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1.
Chem Soc Rev ; 53(5): 2578-2602, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38305696

RESUMO

Water is known for dissipating electrostatic charges, but it is also a universal agent of matter electrification, creating charged domains in any material contacting or containing it. This new role of water was discovered during the current century. It is proven in a fast-growing number of publications reporting direct experimental measurements of excess charge and electric potential. It is indirectly verified by its success in explaining surprising phenomena in chemical synthesis, electric power generation, metastability, and phase transition kinetics. Additionally, electrification by water is opening the way for developing green technologies that are fully compatible with the environment and have great potential to contribute to sustainability. Electrification by water shows that polyphasic matter is a charge mosaic, converging with the Maxwell-Wagner-Sillars effect, which was discovered one century ago but is still often ignored. Electrified sites in a real system are niches showing various local electrochemical potentials for the charged species. Thus, the electrified mosaics display variable chemical reactivity and mass transfer patterns. Water contributes to interfacial electrification from its singular structural, electric, mixing, adsorption, and absorption properties. A long list of previously unexpected consequences of interfacial electrification includes: "on-water" reactions of chemicals dispersed in water that defy current chemical wisdom; reactions in electrified water microdroplets that do not occur in bulk water, transforming the droplets in microreactors; and lowered surface tension of water, modifying wetting, spreading, adhesion, cohesion, and other properties of matter. Asymmetric capacitors charged by moisture and water are now promising alternative equipment for simultaneously producing electric power and green hydrogen, requiring only ambient thermal energy. Changing surface tension by interfacial electrification also modifies phase-change kinetics, eliminating metastability that is the root of catastrophic electric discharges and destructive explosions. It also changes crystal habits, producing needles and dendrites that shorten battery life. These recent findings derive from a single factor, water's ability to electrify matter, touching on the most relevant aspects of chemistry. They create tremendous scientific opportunities to understand the matter better, and a new chemistry based on electrified interfaces is now emerging.

2.
Langmuir ; 39(16): 5840-5850, 2023 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-37053576

RESUMO

Hygroelectric cells deliver hydrogen, hydrogen peroxide, and electric current simultaneously at room temperature from liquid water or vapor. Different cell arrangements allowed the electrical measurements and the detection and measurement of the reaction products by two methods each. Thermodynamic analysis shows that water dehydrogenation is a non-spontaneous reaction under standard conditions, but it can occur within an open, non-electroneutral system, thus supporting the experimental results. That is a new example of chemical reactivity modification in charged interfaces, analogous to the hydrogen peroxide formation in charged aqueous aerosol droplets. Extension of the experimental methods and the thermodynamic analysis used in this work may allow the prediction of interesting new chemical reactions that are otherwise unexpected. On the other hand, this adds a new facet to the complex behavior of interfaces. Hygroelectric cells shown in this work are built from commodity materials, using standard laboratory or industrial processes that are easily scaled up. Thus, hygroelectricity may eventually become a source of energy and valuable chemicals.

3.
Phys Chem Chem Phys ; 23(47): 26653-26660, 2021 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-34557879

RESUMO

The recent discovery of electromechanical coupling in elastomers showed periodic electrification in phase with rubber stretching but following different electrostatic potential patterns. In this work, a Kelvin electrode monitored silicone and natural rubber electrification for extended periods until the rubber tubing underwent rupture. The electric potential of the rubber follows regular, quasi-sinusoidal patterns at the beginning and during the whole run, except when close to rubber fatigue failure, changing into complex waveforms. The attractors on natural latex and silicone rubber become chaotic at roughly 50 seconds before rubber rupture when the nearby orbits diverge wildly. Thus, mechanical-to-electrical transduction in rubber alerts fatigue failure nearly one minute ahead of the breakdown. Moreover, electrostatic potential maps of stretched rubbers show the electrification of the rupture sites, evidencing the electrostatic contribution to the breakdown. These results show the convenient features of electromechanical coupling in rubbers for the non-contact, real-time prediction of the rubber fatigue failure, adding to the possibility of environmental energy harvesting.

4.
Polymers (Basel) ; 13(15)2021 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-34372003

RESUMO

Many materials and additives perform well as fire retardants and suppressants, but there is an ever-growing list of unfulfilled demands requiring new developments. This work explores the outstanding dispersant and adhesive performances of cellulose to create a new effective fire-retardant: exfoliated and reassembled graphite (ERG). This is a new 2D polyfunctional material formed by drying aqueous dispersions of graphite and cellulose on wood, canvas, and other lignocellulosic materials, thus producing adherent layers that reduce the damage caused by a flame to the substrates. Visual observation, thermal images and surface temperature measurements reveal fast heat transfer away from the flamed spots, suppressing flare formation. Pinewood coated with ERG underwent standard flame resistance tests in an accredited laboratory, reaching the highest possible class for combustible substrates. The fire-retardant performance of ERG derives from its thermal stability in air and from its ability to transfer heat to the environment, by conduction and radiation. This new material may thus lead a new class of flame-retardant coatings based on a hitherto unexplored mechanism for fire retardation and showing several technical advantages: the precursor dispersions are water-based, the raw materials used are commodities, and the production process can be performed on commonly used equipment with minimal waste.

