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‣ Ascorbic acid and pectin in different sizes and parts of citric fruits; Ácido ascórbico e pectina em diferentes partes de frutas cítricas de vários tamanhos

YWASSAKI, Larissa Akemi; CANNIATTI-BRAZACA, Solange Guidolin
Fonte: Sociedade Brasileira de Ciência e Tecnologia de Alimentos Publicador: Sociedade Brasileira de Ciência e Tecnologia de Alimentos
Tipo: Artigo de Revista Científica
Português
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Citric fruits - in natura, as frozen pulp or even as juice - are one of the most important Brazilian exportation products. They are a source of ascorbic acid - a potent antioxidant, and pectin, which is used in the food industry and is an important dietary fiber. This project aims to quantify ascorbic acid and pectin contents in citric fruits, commercial oranges and tangerines, comparing them in sizes and varieties. Ascorbic acid amount was measured in juice comparing sizes, varieties and storage conditions, using a tritimetric method with 2.6-dichlorobenzenoindophenol indicator. Total and soluble pectin in each part of the fruits (peel, albedo, pulp and juice) were quantified using the polygalacturonic acid as a standard. Differences were found between the sizes. The highest content of vitamin C was found in the oranges (Bahia variety). Comparing the storage temperatures, the biggest loss was at room temperature. Albedo presented the highest content of pectin in all fruits. In juice, the total and soluble pectin contents increased as fruits size decreased. Oranges and tangerines differed in the amount of pectin; Os produtos de frutas cítricas são de grande importância para as exportações do Brasil in natura, polpa congelada e ainda na forma de suco. São fonte de ácido ascórbico...

‣ Effect of the Partial Substitution of Soy Proteins by Highly Methyl-esterified Pectin on Chemical and Sensory Characteristics of Sausages

PEREIRA, C. M.; MARQUES, M. F.; HATANO, M. K.; CASTRO, I. A.
Fonte: SAGE PUBLICATIONS LTD Publicador: SAGE PUBLICATIONS LTD
Tipo: Artigo de Revista Científica
Português
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Pectin can be used as a natural emulsifier in food formulations. In this study, textured soybean protein (TSP), used as an emulsifier in commercial sausages, was partially replaced by a mixture containing pectin and isolated soybean proteins, which were either extruded (EXT) or not extruded (MIX), and the chemical and sensory characteristics of samples were evaluated after 60 days of storage at 4 degrees C. Responses such as oxidation measured by PV and TBARS, hardness, color, pH and sensory characteristics were compared with those of a commercial sausage (CON). The mixture containing highly methyl-esterified pectin, textured soybean proteins and isolated soybean proteins, as emulsifier agent, reduced the hardness (EXT: 21.69 +/- 0.98 and MIX: 20.17 +/- 2.76 N) and the pH (EXT: 5.46 +/- 0.03 and MIX: 5.29 +/- 0.01) of the samples and increased the concentration of peroxides (EXT: 0.10 +/- 0.01 and MIX: 0.15 +/- 0.01 meq/kg) when compared with samples formulated only with TSP (28.57 +/- 2.54 N, pH of 6.92 +/- 0.04 and PV = 0.07 +/- 0.01 meq/kg). These effects were likely caused by the anionic character of the emulsifier. However, no sensory difference was observed between the sausages containing highly methyl-esterified pectin, textured soybean proteins and isolated soybean proteins submitted to the extrusion process (EXT) and the control sausages...

