-fixed frequency of 1 kHz and alternate tension of 50 mV. Two analyses were conducted in a complete randomized design with three replicates. Electrical response (capacitance) of eight polymeric chemical sensors used to analyze the soybean lines were submitted to Principal Component Analysis (PCA). In the spatial distribution of the PCA graphic, the lines close to each other were similar, while the distant ones showed different characteristics. The electronic tongue system was efficient in discriminating flavor of soybean lines.

Electronic tongue system to evaluate flavor of soybean (Glycine max (l.) Merrill) genotypes.

ZOLDAN, S. M.; BRAGA, G. de S.; FONSECA, F. J.; CARRÃO-PANIZZI, M. C.
Fonte: Brazilian Archives of Biology And Technology, Curitiba, v. 57, n. 5, p. 797-802, Sept./Oct. 2014. Publicador: Brazilian Archives of Biology And Technology, Curitiba, v. 57, n. 5, p. 797-802, Sept./Oct. 2014.
Tipo: Artigo em periódico indexado (ALICE)
EN
Relevância na Pesquisa
66.46%
An electronic tongue system was tested as a fast and efficient analytical tool for flavor evaluation of soybean genotypes. Grain samples of 25 soybean lines were analyzed using 0.25 g of milled samples added to 100 mL of distilled water and mixing for one minute on a magnetic stirrer. An aliquot (50 mL) from the filtered liquid was used for the analysis on a pre-fixed frequency of 1 kHz and alternate tension of 50 mV. Two analyses were conducted in a complete randomized design with three replicates. Electrical response (capacitance) of eight polymeric chemical sensors used to analyze the soybean lines were submitted to Principal Component Analysis (PCA). In the spatial distribution of the PCA graphic, the lines close to each other were similar, while the distant ones showed different characteristics. The electronic tongue system was efficient in discriminating flavor of soybean lines.; 2014

Microfluidic electronic tongue

Daikuzono, Cristiane M.; Dantas, Cleber A. R.; Volpati, Diogo; Constantino, Carlos J. L.; Piazzetta, Maria H. O.; Gobbi, Angelo L.; Taylor, David M.; Oliveira, Osvaldo N.; Riul, Antonio
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 1129-1135
ENG
Relevância na Pesquisa
66.56%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Processo FAPESP: 08/06504-2; Fast, simple inspection of liquids such as coffee, wine and body fluids is highly desirable for food, beverage and clinical analysis. Electronic tongues are sensors capable of performing quantitative and qualitative measurements in liquid substances using multivariate analysis tools. Earlier attempts to fulfil this task using only a few drops (microliters) of sample did not yield rational results with non-electrolytes e.g. sucrose (sweetness). We report here the fabrication and testing of a microfluidic e-tongue able to distinguish electrolytes from non-electrolytes, covering also the basic tastes relevant to human gustative perception. The sensitivity of our device is mainly attributed to the ultrathin nature of an array formed by non-selective sensing units. The electronic tongue is composed of an array of sensing units designed with a microchannel stamped in a poly( dimethylsiloxane) (PDMS) matrix and sealed onto gold interdigitated electrodes (IDEs). The IDEs are then coated in situ with a 5-bilayer film deposited by the layer-by-layer (LbL) technique. The cationic layer is derived from polyallylamine chloride (PAH). The anionic layer is either poly(3...