5.
Faraday Discuss ; 227: 105-124, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33300897

RESUMO

Exfoliated and reassembled graphite (ERG) forms macroscopic, high aspect ratio (1 : >106) and highly conductive coating layers that are strongly adherent to paper, wood, cloth, ceramic and other substrates. The coating precursor is an aqueous dispersion of graphite that exfoliates spontaneously in alkaline cellulose solutions, forming stable dispersions. These can be applied to the substrates by using different painting, coating and lithography techniques. The coating morphology changes from highly smooth to porous and rough, depending on the finishing procedure used. Coated paper sheets are flexible and they perform as leads in electrical circuitry and as electrodes in electrodeposition, supercapacitors, hygroelectricity cells and other electrochemical devices suitable for flexible and wearable electronics. These unique properties of ERG are explained as a consequence of the amphiphilic character of cellulose, which allows it to play the roles of exfoliant, dispersant, stabilizer, adhesive and plasticizer, while graphite powder is transformed into a cohesive laminated nanocomposite.

6.
An Acad Bras Cienc ; 91(4): e20181160, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31644645

RESUMO

Sustainable production requires increasing use of raw materials from renewable sources, processed under mild conditions with minimal effluent production. These requirements are satisfied by using materials derived from biomass, in synergy with food and energy production. The possibilities of biomass are continuously enlarged by new findings, as in the intrinsic nanocomposite properties of natural rubber and the amphiphile behavior of cellulose that translated into new functional materials, including high-performance, flexible and conductive non-metallic materials. Other findings are allowing a better understanding of electrostatic phenomena that play a positive role in electrostatic adhesion and cohesion of nanocomposites made from biomass products. Moreover, this should allow the development of safe electrostatic separation techniques, suitable for the fractionation of crude mixtures of biomass residues. A current study on rubber electrostatics is showing its capabilities as a transducer of mechanical energy while providing clues to understand the performance of the dielectric elastomers used in robotic self-sensing actuators.

7.
Langmuir ; 35(24): 7703-7712, 2019 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-31125236

RESUMO

The glass/air interface shows electrical properties that are unexpected for a widely used electrical insulator. The mobility of interfacial charge carriers under 80% relative humidity (RH) is 4.81 × 10-5 m2 s-1 V-1, 3 orders of magnitude higher than the electrophoretic mobility of simple ions in water and less than 2 orders of magnitude lower than the electron mobility in copper metal. This allows the glass/air interface to reach the same potential as a biased contacting metal quickly. The interfacial surface resistance R increases by more than 5 orders of magnitude when the RH decreases from 80 to 2%, following an S-shaped curve with small hysteresis. Moreover, the biased surfaces store charge, as shown by Kelvin potential measurements. Applying an electric field parallel to the surface produces RH-dependent results: under low humidity, the interface behaves as expected for an ideal two-dimensional parallel-plate capacitor, while under high RH, it acquires and maintains excess negative charge, which is lost under low RH. The glass surface morphology and potential distribution change on the glass/air interface under high RH and applied potential, including the extensive elimination of nonglass contaminating particles and potential levelling. All these surprising results are explained by using a protonic-charge-transfer mechanism: mobile protons dissociated from silanol groups migrate rapidly along a field-oriented adsorbed water layer, while the matrix-bound silicate anions remain immobile. Glass may thus be classified as the ionic analogue of a topological insulator but based on structural features and charge-transfer mechanisms different from the chalcogenides that have been receiving great attention in the literature.

8.
Rev. pesqui. cuid. fundam. (Online) ; 10(3): 656-662, jul.-set. 2018. tab
Artigo em Inglês, Português | LILACS, BDENF - Enfermagem | ID: biblio-906239

RESUMO

Objetivo: Descrever a captação, aproveitamento e o perfil das doadoras de Leite Humano em um Banco de leite de um município do Estado do Paraná. Métodos: Estudo epidemiológico de corte transversal com abordagem quantitativa. Os dados foram coletados entre janeiro e fevereiro de 2015, a partir de fichas arquivadas no primeiro ano de funcionamento, 2013-2014. Resultados: As doadoras eram da faixa etária de 26 a 32 anos, casadas, do lar, tinham 1 ou 2 filhos, foram indicadas por serviços de saúde e a principal motivação para a doação foi o excesso de leite. A média de leite doado foi de 1,4 litros, a maioria na fase madura. Houve perda significativa de leite devido a sujidade. Conclusão: Faz-se necessário, o desenvolvimento de ações para a captação de doadoras, para diminuição das perdas de leite e para educação permanente dos profissionais de saúde envolvidos, a fim de otimizar o funcionamento do serviço