‣ Effect of extrusion on the emulsifying properties of soybean proteins and pectin mixtures modelled by response surface methodology

BUENO, Arthur Soares; PEREIRA, Cristina Meyer; MENEGASSI, Bruna; AREAS, Jose Alfredo Gomes; CASTRO, Inar Alves
Fonte: ELSEVIER SCI LTD Publicador: ELSEVIER SCI LTD
Tipo: Artigo de Revista Científica
Português
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The objective of this study was to apply response surface methodology to estimate the emulsifying capacity and stability of mixtures containing isolated and textured soybean proteins combined with pectin and to evaluate if the extrusion process affects these interfacial properties. A simplex-centroid design was applied to the model emulsifying activity index (EAI), average droplet size (D-[4.3]) and creaming inhibition (Cl%) of the mixtures. All models were significant and able to explain more than 86% of the variation. The high predictive capacity of the models was also confirmed. The mean values for EAI, D-[4.3] and Cl% observed in all assays were 0.173 +/- 0.015 mn, 19.2 +/- 1.0 mu m and 53.3 +/- 2.6%, respectively. No synergism was observed between the three compounds. This result can be attributed to the low soybean protein solubility at pH 6.2 (<35%). Pectin was the most important variable for improving all responses. The emulsifying capacity of the mixture increased 41% after extrusion. Our results showed that pectin could substitute or improve the emulsifying properties of the soybean proteins and that the extrusion brings additional advantage to interfacial properties of this combination. (C) 2008 Elsevier Ltd. All rights reserved.; FAPESP[06/00384-0...

‣ Plasticized pectin-based gel electrolytes

ANDRADE, Juliana R.; RAPHAEL, Ellen; PAWLICKA, Agnieszka
Fonte: PERGAMON-ELSEVIER SCIENCE LTD Publicador: PERGAMON-ELSEVIER SCIENCE LTD
Tipo: Artigo de Revista Científica
Português
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Pectin is a natural polymer present in plants and, as all natural polymers has biodegradation properties. Chemically, pectin is a polysaccharide composed of a linear chain of 1 -> 4 linked galacturonic acids, which is esterified with methanol at 80%. The pectin-based gel electrolytes in a transparent film form were obtained by a plasticization process with glycerol and addition of LiClO(4). The films showed good ionic conductivity results, which increased from 10(-5) S/cm for the samples with 37 wt.% of glycerol to 4.7 x 10(-4) S/cm at room temperature for the sample with 68 wt.% of glycerol. The electrochemical behaviors of the samples were studied by electrochemical impedance spectroscopy (EIS), and Nyquist graphs are showed and discussed. The obtained pectin-based samples also presented good adherence to the glass, flexibility, homogeneity (SEM) and transparency (about 70% in the vis) properties. They are good candidates to be applied as gel electrolytes in electrochromic devices. (C) 2009 Elsevier Ltd. All rights reserved.; FAPESP; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); CNPq; Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); CAPES; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

‣ Misturas aquosas de pectina/caseína: estudo físico-químico e potencial de uso no tratamento da doença periodontal; Pectin/casein aqueous mixtures: physical-chemical studies and potential use in periodontal disease treatment.

Rediguieri, Camila Fracalossi
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 25/04/2008 Português
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Misturas aquosas de polissacarídeos e proteínas são normalmente instáveis e separam-se em fases devido às interações repulsivas ou atrativas existentes entre os polímeros. O efeito da temperatura, do pH e da concentração polimérica no comportamento de misturas de pectina/caseína foi estudado nesse trabalho. Um diagrama de fases construído em pH 7 revelou que a mistura é estável apenas em baixas concentrações. Concentrações mais elevadas levam à incompatibilidade termodinâmica, governada por forças puramente entrópicas, e ao aparecimento de duas fases: uma rica em caseína (inferior) e outra rica em pectina (superior). A decomposição espinodal pôde ser visualizada nos estágios iniciais da separação de fases e, nos estágios intermediários, observou-se a formação de emulsões água/água. Quando o pH dessas emulsões é reduzido para abaixo de 6, a pectina é atraída para a fase de caseína, resultando na formação de partículas de complexo pectina/caseína que não coalescem e são resistentes à adição de sal (NaCl 100 mM), apresentando um diâmetro médio aproximado de 4 m. As micropartículas de pectina/caseína produzidas por este método demonstraram ser capazes de encapsular com alta eficiência tanto substâncias hidrofóbicas quanto hidrofílicas...

