Browsing by Author "Drunkler, Deisy A."
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- Application of an electronic tongue for evaluating basic gustatory attributes perceived in table olives: qualitative and quantitative approachesPublication . Marx, Ítala; Rodrigues, Nuno; Dias, L.G.; Veloso, Ana C.A.; Pereira, J.A.; Drunkler, Deisy A.; Peres, António M.The organolep:c evalua:on of table olives aiming their commercial classifica:on according to sensory trade categories, although not being legally required, is recommended by the Interna:onal Olive Council. This classifica:on is based on the organolep:c evalua:on of nega:ve a\ributes usually found in table olives (and their respec:ve brine solu:ons), performed by trained sensory panels. However, the training and implementa:on of such panels is :me-consuming, costly and has some drawbacks like the low number of samples that can be assessed per day as well as the intrinsic degree of subjec:vity of the evalua:ons carried out by the trained panelists. Besides the percep:on of sensory defects (type and intensity), panelists are usually asked, among other characteris:cs, to assess the intensity of basic gustatory a\ributes (e.g., acid, bi\er and salty), which knowledge is useful for table olives quality control. In this work, and for the first :me, the poten:al use of a home-made electronic tongue for discrimina:ng standard aqueous solu:ons of chemical compounds (obtained with mineral water and in the concentra:on ranges used during sensory panels training sessions) that mimic the 3 basic tastes is evaluated: tartaric and citric acids (0.01 to 2 g/L; for acid taste); caffeine and anhydrous quinine (0.01 to 3 g/L; for bi\er taste); and, sodium and potassium chloride (0.5 to 25 g/L; for salty taste). The results showed that a linear discriminant model based on the poten:ometric signals recorded by a sub-set of 5 sensors (composed by cross-sensi:vity lipidic membranes) could correctly classify the standard solu:ons according to the basic taste mimicked with sensi:vi:es of: (i) 98% for the leave-one-out cross-valida:on; and (ii) 98% ± 3% (ranging from 91% to 100%) for the repeated K-folds cross-valida:on (K = 4 folds with 10 repeats, guaranteeing that 25% of the original data was kept for internal-valida:on purposes). Furthermore, the poten:ometric signal profiles recorded by the electronic tongue during the analysis of table olives and respec:ve brine solu:ons (40 different samples) were used, for the first :me, to quan:ta:vely es:mate the median intensity of the same gustatory a\ributes (acid, bi\er and salty) perceived by a sensory panel (composed by 8 trained panelists) during the simultaneous analysis of table olives and brine solu:ons. The results showed that it was possible to establish sa:sfactory mul:ple linear regression models based on sub-sets of signals gathered during the analysis of the table olives and/or brine solu:ons (varying from 21 to 25 depending on the basic taste), also selected by applying the simulated annealing variable selec:on algorithm: (i) R2 ≥ 0.968 for leave- one-out cross-valida:on; and (ii) R2 ≥ 0.97 ± 0.02 for the repeated K-folds cross-valida:on (K=4 folds with 10 repeats). These preliminary qualita:ve and quan:ta:ve results allow foreseen the prac:cal applica:on of the electronic tongue for assessing gustatory basic tastes on table olive real samples, which could be used as a helpful tool for the hard task required to sensory panelists.
- Application of an electronic tongue for evaluating basic gustatory attributes perceived in table olives: qualitative and quantitative approachesPublication . Marx, Ítala; Rodrigues, Nuno; Dias, L.G.; Veloso, Ana C.A.; Pereira, J.A.; Drunkler, Deisy A.; Peres, António M.The organolep:c evalua:on of table olives aiming their commercial classifica:on according to sensory trade categories, although not being legally required, is recommended by the Interna:onal Olive Council. This classifica:on is based on the organolep:c evalua:on of nega:ve a\ributes usually found in table olives (and their respec:ve brine solu:ons), performed by trained sensory panels. However, the training and implementa:on of such panels is :me-consuming, costly and has some drawbacks like the low number of samples that can be assessed per day as well as the intrinsic degree of subjec:vity of the evalua:ons carried out by the trained panelists. Besides the percep:on of sensory defects (type and intensity), panelists are usually asked, among other characteris:cs, to assess the intensity of basic gustatory a\ributes (e.g., acid, bi\er and salty), which knowledge is useful for table olives quality control. In this work, and for the first :me, the poten:al use of a home-made electronic tongue for discrimina:ng standard aqueous solu:ons of chemical compounds (obtained with mineral water and in the concentra:on ranges used during sensory panels training sessions) that mimic the 3 basic tastes is evaluated: tartaric and citric acids (0.01 to 2 g/L; for acid taste); caffeine and anhydrous quinine (0.01 to 3 g/L; for bi\er taste); and, sodium and potassium chloride (0.5 to 25 g/L; for salty taste). The results showed that a linear discriminant model based on the poten:ometric signals recorded by a sub-set of 5 sensors (composed by cross-sensi:vity lipidic membranes) could correctly classify the standard solu:ons according to the basic taste mimicked with sensi:vi:es of: (i) 98% for the leave-one-out cross-valida:on; and (ii) 98% ± 3% (ranging from 91% to 