Objetivo: Describir la recopilación, el uso y el perfil de la leche humana de donantes en un banco de leche una ciudad de Paraná. Metodos: Estudio epidemiológico de corte transversal con enfoque cuantitativo. Los datos fueron recogidos entre enero y febrero de 2015, a partir de registros archivados en el primer año de funcionamiento, 2013-2014. Resultados: Los donantes eran del grupo de edad de 26-32 años de edad, casado, tenía su casa 1 o 2 niños, fueron indicados por servicios de salud y la principal motivación para la donación fue el exceso de leche. La leche donada promedio fue de 1,4 litros, sobre todo en la fase de madurez. Había una pérdida significativa de la leche debido a la suciedad. Conclusión: Es necesario, por el desarrollo de acciones para atraer donantes para reducir la pérdida de la leche y la educación de los profesionales de la salud involucrados con el fin de optimizar el funcionamiento del servicio de continuar


Objective: The study's goal has been to describe the collection, utilization and profile of human milk donors in a milk bank of a municipality of Paraná State. Methods: It is a cohort epidemiological study with quantitative approach. Data were collected from January to February 2015, based on records filed in the first year of operation, 2013-2014. Results: Donors belonged to age group from 26 to 32 years old; they were married; they had either 1 or 2 children, and have been indicated by health services, where the primary motivation for the donation was the breast milk excess. The donated milk average amount was 1.4 liter (most in the mature phase). There was a significant loss of milk due to dirtiness. Conclusion: It is necessary the development of actions in order to attract donors, reduce milk loss and provide ongoing education for the health professionals involved, aiming to optimize the service operation


Assuntos
Humanos , Feminino , Adulto , Bancos de Leite Humano/economia , Bancos de Leite Humano , Bancos de Leite Humano/estatística & dados numéricos , Aleitamento Materno , Extração de Leite/economia
9.
J Food Sci Technol ; 55(1): 145-156, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29358805

RESUMO

With the objective to evaluate the modifications in the fruit quality, 'Palmer' mangoes were stored at 12.8 °C for 30 days in controlled atmosphere storage that contained a low level of oxygen (5 kPa) which was associated with increasing levels of carbon dioxide CO2 (0, 1, 5, 10, 15 and 20 kPa CO2). Controlled atmosphere storage did not effect mango respiration. However, transfer mangoes, that were previously stored at high levels of CO2 (5 kPa O2 + 15 kPa CO2 and 5 kPa O2 + 20 kPa CO2) to ambient temperature presented higher respiratory rates. No significant effects of increasing CO2 levels on color (L*, chromaticity, and hue angle), firmness, physical-chemical parameter and carbohydrate metabolism (total and reducing sugars, soluble pectin) were observed. After transfer to ambient temperature the mangoes ripened normally without any signs of CO2 injury. Therefore, the increment levels of CO2 neither improved the quality of the 'Palmer' mangoes nor presented a synergistic effect with low-oxygen when compared to 5 kPa O2-control.

10.
Curitiba; s.n; 20171215. 88 p. ilus.
Tese em Português | LILACS, BDENF - Enfermagem | ID: biblio-1127972

RESUMO

Resumo : Trata-se de um estudo de casos múltiplos, de abordagem qualitativa e caráter descritivo, da linha de pesquisa Processo de Cuidar em Saúde e Enfermagem, com o objetivo de apreender sobre as práticas parentais paternas para o cuidado ao filho sob a ótica do pai. Realizado no Município de Curitiba/PR. A coleta de dados, ocorreu de junho a setembro de 2017, por meio de entrevistas semiestruturadas, em Unidades de Saúde da Família, que foram sorteadas uma por Distrito Sanitário, totalizando 10 unidades. A amostra do estudo foi composta por 12 pais de crianças até três anos de idade. Para análise dos dados utilizou-se a técnica analítica do Modelo Lógico do Nível Individual e para apoio, o software Maxqda. A partir dos códigos elencados, emergiram cinco categorias temáticas, sendo elas: A participação do pai e suas sensações no ciclo gravídico-puerperal; Corresponsabilidade doméstica e parental; Oportunidades e Recursos; Atividades parentais paternas; e Ser pai. Os discursos dos pais expressaram o desejo de participar dos cuidados aos filhos, porém encontraram barreiras para exercer esta atividade, como falta de tempo devido às atividades laborais e impedimentos relacionados aos serviços de saúde, que não possuem estrutura física adequada para acolher o pai, e a falta de preparo das equipes para a promoção da parentalidade paterna. Constatou-se que os pais têm dividido mais as tarefas domésticas e de cuidados ao filho com suas companheiras. Eles expressaram o cuidado ao filho como uma experiência boa, mas, apesar deste sentimento positivo, surgiram também o medo e a vergonha nesta atividade. Ser pai, para eles, está relacionado ao vínculo paterno e à responsabilidade, além de considerarem algo que está além da vida e além da consanguinidade. Foram citados elementos que influenciam o exercício da parentalidade, como a história intergeracional; a rede social de apoio, tendo a avó como principal componente desta; a limitação de tempo para o cuidado do filho; a falta de vagas em creches públicas. A presente pesquisa permitiu a compreensão dos fatos que relacionam o pai ao exercício da parentalidade, ela expressa a voz paterna com suas limitações e potencialidades para desempenhar sua função parental. Este reconhecimento pode contribuir para uma reflexão sobre a atuação dos serviços de saúde, em especial o papel da Enfermagem na promoção à parentalidade paterna. Pois é preciso mais que a motivação paterna, são necessárias políticas públicas e ações mais efetivas para auxiliar o pai no desempenho de suas atividades parentais.