‣ Complexo pectina/caseína: aspectos básicos e aplicados; Pectin/casein complex: basic and functional aspects

Camilo, Katyana França Bonini
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 17/12/2007 Português
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Os sistemas de liberação de fármacos são parte integrante da investigação farmacêutica. Grande ênfase tem sido dada à utilização de polímeros hidrofílicos naturais como carreadores devido às vantagens inerentes a seu baixo custo, biocompatibilidade e segurança de uso. Os objetivos principais deste trabalho foram a preparação e avaliação de sistemas microparticulados a base de pectina e caseína e o estudo da liberação in vitro do aciclovir contido nas micropartículas. Esses sistemas visam uma liberação prolongada do fármaco aumentando sua biodisponibilidade oral. O efeito de parâmetros como pH, força iônica, viscosidade, proporção e concentração total de polímeros foi avaliado. A melhor condição para ocorrência da coacervação foi determinada por mobilidade eletroforética, rendimento do coacervado e microscopia ótica. A pectina e a caseína podem interagir formando complexos insolúveis. A formação do complexo coacervado foi espontânea e ocorreu em condições brandas no intervalo de pH em que os polímeros encontram-se carregados com cargas opostas. As dispersões foram secas em Spray dryer, resultando em partículas bastante pequenas (6µm) e homogêneas. Através da microscopia ótica foi possível observar que o fármaco se encontrava no interior das micropartículas. O pH (4...

‣ Eletrólitos poliméricos géis à base de pectina; Polymer electrolytes gel based on pectin

Andrade, Juliana Ramos de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 23/07/2010 Português
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Esta dissertação apresenta a preparação e caracterização de eletrólitos poliméricos géis (EPGs) a partir de pectina comercial GENU®, plastificada com glicerol e dopada com perclorato de lítio. O objetivo é a utilização de uma nova matéria-prima para a obtenção de eletrólitos poliméricos substituindo os polímeros sintéticos. A pectina é um polímero natural presente nas plantas; quimicamente é um polímero heterogêneo, e estruturalmente, é constituída unidades repetidas de (1→4)-α-D-ácido galacturônico. Os eletrólitos foram preparados usando como sal LiClO4 (0,24 g ou 30 [O]/[Li]), e 0,6 g de pectina com diferentes quantidades de glicerol (0 g - 2,0 g; 0% - 70%) como plastificante. Os filmes foram caracterizados por espectroscopia de impedância, difração de raios-X, UV-Vis, FT-IR, análises térmicas (DSC e TG). Os melhores resultados foram apresentados pelos filmes constituídos com 70% de glicerol e 30 [O]/[Li] e 68% de glicerol e 0,24 g de LiClO4. .Os filmes com 68% de glicerol apresentam valores de condutividade iônica de 1,61x10-4 S.cm-1 em temperatura ambiente aumentando para 1,72x10-3 S.cm-1 à 80°C, e uma transmitância de 80% no intervalo do visível. Os valores da energia de ativação para este filme é em torno de 37 KJmol-1. Também foi verificada a estabilidade eletroquímica em uma faixa de potencial que varia entre -1...

‣ Pectin and pectinases: Production, characterization and industrial application of microbial pectinolytic enzymes

Pedrolli, Danielle Biscaro; Monteiro, Alexandre Costa; Gomes, Eleni; Carmona, Eleonora Cano
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Revisão Formato: 9-18
Português
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Pectinases are a big group of enzymes that break down pectic polysaccharides of plant tissues into simpler molecules like galacturonic acids. It has long been used to increase yields and clarity of fruit juices. Since pectic substances are a very complex macromolecule group, various pectinolytic enzymes are required to degrade it completely. These enzymes present differences in their cleavage mode and specificity being basically classified into two main groups that act on pectin smooth regions or on pectin hairy regions. Pectinases are one of the most widely distributed enzymes in bacteria, fungi and plants. This review describes the pectinolytic enzymes and their substrates, the microbial pectinase production and characterization, and the industrial application of these enzymes. © Pedrolli et al.; Licensee Bentham Open.