100%) for the repeated K-folds cross-valida:on (K = 4 folds with 10 repeats, guaranteeing that 25% of the original data was kept for internal-valida:on purposes). Furthermore, the poten:ometric signal profiles recorded by the electronic tongue during the analysis of table olives and respec:ve brine solu:ons (40 different samples) were used, for the first :me, to quan:ta:vely es:mate the median intensity of the same gustatory a\ributes (acid, bi\er and salty) perceived by a sensory panel (composed by 8 trained panelists) during the simultaneous analysis of table olives and brine solu:ons. The results showed that it was possible to establish sa:sfactory mul:ple linear regression models based on sub-sets of signals gathered during the analysis of the table olives and/or brine solu:ons (varying from 21 to 25 depending on the basic taste), also selected by applying the simulated annealing variable selec:on algorithm: (i) R2 ≥ 0.968 for leave- one-out cross-valida:on; and (ii) R2 ≥ 0.97 ± 0.02 for the repeated K-folds cross-valida:on (K=4 folds with 10 repeats). These preliminary qualita:ve and quan:ta:ve results allow foreseen the prac:cal applica:on of the electronic tongue for assessing gustatory basic tastes on table olive real samples, which could be used as a helpful tool for the hard task required to sensory panelists.
- Assessment of Table Olives’ Organoleptic Defect Intensities Based on the Potentiometric Fingerprint Recorded by an Electronic TonguePublication . Marx, Ítala; Rodrigues, Nuno; Dias, L.G.; Veloso, Ana C.A.; Pereira, J.A.; Drunkler, Deisy A.; Peres, António M.Table olives are prone to the appearance of sensory defects that decrease their quality and in some cases result in olives unsuitable for consumption. The evaluation of the type and intensity of the sensory negative attributes of table olives is recommended by the International Olive Council, although not being legally required for commercialization. However, the accomplishment of this task requires the training and implementation of sensory panels according to strict directives, turning out in a time-consuming and expensive procedure that involves a degree of subjectivity. In this work, an electronic tongue is proposed as a taste sensor device for evaluating the intensity of sensory defects of table olives. The potentiometric signal profiles gathered allowed establishing multiple linear regression models, based on the most informative subsets of signals (from 24 to 29 recorded during the analysis of olive aqueous pastes and brine solutions) selected using a simulated annealing meta-heuristic algorithm. The models enabled the prediction of the median intensities (R 2 = 0.942 and RMSE = 0.356, for leave-one-out or repeated K-fold cross-validation procedures) of butyric, musty, putrid, winey-vinegary, and zapateria negative sensations being, in general, the predicted intensities within the range of intensities perceived by the sensory panel. Indeed, based on the predicted mean intensities of the sensory defects, the electrochemical-chemometric approach developed could correctly classify 86.4% of the table olive samples according to their trade category based on a sensory panel evaluation and following the International Olive Council regulations (i.e., extra, 1st choice, 2nd choice, and olives that may not be sold as table olives). So, the satisfactory overall predictions achieved demonstrate that the electronic tongue could be a complementary tool for assessing table olive defects, reducing the effort of trained panelists and minimizing the risk of subjective evaluations.
- Discriminação de soluções padrão de defeitos sensoriais associados à fermentação anormal de azeitonas de mesa recorrendo a uma língua eletrónica e quimiometriaPublication . Marx, Ítala; Rodrigues, Nuno; Dias, L.G.; Veloso, Ana C.A.; Pereira, J.A.; Drunkler, Deisy A.; Peres, António M.De acordo com os dados do Sistema de lnformação sobre o Azeite e a Azeitona de Mesa a produção de azeitonas de mesa em Portugal na campanha 2015-2016 aumentou 11% em relação à última campanha. Atendendo à importância deste produto na fileira oleícola, o Conselho Oleícola lnternacional vem implementando diretrizes para a seleção e treino de painéis sensoriais capazes de classificar o produto de acordo com a intensidade dos defeitos presentes no mesmo. As azeitonas de mesa podem ser classificadas em diferentes categorias comerciais dependendo da mediana das intensidades dos defeitos sensoriais aferidas por painéis treinados. Contudo, atendendo à dificuldade em treinar painéis sensoriais e ao limitado numero de amostras que podem ser avaliadas diariamente pelos mesmos, o desenvolvimento de técnicas analíticas, capazes de identificar os principais defeitos sensoriais presentes em azeitonas de mesa, afigura-se primordial. Neste trabalho, a capacidade de uma língua eletrónica (LE) potenciométrica para distinguir os defeitos associados a fermentação anormal e demonstrada usando soluções padrão dos respetivos defeitos. A LE conjuntamente com um método meta-heurístico de seleção de permitiu estabelecer modelos discriminantes lineares de classificação, com base no perfil de sinais de 5 sensores lípidos de sensibilidade cruzada, capazes de discriminar corretamente soluções padrão correspondentes aos defeitos putrido, butirico e sapateira (100% e 93% para validação cruzada "leave-one-out" e "K-folds" com repetição). Estes resultados preliminares permitem antever a utilização desta ferramenta na análise sensorial de azeitonas de mesa.
