Low-cost gas sensors with polyaniline film for aroma detection

Tiggemann, Lídia; Ballen, Sandra Cristina; Bocalon, Cristian; Graboski, Adriana Márcia; Manzoli, Alexandra; Herrmann, P. S. de P.; Steffens, Juliana; Valduga, Eunice; Steffens, Clarice

doi:10.1016/j.jfoodeng.2016.02.006

Cited by 31 publications

(20 citation statements)

References 32 publications

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“…Lipoxygenase (LOX) pathway is an important pathway for the biosynthesis of aroma‐related esters. Lipoxygenase, hydroperoxide lyase (HPL), and alcohol dehydrogenase (ADH) are key enzymes in the metabolism of aroma‐related esters in fruits (Both, Brackmann, & Thewes, ; Maschietto, Marocco, & Malachova, ; Tiggemann, Ballen, & Bocalon, ). Lipoxygenase can identify the 1,4‐isoprene structure of the unsaturated fatty acids, linoleic acid and linolenic acid, and oxidize the oxyhydroxy fatty acids to provide the substrate for subsequent synthesis of esters (Li et al, ).…”

Section: Resultsmentioning

confidence: 99%

“…The LT-treated was stored at low temperature for 150 days, and then transferred to room temperature conditions for 12 days. Each value is a mean ± SD enzymes in the metabolism of aroma-related esters in fruits (Both, Brackmann, & Thewes, 2014;Maschietto, Marocco, & Malachova, 2015;Tiggemann, Ballen, & Bocalon, 2016). Lipoxygenase can identify the 1,4-isoprene structure of the unsaturated fatty acids, linoleic acid and linolenic acid, and oxidize the oxyhydroxy fatty acids to provide the substrate for subsequent synthesis of esters (Li et al, 2014).…”

Section: Aroma Fading Associated With Differentially Expressed Protmentioning

confidence: 99%

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Proteomic analysis of the potential mechanism of fading of aroma‐related esters in “Nanguo” pears after long‐term refrigeration

et al. 2019

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Low‐temperature storage is a key method for delaying the ripening of “Nanguo” pears. However, the aroma of “Nanguo” pears fades after long‐term refrigeration. We investigated the potential mechanism of fading of aroma in “Nanguo” pears by analyzing differentially expressed proteins in pears stored at room temperature, which had higher level of aromatic esters and those stored at low temperature, having lower esters. We observed that 293 kinds of proteins were down‐regulated and 377 were up‐regulated. Gene ontology analysis showed that proteins in the “catalytic activity,” “metabolic process,” “organelle,” and “membrane” proteins were affected by low temperature. KEGG analysis showed that the differentially expressed proteins were involved in oxidative phosphorylation, carbon and fatty acid metabolism. Real‐time PCR showed that transcription levels of nine selected genes correlated with differentially expressed proteins. The results revealed that the expression of potentially aroma‐related proteins, which are important in further research on improving aroma quality of “Nanguo” pears. Practical applications “Nanguo” pears aroma is an important character for attracting consumers and many proteins are involved in the synthesis of aroma. However, their aroma is lost after cold storage and the quality of fruits is affected by low temperature. It is, therefore, of great significance to study the potential proteins that regulate the aroma of refrigerated “Nanguo” pears. In addition, the study results could provide basic and scientific data for the study of improving the aroma quality and genetic improvement of “Nanguo” pears.

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Section: Resultsmentioning

confidence: 99%

Section: Aroma Fading Associated With Differentially Expressed Protmentioning

confidence: 99%

Proteomic analysis of the potential mechanism of fading of aroma‐related esters in “Nanguo” pears after long‐term refrigeration

et al. 2019

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“…The resulting films had good adhesion due to the chemical bonding between the substrate and polymer film. The fabrication cost of our PANI-PDMS sensor is less than $1 [31,32]. Furthermore, owing to the process simplicity and the applicability for various shape and size casts, our technique allows for mass fabrication of our pH sensor [33].…”

Section: Sensor Fabricationmentioning

confidence: 99%

pH Watch - Leveraging Pulse Oximeters in Existing Wearables for Reusable, Real-time Monitoring of pH in Sweat

Balaji

Chen

Wang

et al. 2019

Proceedings of the 17th Annual International Conference on Mobile Systems, Applications, and Services

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Sweat is a readily accessible bodily fluid for detecting biomarkers such as pH, glucose etc., enabling continuous and non-invasive assessment of the well-being of individuals. Our proposed work aims at leveraging pulse oximeter chips in current-day fitness trackers for real-time continuous monitoring of pH in sweat. We achieve that by fabricating a highly responsive and long-term reusable pH sweat sensor on a flexible material to achieve skin conformity, targeting the sensor to work at the reflected infrared (880nm) and red (660nm) photoplethysmograph (PPG) signal intensities recorded by pulse oximeters. The sensor can be readily mounted atop any wearable with a pulse oximeter. We have successfully demonstrated a low-cost, low-power, highly-responsive and longterm reusable wrist-worn wearable prototype, pH Watch, for realtime continuous monitoring of pH value of sweat. We conducted on-body trials with 10 participants and pH Watch achieves an accuracy of ≈91%. We also showed that the integration of our sweat sensor does not hinder the pulse oximeter from measuring heart rate and SpO 2 , and users can continue with their daily activities with motion artifacts removed efficiently from PPG signals using the TROIKA framework, resulting in heart rate and SpO 2 measurements with an accuracy of ≈95% and ≈96% respectively when validated against commercial finger pulse oximeter measurements. To the best of our knowledge, pH Watch is the first demonstration of a reusable sweat sensor that can be readily integrated into today's smart watches with pulse oximeters, paving the way for ubiquitous sensing of biomarkers. * Both authors contributed equally to this research.• Human-centered computing → Ubiquitous and mobile devices; • Applied computing → Health care information systems.