‣ Purification and biochemical characterization of an alkaline pectin lyase from Fusarium decemcellulare MTCC 2079 suitable for Crotolaria juncea fiber retting

Yadav, Sangeeta; Dubey, Amit Kumar; Anand, Gautam; Kumar, Reetesh; Yadav, Dinesh
Fonte: Wiley-Blackwell Publicador: Wiley-Blackwell
Tipo: Artigo de Revista Científica Formato: S161-S169
Português
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An extracellular pectin lyase secreted by Fusarium decemcellulare MTCC 2079 under solid state fermentation condition has been purified to electrophoretic homogeniety by using ammonium sulfate fractionation, carboxymethyl cellulose and gel filtration (Sephadex G-100) column chromatographies. The purified enzyme showed single protein band corresponding to molecular mass 45 +/- 01 kDa on sodium dodecyl sulfate polyacrylamide gel electrophoresis. The enzyme had maximum activity at pH 9.0 and showed maximum stability in the pH range of 9.0-12.0. The optimum temperature of the purified enzyme was 50 degrees C and it showed maximum stability upto 40 degrees C. The energy of activation for the thermal denaturation (Ea) was 59.06 kJ mol(-1) K-1. The K-m and k(cat) values using citrus pectin as the substrate were 0.125mgml(-1) and 72.9 s(-1) in 100mM sodium carbonate buffer pH 9.0 at 50 degrees C. The biophysical studies on pectin lyase showed that its secondary structure belongs to alpha+beta class of protein with comparatively less of beta-sheets. Purified pectin lyase showed efficient retting of Crotolaria juncea fibers.

‣ Preparação e caracterização de partículas coloidais de pectina cítrica e de peptonas vegetais para aplicação em cosméticos; Preparation and characterization of colloidal particles of citrus pectin and vegetable peptones for use in cosmetics

Renata Miliani Martinez
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 30/07/2013 Português
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O uso de matérias-primas sustentáveis, biodegradáveis e biocompatíveis é de grande interesse em aplicações farmacêuticas e cosméticas. O mercado cosmético situa-se em pleno processo de desenvolvimento, principalmente na área de produtos capilares, apresentando vendas expressivas no Brasil. Esse crescimento acarreta na necessidade de produtos inovadores, polivalentes e seguros para oferecimento aos consumidores. Neste âmbito, as partículas poliméricas coloidais têm ocupado posição de destaque no cenário mundial, marcando a presença da nanotecnologia em produtos cosméticos. Uma grande variedade de matérias-primas naturais ou sintéticas são polieletrólitos, cuja reticulação eletrostática em condições controladas produz partículas coloidais. A pectina cítrica e as peptonas vegetais fazem parte dos polieletrólitos, cuja origem vegetal tem sido preferida para as aplicações em cosméticos, em substituição a produtos de origem animal ou inorgânica. Neste trabalho, foi estudada a produção de partículas coloidais de pectina cítrica e das peptonas de soja e trigo, reticuladas com cloreto de cálcio e goma guar quaternizada. Em todos os casos, a produção das partículas foi realizada em processo descontínuo...

‣ Complexos dos polieletrólitos quitosana e pectina para obtenção de sistemas carreadores de compostos bioativos; Polyelectrolyte complex chitosan and pectin for obtaining carriers systems of bioactive compounds