- Discriminação de soluções padrão de defeitos sensoriais associados à fermentação anormal de azeitonas de mesa resorrendo a uma Língua Eletrónica e quimiometriaPublication . Marx, Ítala; Rodrigues, Nuno; Dias, L.G.; Veloso, Ana C.A.; Pereira, J.A.; Drunkler, Deisy A.; Peres, António M.De acordo com os dados do Sistema de lnformação sobre o Azeite e a Azeitona de Mesa a produção de azeitonas de mesa em Portugal na campanha 2015-2016 aumentou 11% em relação à última campanha. Atendendo à importância deste produto na fileira oleícola, o Conselho Oleícola lnternacional vem implementando diretrizes para a seleção e treino de painéis sensoriais capazes de classificar o produto de acordo com a intensidade dos defeitos presentes no mesmo. As azeitonas de mesa podem ser classificadas em diferentes categorias comerciais dependendo da mediana das intensidades dos defeitos sensoriais aferidas por painéis treinados. Contudo, atendendo à dificuldade em treinar painéis sensoriais e ao limitado numero de amostras que podem ser avaliadas diariamente pelos mesmos, o desenvolvimento de técnicas analíticas, capazes de identificar os principais defeitos sensoriais presentes em azeitonas de mesa, afigura-se primordial. Neste trabalho, a capacidade de uma língua eletrónica (LE) potenciométrica para distinguir os defeitos associados a fermentação anormal e demonstrada usando soluções padrão dos respetivos defeitos. A LE conjuntamente com um método meta-heurístico de seleção de permitiu estabelecer modelos discriminantes lineares de classificação, com base no perfil de sinais de 5 sensores lípidos de sensibilidade cruzada, capazes de discriminar corretamente soluções padrão correspondentes aos defeitos putrido, butirico e sapateira (100% e 93% para validação cruzada "leave-one-out" e "K-folds" com repetição). Estes resultados preliminares permitem antever a utilização desta ferramenta na análise sensorial de azeitonas de mesa.
- Effect of Lactobacillus plantarum and prebiotics in reduction of aflatoxin B1 in milkPublication . Vasconcelos, R.A.M.; Wochner, Katia F.; Becker-Algeri, Tania Aparecida; Moreira, M.C.; Rodrigues, Paula; Colla, Eliane; Drunkler, Deisy A.The aim of this study was to evaluate the influence of Lactobacillus plantarum isolated and associated with prebiotics (inulin, oligofrutose, β-glucan and polydextrose) on the aflatoxin B1 (AFB1) reduction in artificially contaminated milk.
- Feasibility of L. plantarum and prebiotics on Aflatoxin b1 detoxification in cow milkPublication . Vasconcelos, Rute Alexandra Machado; Kalschne, Daneysa Lahis; Wochner, Katia Francine; Moreira, Maria Clara Cândido; Becker-Algeri, Tania Aparecida; Centenaro, Andressa Inez; Colla, Eliane; Rodrigues, Paula; Drunkler, Deisy A.Milk is a key food worldwide prone to mycotoxins contamination. Lactobacillus plantarum and prebiotics detoxification ability was evaluated by a Plackett-Burman Design considering the reduction of aflatoxin B1 (AFB1) and its bioaccessibility in artificially contaminated ultra-high temperature cow milk. Six variables were evaluated: AFB1 concentration (from 5.0 to 10.0 μg L−1); incubation time (0 to 6 h); and inulin, oligofructose, β-glucan, and polydextrose concentrations (from 0.00 to 0.75%). The reduction in AFB1 ranged from 0% to 55.85% and in vitro bioaccessibility from 15.62% to 51.09%. The greatest reduction in AFB1 occurred by adding L. plantarum combined with inulin, oligofructose and β-glucan. The greatest reduction in bioaccessibility occurred by adding inulin or oligofructose and L. plantarum with a 10.0 μg L−1 AFB1 concentration. A sharp reduction in AFB1 was accompanied by higher bioaccessibility rates, and in this case, bioaccessibility is considered the main factor to ensure a low AFB1 absorption by the body. The best experimental condition was 10.0 µg L-1 AFB1, added of L. plantarum and inulin or oligofructose (0.75%), ensuring > 16% final bioaccessibility. Such results represent a safe AFB1 decontamination level for milk.