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“…23 Esta medida é muitas vezes realizada em painéis de análise sensorial, nos quais pessoas são empregadas para avaliar as características do produto. 33,34 Métodos sensoriais de medida, no entanto, apesar de serem muito importantes e largamente empregados, parecem perder a precisão desejável em pesquisa científica em função da variabilidade inerente à avaliação individual de cada pessoa envolvida. Assim, o emprego de equipamentos capazes de realizar medidas mais objetivas e que possam pelo menos complementar a análise tradicional na avaliação da qualidade de produtos alimentícios é desejável.…”

Section: Avaliação Sensorial Dos éSteres Formados Durante As Reações unclassified

“…Neste caso, o uso de sensor olfativo artificial mostra-se como uma técnica promissora, pois permite detectar os diferentes aromas presentes no produto final, bem como monitorar a uniformidade e consistência dos aromas formados durante o processo. 34 Desta forma, os aromas dos três componentes, ácido caprílico, óleo fúsel e ésteres formados pela esterificação do ácido caprílico com óleo fúsel foram avaliados pelos sensores gerando o perfil mostrado na Figura 4.…”

Section: Avaliação Sensorial Dos éSteres Formados Durante As Reações unclassified

Síntese enzimática do caprilato de isopentila utilizando óleo fúsel como matéria-prima

Bôas¹,

Biaggio²,

Giordani³

et al. 2017

Quim. Nova

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publicado na web em 24/03/2017 ENZYMATIC SYNTHESIS OF ISOPENTYL CAPRYLATE USING FUSEL OIL AS FEEDSTOCK. Four commercial lipase preparations immobilized by covalent attachment on epoxy-polysiloxane-β-cyclodextrin were tested as potential biocatalysts to mediate the esterification reaction of isopentanol with caprylic acid in solvent-free medium. Among them, the immobilized lipase from Rhizopus oryzae was the most active biocatalyst, attained ester conversion higher than 80% in 24 h, being selected for subsequent tests using fusel oil as source of isopentanol. An experimental design was performed and the analysis of the results revealed that the formation of the isopentyl caprylate was strongly influenced by the variable molar ratio at 95% of confidence level. The proposed mathematical model allowed predicting that the excess of caprylic acid (molar ratio fusel oil to acid of 1:1.5) and reaction temperature of 45 °C favor the reaction to attain high ester conversion. Sensory evaluation of the flavors profile in relation to all the components involved in the reaction (caprylic acid, fusel oil and esters) showed that the formed esters had distinct aromas from the starting materials, confirming that the changes in flavors occurred before and after esterification reactions.Keywords: isopentyl caprylate; immobilized lipase; fusel oil; optimization; esterification. INTRODUÇÃOEntre os diversos subprodutos gerados pela Indústria Sucroalcooleira, o óleo fúsel apresenta amplo potencial de reaproveitamento devido sua composição rica em alcoóis superiores e elevado volume gerado (120 milhões de litros/ ano). 1Apesar do seu aproveitamento não atuar diretamente na redução do custo final do álcool, sua utilização como insumo nas indústrias de transformação certamente representa um importante passo para aumentar a eficiência global da produção industrial do etanol. Atualmente, a taxa de recuperação do óleo fúsel é de apenas 25% do total produzido no país, ou seja, 30 milhões de litros/ ano.3 Possíveis alternativas para o aproveitamento deste subproduto incluem a produção de alcoóis superiores por destilação fracionada, 4 e síntese de ésteres por via química ou biotecnológica. [5][6][7] Ésteres são componentes importantes de aromas naturais e contribuem na formação e acentuação dos aromas em diversos alimentos. 8-11Com a demanda crescente de produtos naturais, a indústria de alimentos está interessada no uso da rota biotecnológica para produção de ésteres aromatizantes.11 Desta forma, é crescente o interesse da aplicação de catalisadores bioquímicos em síntese orgânica, 8-10 entre os quais especial atenção tem sido dedicada às enzimas lipolíticas (lipases e esterases), em função da elevada atividade catalítica exibida em diversos meios não convencionais. 9,10A síntese catalisada por lipases (glicerol éster hidrolases EC 3.1.1.3) de mais de 50 ésteres de aromatizantes já foi descrita na literatura 8,11 e, em princípio, a reação pode ser conduzida em meio reacional constituído de álcool e ácido carboxílico em presença ou ausência de...

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Low-cost gas sensors with polyaniline film for aroma detection

Cited by 31 publications

References 32 publications

Proteomic analysis of the potential mechanism of fading of aroma‐related esters in “Nanguo” pears after long‐term refrigeration

Proteomic analysis of the potential mechanism of fading of aroma‐related esters in “Nanguo” pears after long‐term refrigeration

pH Watch - Leveraging Pulse Oximeters in Existing Wearables for Reusable, Real-time Monitoring of pH in Sweat

Síntese enzimática do caprilato de isopentila utilizando óleo fúsel como matéria-prima

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