Abstract: This study is a multiple case study of qualitative approach and descriptive character, of the Health Care and Nursing Process research line, aiming at understanding paternal parental child care practices from the father's perspective. The research was carried out in the city of Curitiba/PR, Brazil. A Family Health Unit was selected in each Health District for this study, totaling 10 units. The study sample consisted of 12 parents of children up to 3 years of age. The data collection, from June to September 2017, was done using semi-structured interviews. The data analysis was done using the individual-level logic model and the Maxqda software. Five thematic categories developed from the listed codes: The participation of the father and his sensations in the gravidico-puerperal cycle; Domestic and parental co-responsibility; Opportunities and Resources; Paternal parenting chores; and Being a father. The fathers' discourse expressed the desire to participate in child care, but they found barriers to do this activity, for example, lack of time due to work activities, and problems related to the Health Units, which do not have adequate physical structure to receive the father and lack preparation to promote paternal parenting. This study verified that the fathers have been dividing household chores and child care chores with their partners. They reported child care as an enjoyable experience, but despite this positive feeling, fear and shame also appeared in this report. Being a father for them is related to paternal bond and responsibility, and they also consider fatherhood as something beyond life and consanguinity. Intergenerational history; social support network, where the main component is the grandmother; time limitation for child care; and lack of vacancies in public day care centers were mentioned as elements that influence parenting. The paternal discourse showed in this study makes it possible to understand limitations and potentialities experienced in parenting. This recognition can contribute to a discussion on the performance of health centers, especially on the role of Nursing in promoting paternal parenting, as having paternal motivation is not enough, public policies and more effective actions are necessary to help the father in his parenting activities.


Assuntos
Humanos , Masculino , Adulto , Família , Cuidado da Criança , Enfermagem , Poder Familiar , Pai
11.
Langmuir ; 29(3): 892-901, 2013 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-23256838

RESUMO

Top and bottom surfaces of polyethylene (PE) films exposed to corona discharge display large and opposite electrostatic potentials, forming an electric bilayer in agreement with recent and unexpected findings from Zhiqiang et al. Water wetting, chemical composition and roughness of the two surfaces are different. Surprisingly, the bottom surface, opposite to the corona electrode is charged but it is not oxidized, neither is it wetted with water. Moreover, its morphology is unaltered by charging, while the hydrophilic top surface is much rougher with protruding islands that are the result of oxidation followed by phase separation and polymer-polymer dewetting. Common liquids extract the oxidized, hydrophilic material formed at the upper surface, a result that explains the well-known sensitivity of adhesive joints made using corona-treated thermoplastics to liquids, especially water. These results show that poling the surface closer to the corona electrode triggers another but different charge build-up process at the opposite surface. The outcome is another poled PE surface showing high potential but with unchanged chemical composition, morphology and wetting behavior as the pristine surface, thus opening new possibilities for surface engineering.


Assuntos
Bicamadas Lipídicas/química , Polietileno/química , Proteínas/química , Microscopia de Força Atômica , Microscopia Eletrônica de Transmissão , Tamanho da Partícula , Espectrofotometria , Eletricidade Estática , Propriedades de Superfície , Raios X
12.
J Sci Food Agric ; 91(15): 2844-9, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21748733