- Probiotic and prebiotics: impact on bioavailability of aflatoxin B1 in milkPublication . Vasconcelos, Rute; Wochner, Katia F.; Becker-Algeri, Tania Aparecida; Rodrigues, Paula; Drunkler, Deisy A.Milk represents one of the most important dietary sources of nutrients for humans due to its rich nutritional composition. However, milk consumption is also potentially related to the ingestion of chemical contaminants such as mycotoxins. Aflatoxin B1 (AFB1) is a highly toxic mycotoxin, for both animals and humans. This toxin is frequently detected in milk, and it results from the ingestion of contaminated feed by producing animals. Given its high toxicity, methods of AFB1 decontamination, including the use of probiotic microorganisms, have been tested in milk. But the total amount of ingested contaminant does not always reflect the amount available for absorption (bioavailability), so in vitro digestion models are used to determine human oral bioavailability of food contaminants. Regarding prebiotics, few studies have evaluated the decontamination of action of these compounds and it is suggested further that the probiotics to be synergistic in the removal of mycotoxins.
- Probiótico e prebióticos: impacto na bioacessibilidade de aflatoxina B1 no leitePublication . Vasconcelos, Rute; Wochner, Katia F.; Becker-Algeri, Tania Aparecida; Rodrigues, Paula; Drunkler, Deisy A.Aflatoxina B1 (AFB1) é uma micotoxina altamente tóxica para os animais e os seres humanos. Esta toxina tem sido detetada no leite, e resulta da ingestão de ração contaminada pelo animal produtor. Dada a elevada toxicidade desta micotoxina, a utilização de métodos de descontaminação, com destaque para os probióticos, tem sido testados para redução da sua presença no leite. Mas a quantidade total de um contaminante ingerido nem sempre reflete o valor disponível para absorção (biodisponibilidade ou bioacessibilidade), pelo que são utilizados modelos de digestão in vitro para avaliar a bioacessibilidade oral humana de contaminantes dos alimentos. O objetivo deste estudo foi avaliar a ação do microrganismo probiótico Lactobacillus plantarum BG112 e dos prebióticos oligofrutose, polidextrose, beta-glucana e inulina, isolados ou combinados, na bioacessibilidade da AFB1 após digestão in vitro. Amostras de leite foram fortificadas com a micotoxina e adicionadas dos agentes em estudo. A aflatoxina foi quantificada antes e depois da digestão in vitro das amostras por UHPLC-FL. A adição isolada de L. plantarum em leite contaminado por AFB1 resultou numa bioacessibilidade da AFB1 de 27%, confirmando a capacidade de ligação das bactérias ácido láticas com a AFB1. Em relação aos prebióticos, os valores de bioacessibilidade foram também bastante promissores, variando entre os 15 e os 51 %. O melhor resultado para bioacessibilidade foi demostrando quando introduzidos os prebióticos inulina e oligofrutose individualmente. Em conclusão, a adição de L. plantarum e de prebióticos reduziu a bioacessibilidade da AFB1 em todos os ensaios efetuados.
- Quantification of table olives' acid, bitter and salty tastes using potentiometric electronic tongue fingerprintsPublication . Marx, Ítala; Rodrigues, Nuno; Dias, L.G.; Veloso, Ana C.A.; Pereira, J.A.; Drunkler, Deisy A.; Peres, António M.The intensities of the gustatory attributes of table olives is one of the sensory set of parameters evaluated by trained sensory panels accordingly to the recommendations of the International Olive Council. However this is an expensive and time-consuming process that only allows the evaluation of a limited number of samples per day. So, an electronic tongue coupled with multivariate statistical tools, is proposed for assessing the median intensities of acid, bitter and salty tastes perceived in table olives. The results showed that the device, coupled with linear discriminant analysis, could be used as a taste sensor, allowing classifying aqueous standard solutions according to the three basic tastes (repeated K-fold cross-validation: 98% ± 3% of correct classifications) based on the electrochemical signals of 5 sensors. It was demonstrated that the taste sensor with multiple linear regression models, enabled quantifying the median intensities of the three basic tastes (repeated K-fold cross-validation: R2 0.96 ± 0.04) perceived in table olives by a trained sensory panel, based on the potentiometric fingerprints (21e25 signal profiles) of aqueous olive pastes and brines. The overall satisfactory results showed the electronic tongue potential to assess the intensities of gustatory attributes of table olives, formerly only achievable by sensory panels.