RESUMO

BACKGROUND: Jaboticaba (Myriciaria jaboticaba (Vell) Berg.) is a highly perishable Brazilian berry with a shelf life of only 2 days under ambient conditions. Low temperatures and controlled atmosphere (CA) have been used to extend the shelf life of perishable fruit. Thus the aim of this study was to determine the effect of CA with varying concentrations of oxygen (1, 5, 10, 15 and 21 kPa) during cold storage (12.5 °C) of 'Sabará' jaboticaba fruit. RESULTS: Atmospheres with lower oxygen concentrations (1 and 5 kPa O(2) ) significantly reduced jaboticaba respiration rate. Fruit stored under these conditions had higher L values, and titratable acidity (TA), and lower ratios of soluble solids content (SSC)/TA. However, at the lowest concentration of oxygen (1 kPa O(2) ), firmness decreased markedly compared to fruits stored at higher O(2) levels (P < 0.05). After only 2 days of storage at ambient temperature jaboticaba received a score of 1.6 (dislike strongly - 1) compared to fruit stored under CA, which scored 7.4 (like moderately - 7). After 9 days of storage, fruit from all treatments remained above the limit of acceptability (score 5) and were rated as 6.2. With respect to appearance, statistical differences between treatments were not observed. The total anthocyanin content was not affected by oxygen concentration but decreased 40.4% during CA storage. CONCLUSION: 'Sabará' jaboticaba fruit can be satisfactorily stored under atmospheres containing 5-21 kPa O(2) at 12.5 °C for up to 6 days.


Assuntos
Atmosfera , Respiração Celular , Conservação de Alimentos/métodos , Armazenamento de Alimentos/métodos , Frutas/metabolismo , Myrtaceae , Oxigênio/metabolismo , Ácidos/metabolismo , Antocianinas/metabolismo , Brasil , Cor , Tecnologia de Alimentos , Frutas/normas , Refrigeração , Solubilidade , Temperatura
13.
Ciênc. agrotec., (Impr.) ; 34(6): 1514-1521, nov.-dez. 2010. graf
Artigo em Português | LILACS | ID: lil-572326

RESUMO

Neste trabalho, objetivou-se testar o efeito de tratamento com fungicidas e sua combinação com hidrotérmico, na conservação e qualidade pós-colheita de mangas 'Palmer' (Mangifera indica L.) armazenadas sob condição ambiente por 12 dias. Os frutos foram colhidos no estádio de maturação fisiológica (coloração da casca vermelha arroxeada) e, imediatamente, transportados para o laboratório, onde foram padronizados quanto à coloração e ausência de injúrias e, em seguida, submetidos ao tratamento hidrotérmico (53° C/10 minutos), com os fungicidas, cloreto de dodecil dimetil amônio 12 por cento a 120 ppm ou imazalil 50 por cento a 1000 ppm, e associações destes tratamentos. Após secagem, as mangas foram armazenadas sob condição de ambiente (23±2° C, 65±5 por cento UR) por 12 dias e analisadas quanto à ocorrência de podridões, aparência, coloração da casca e da polpa, perda de massa, firmeza, taxa respiratória, e teores de sólidos solúveis, acidez titulável e ácido ascórbico da polpa. O experimento foi conduzido em delineamento inteiramente casualizado, disposto em esquema fatorial com 5 x 5, com 4 repetições e unidade experimental composta de 9 frutos. Nos frutos, de todos os tratamentos, não se observou sinais de murchamento até o sexto dia de armazenamento. A associação do tratamento hidrotérmico com fungicidas não se mostrou eficiente no controle de podridões e não afetou o amadurecimento de mangas 'Palmer', que apresentaram vida útil de 10 dias a 23° C, limitada pela aparência.


The objective of this work was to test of effect of treatment with fungicides and its combination with hydrothermal on the conservation and pos-harvest quality of 'Palmer' mangoes (Mangifera indica L.) stored at atmosphere conditions for 12 days. The fruits had been harvested in the stages of physiological maturation (purple-red rind), transferred to the laboratory where they were separated by color and absence of injuries and then underwent hydrothermal (53° C for 10') and/or chemical treatment with the fungicides dodecil dimethyl ammonium chloride at 120 ppm (12 percent) and imazalil at 1000 ppm (50 percent). After drying, fruits were stored at room temperature (23±2° C, 63±5 percent RH) for 12 days and analyzed every three days for rots, appearance, coloration of the rind and the pulp, weight and firmness loss, respiratory rate, and levels of soluble solids, titable acidity and ascorbic acid in the pulp. The experiment was arranged in completely randomized design, in a 5 x 5 factorial scheme, with 4 replicates. Experimental units comprised nine fruits. No withering signs were observed in any of the treatments until the sixth day of storage. The combination of hydrothermal and fungicide treatments were not efficient in controlling rots. A shelf life of ten days was observed in 'Palmer' mangoes stored at 23° C, which was limited by fruit appearance.

14.
Ciênc. agrotec., (Impr.) ; 34(5): 1279-1284, Sept.-Oct. 2010. tab
Artigo em Português | LILACS | ID: lil-567344

RESUMO

Espinhaços de tilápias (Oreochromis niloticus) são partes do peixe de composição desconhecida. A composição lipídica dos espinhaços não é citada na literatura, bem como a estabilidade da farinha do espinhaço durante o armazenamento. Nesse sentido, realizou se estudo de processamento dos espinhaços envolvendo etapas de cocção, trituração, secagem, peneiramento e armazenamento da farinha. A farinha ficou armazenada sob refrigeração por um período de 90 dias, sendo sua qualidade monitorada por meio da composição em ácidos graxos, índice de acidez e análises microbiológicas. Os resultados da composição centesimal foram de 14,2 por cento (umidade), 40,8 por cento (proteína), 18,3 por cento (resíduo mineral fixo) e 25,3 por cento de lipídios totais. Nos lipídios totais foi identificado um total de 24 ácidos graxos, com predominância dos ácidos graxos (porcentagem média) de 27.4 por cento (ácido palmítico, 16:0), 35,15 por cento (ácido oléico, 18:1n-9) e 11,82 por cento (ácido linoléico, 18:2n-6) e, em menor proporção: 0,88 por cento (ácido alfa-linolênico, 18:3n-3), 0,08 por cento (ácido eicosapentaenóico, 20:5n-3) e 0,59 (ácido docosahexaenóico, 22:6n-3). Durante os 90 dias de armazenamento, foram observadas algumas alterações no índice de acidez e composição de alguns ácidos graxos, no entanto, para 60 dias de armazenamento, não foram observadas alterações na composição de nenhum ácido graxo, do índice de acidez e nas análises microbiológicas.


The composition of the tilapia (Oreochromis niloticus) fishbone is unknown. Lipid composition fishbone is not cited in the literature, and neither is the stability of the flour of the fishbone during storage. We studied the processing of fishbone cooking, grinding, drying, sieving and the storage of the flour. The flour was stored in a refrigerator for a period of 90 days, and its quality was monitored through fatty acid composition, acid index and microbiology control. The results of the proximate composition were of 14.2 percent (moisture), 40.8 percent (protein), 18.3 percent (ash), and 25.3 percent total lipids. In the total lipids identified 24 fatty acids were identified, with predominance of the fatty acids (medium percentage) of 27.4 percent (palmitic acid, 16:0), 35.15 percent (oleic acmid, 18:1n-9) and 11.82 percent (linoleic acid , 18:2n-6) and, in smaller proportion: 0.88 percent (alpha-linolenic acid, 18:3n-3), 0.08 percent (eicosapentaenoic acid, 20:5n-3) and 0.59 (docosahexaenoic acid, 22:6n-3). During the 90 days of storage some alterations were observed in the acid index and composition of some fatty acids, however, for 60 days of storage no alterations were observed in the fatty acids composition, acid index, and microbiology control.

15.
Rev. bras. hematol. hemoter ; 32(6): 439-443, 2010. tab
Artigo em Inglês | LILACS | ID: lil-574792

RESUMO

AIM: The objective of this study was to compare the efficiency of lipid extraction and to evaluate the fatty-acid composition in total lipids from human plasma, using a new technique and the established Folch, Lees and Stanley (FLS), Bligh and Dyer (BD), Rose-Gottlieb (RG), and Gerber (GM) methods. METHOD: A new technique, the alternative method, to extract total lipids using a microwave was proposed and evaluated. RESULTS: The total lipids extracted from human plasma varied between 0.19 percent and 0.41 percent; the highest total lipid extracted were obtained by the Folch, Lees and Stanley (0.41 percent), alternative method (0.37 percent) and Rose-Gottlieb (0.36 percent) methods. The Gerber method was ineffective to extract total lipids from human plasma. A total of 24 fatty-acid species were quantified by gas chromatography. Of the methods studied, the highest concentrations were found using the Folch, Lees and Stanley method (p < 0.05). CONCLUSION: The alternative method is a fast lipid-extraction technique that can be used for the identification of human plasma fatty acids, but it is not suitable for their measurement.


OBJETIVO: O objetivo desse estudo foi comparar a eficiência da extração lipídica e avaliar a composição em ácidos graxos nos lipídios totais (LT) no plasma humano usando uma nova técnica e os métodos já conhecidos: Folch, Lees e Stanley (FLS), Bligh e Dyer (BD), Rose-Gottlieb (RG) e Gerber (MG). MÉTODO: A nova técnica para extração de lipídios totais utiza o micro-ondas, método Alternativo (MA). RESULTADOS: Os lipídios totais (LT) extraídos do plasma variaram de 0,19 por cento a 0,41 por cento, os maiores teores foram obtidos por FLS (0,41 por cento), MA (0,37 por cento) e RG (0,36 por cento). O MG foi ineficaz na extração dos lipídios totais do plasma. Um total de 24 espécies de ácidos graxos foi quantificado no plasma por cromatografia em fase gasosa. Entre os métodos estudados, as maiores concentrações de ácidos graxos foram obtidas usando-se o método de FLS (p< 0,05). CONCLUSÃO: O método Alternativo foi considerado uma técnica rápida de extração lipídica, a qual poderá ser utilizada somente na identificação de ácidos graxos em plasma humano, mas não adequado para a quantificação dos mesmos.


Assuntos
Humanos , Ácidos Graxos/análise , Metabolismo dos Lipídeos , Lipídeos/análise , Plasma
16.
J Cosmet Sci ; 60(2): 273-80, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19450426

RESUMO

This study evaluated the performance of five oils and three butters extracted from Brazilian plants with different fatty chain composition on hair mechanical properties, split end formation, combing analysis and gloss measurements. Oil treatment reduced the combing force percentage for wet conditions. However, the hair treated with butters showed poor combing. Except for ucuúba butter, oils and butters used in this work had generally no influence on hair tensile properties. In general, hair treated with oils showed a significant gloss increase and a decrease for split end formation. The fatty acid composition of the oils and butters tested showed an effect on the physicochemical properties of hair.


Assuntos
Ácidos Graxos/química , Preparações para Cabelo/química , Cabelo/química , Óleos de Plantas/química , Ácidos Graxos/farmacologia , Cabelo/efeitos dos fármacos , Preparações para Cabelo/farmacologia , Humanos , Óleos de Plantas/farmacologia , Resistência à Tração
17.
Ciênc. agrotec., (Impr.) ; 31(5): 1423-1429, set.-out. 2007. tab
Artigo em Português | LILACS | ID: lil-466537

RESUMO

Conduziu-se este trabalho, com o objetivo de verificar a influência da temperatura de refrigeração e idade do cacho sobre a conservação e qualidade pós-colheita da banana 'Prata Anã', produzida no Norte de Minas Gerais, visando a exportação. Utilizaram-se frutos de bananeira 'Prata Anã' provenientes do município de Nova Porteirinha, MG. A colheita foi realizada na 16ª, 18ª e 20ª semanas após a emissão floral. Dos cachos colhidos, utilizou-se às segundas pencas, separadas em buquês com 5 frutos, lavados e pesados (18 kg). Em seguida, os frutos foram revestidos com embalagens de polietileno de baixa densidade, com 50m de espessura, sob vácuo parcial, acondicionados em caixas de papelão e distribuídos em paletes. Depois de embalados e paletizados, os frutos foram transportados para a EPAMIG/CTNM, onde foram armazenados em câmaras de refrigeração (10 e 12ºC) e umidade relativa de 95 por cento, por um período de 35 dias, sendo analisados antes e após a refrigeração. O armazenamento de bananas 'Prata Anã', provenientes de cachos com 16, 18 e 20 semanas, por 35 dias a temperaturas de 10 e 12ºC, não promoveu "chilling" nos frutos. A temperatura de 10ºC foi mais eficaz em prevenir a evolução da coloração da casca de bananas provenientes de cachos com 18 semanas, que à temperatura de 12ºC, enquanto as temperaturas de 10 e 12ºC foram igualmente eficientes na contenção da mudança de cor de bananas provenientes de cachos com 16 semanas. Frutos provenientes de cachos com 20 semanas amadureceram desuniformemente, ao longo do armazenamento refrigerado.


This work had, as objective, to verify the influence of refrigeration temperature and bunch age on the conservation and post-harvest quality of the 'Prata Anã' banana produced in the North of Minas Gerais, looking towards exportation. 'Prata Anã' banana tree fruits were used originating from the municipal district of Nova Porteirinha, MG. The crop was harvested in the 16th, 18th and 20th weeks after the floral emission. From the clusters picked, the second bunches was used, separated in clusters with 5 fruits, washed and weighed (18 kg). Soon after, the fruits were wrapped with polyethylene packing of low density with 50mm of thickness under partial vacuum, conditioned in cardboard boxes and distributed on palets. After being wrapped and put on paletes, the fruits were transported to EPAMIG/CTNM, where they were stored in refrigeration chambers at 10 and 12ºC with a relative humidity of 95 percent for a period of 35 days, being analyzed before and after the refrigeration. The storage of 'Prata Anã' bananas, coming from 16, 18 and 20 week-old bunches, for 35 days at temperatures of 10 and 12ºC of did not promote "chilling injury" in the fruits. The 10ºC temperature was more effective in preventing the evolution of the coloration of the peel of bananas coming from 18 week-old bunches than the 12ºC temperature, while temperatures of 10 and 12ºC were equally efficient in the contention of the change of color of bananas coming from 16 week-old bunches. Fruits coming from 20 week-old bunches matured non-uniformly during refrigerated storage.

18.
Arch. latinoam. nutr ; 57(3): 273-277, sept. 2007. tab
Artigo em Inglês | LILACS | ID: lil-481884

RESUMO

This study analyzed the effects of different concentrations of flaxseed oil (FO) on the proximate composition and the contents of alpha-linolenic acid (LNA, 18:3n-3), eicosapentaenoic (EPA, 20:5n-3), and docosahexaenoic (DHA, 22:6n-3) fatty acids in the liver of cultured Nile tilapia (Oreochromis niloticus). During the fivemonth culture period, tilapias were given diets with incremental concentrations of FO (0.00%; 1.25%; 2.50%; 3.75%, and 5.00%) as a replacement of sunflower oil (control). There was no significant difference in moisture and ash content in the liver between treatments. Protein values ranged from 12.1% (treatment II) to 13.9% (treatment V) and total lipids ranged from 5.6% (treatment V) to 7.2% (treatment II). There was no significant difference between most treatments. Fatty acid methyl esters (FAMEs) were quantitatively analyzed by capillary gas chromatography against a C23:0 internal standard. Variations in concentrations (in mg g-1 of total lipids) of fatty acids between treatment I and treatment V ranged from 4.2 to 51.2 (LNA), from 0.2 to 2.3 (EPA), and from 10.6 to 56.2 (DHA), respectively. This experiment demonstrated that increasing amounts of LNA in feed may markedly increase the amounts of LNA, EPA, and DHA in the liver of Nile tilapia.


Este estudio analiza los efectos de diversas concentraciones del aceite de linaza (AL) en la composición centesimal y el contenido del ácido alfa-linolenico (LNA, 18:3 n-3), eicosapentaenoic (EPA, 20:5 n-3), y (DHA, 22:6 n-3), los ácidos grasos docosahexaenoic en el hígado del tilapia del Nilo (Oreochromis niloticus) criada em cautiverio. Durante un período de cinco meses, a las tilapias le fueron administradas dietas con concentraciones crecientes de AL (0,00%; 1,25%; 2,50%; 3,75%, y 5,00%) como reemplazo del aceite de girasol (control). No se encontró diferencia significativa en el contenido de humedad y de ceniza en el hígado entre los tratamientos. Los valores de la proteina variaron entre 12,1% (tratamiento II) y (al tratamiento 13,9% V) y los lípidos totales entre el 5,6% (tratamiento V) y 7,2% (tratamiento II). No se encontró diferencia significativa entre la mayoría de los tratamientos. Los ésteres metílicos de los ácidos grasos (FAMEs) fueron analizados cuantitativamente por cromatografía de gas capilar contra la CA. 23:0 estándares internos. Las variaciones en concentraciones (en mg g-1 de lípidos totales) de ácidos grasos entre el tratamiento I y el tratamiento V variaron entre 4,2 y 51,2 (LNA), 0,2 y 2,3 (EPA), y 10,6 a 56,2 (DHA), respectivamente. Esto experimento demostró que cantidades crecientes de LNA en la alimentación puede aumentar significativamente las cantidades de LNA, de EPA, y de DHA en el hígado de la tilapia del Nilo.


Assuntos
Animais , Ração Animal , Ciclídeos , Gorduras Insaturadas na Dieta/metabolismo , Ácidos Graxos/análise , Óleo de Semente do Linho/administração & dosagem , Fígado/química , Cromatografia Gasosa , Gorduras Insaturadas na Dieta/administração & dosagem
19.
Arch Latinoam Nutr ; 57(3): 273-7, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18271406

RESUMO

This study analyzed the effects of different concentrations of flaxseed oil (FO) on the proximate composition and the contents of alpha-linolenic acid (LNA, 18:3n-3), eicosapentaenoic (EPA, 20:5n-3), and docosahexaenoic (DHA, 22:6n-3) fatty acids in the liver of cultured Nile tilapia (Oreochromis niloticus). During the five-month culture period, tilapias were given diets with incremental concentrations of FO (0.00%; 1.25%; 2.50%; 3.75%, and 5.00%) as a replacement of sunflower oil (control). There was no significant difference in moisture and ash content in the liver between treatments. Protein values ranged from 12.1% (treatment II) to 13.9% (treatment V) and total lipids ranged from 5.6% (treatment V) to 7.2% (treatment II). There was no significant difference between most treatments. Fatty acid methyl esters (FAMEs) were quantitatively analyzed by capillary gas chromatography against a C(23:0), internal standard. Variations in concentrations (in mg g(-1) of total lipids) of fatty acids between treatment I and treatment V ranged from 4.2 to 51.2 (LNA), from 0.2 to 2.3 (EPA), and from 10.6 to 56.2 (DHA), respectively. This experiment demonstrated that increasing amounts of LNA in feed may markedly increase the amounts of LNA, EPA, and DHA in the liver of Nile tilapia.


Assuntos
Ração Animal , Ciclídeos , Gorduras Insaturadas na Dieta/metabolismo , Ácidos Graxos/análise , Óleo de Semente do Linho/administração & dosagem , Fígado/química , Animais , Cromatografia Gasosa , Gorduras Insaturadas na Dieta/administração & dosagem
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