Vinicius Borges Vieira Maciel
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 13/05/2015 Português
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Complexos de polieletrólitos (PEC) podem ser obtidos a partir de polímeros que apresentam cargas opostas, como quitosana e pectina. A inovação deste trabalho foi desenvolver sistemas carreadores de compostos bioativos (antocianina (ATH) e insulina), na forma de membranas e nanocomplexos (NCXs) obtidos a partir da interação eletrostática existente entre os polímeros naturais quitosana e pectina. Quitosana é um polímero linear catiônico composto por N-glucosamina e N-acetilglucosamina, e apresenta diferentes graus de acetilação (GA). Pectina é um polímero linear aniônico composto principalmente por ácido D-galacturônico com uma fração dos grupos carboxilas sendo metoxilados. Membranas PEC foram desenvolvidas para incorporar a ATH formando um dispositivo inteligente indicador de pH, com alteração visual e reversível da cor. NCXs foram elaborados na forma de micro/nanopartículas carregadas de insulina (pI = 5,3) para avaliar a liberação controlada do fármaco, via oral, em sistemas in vitro. Membranas PEC foram estudadas usando quitosana e pectina em diferentes pH (3,0, 4,0, 5,0 e 5,5) e relações molares pectina:quitosana. Soluções de pectina e quitosana, ambas de 0,50 g/100 g de solução e mesma força iônica foram misturadas e homogeneizadas. As membranas PEC apresentaram superfície rugosa e parcialmente homogênea. A máxima formação do PEC foi em pH 5...

‣ Sugar-cane juice induces pectin lyase and polygalacturonase in Penicillium griseoroseum

Minussi,Rosana Cristina; Soares-Ramos,Juliana Rocha Lopes; Coelho,Jorge Luiz Cavalcante; Silva,Daison Olzany
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/1998 Português
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The use of other inducers as substitutes for pectin was studied aiming to reduce the production costs of pectic enzymes. The effects of sugar-cane juice on the production of pectin lyase (PL) and polygalacturonase (PG) by Penicillium griseoroseum were investigated. The fungus was cultured in a mineral medium (pH 6.3) in a rotary shaker (150 rpm) for 48 h at 25oC. Culture media were supplemented with yeast extract and sucrose or sugar-cane juice. Sugar-cane juice added singly to the medium promoted higher PL activity and mycelial dry weight when compared to pectin and the use of sugar-cane juice and yeast extract yielded levels of PG activity that were similar to those obtained with sucrose-yeast extract or pectin. The results indicated that, even at low concentrations, sugar-cane juice was capable of inducing pectin lyase and polygalacturonase with no cellulase activity in P. griseoroseum.

‣ Ascorbic acid and pectin in different sizes and parts of citric fruits

Ywassaki,Larissa Akemi; Canniatti-Brazaca,Solange Guidolin
Fonte: Sociedade Brasileira de Ciência e Tecnologia de Alimentos Publicador: Sociedade Brasileira de Ciência e Tecnologia de Alimentos
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2011 Português
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Citric fruits - in natura, as frozen pulp or even as juice - are one of the most important Brazilian exportation products. They are a source of ascorbic acid - a potent antioxidant, and pectin, which is used in the food industry and is an important dietary fiber. This project aims to quantify ascorbic acid and pectin contents in citric fruits, commercial oranges and tangerines, comparing them in sizes and varieties. Ascorbic acid amount was measured in juice comparing sizes, varieties and storage conditions, using a tritimetric method with 2.6-dichlorobenzenoindophenol indicator. Total and soluble pectin in each part of the fruits (peel, albedo, pulp and juice) were quantified using the polygalacturonic acid as a standard. Differences were found between the sizes. The highest content of vitamin C was found in the oranges (Bahia variety). Comparing the storage temperatures, the biggest loss was at room temperature. Albedo presented the highest content of pectin in all fruits. In juice, the total and soluble pectin contents increased as fruits size decreased. Oranges and tangerines differed in the amount of pectin

‣ Determination of pectin methylesterase activity in commercial pectinases and study of the inactivation kinetics through two potentiometric procedures

Gonzalez,Samantha Lemke; Rosso,Neiva Deliberali
Fonte: Sociedade Brasileira de Ciência e Tecnologia de Alimentos Publicador: Sociedade Brasileira de Ciência e Tecnologia de Alimentos
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2011 Português
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Pectinases are enzymes that degrade pectic substances and are widely used in juice and fruit beverages to improve the quality of the process. The objective of this study was to determine the optimum pH and temperature of two samples of commercial pectinases and propose an alternative procedure to determine the residual activity comparing the data with those of the traditional procedure. The pectin methylesterase (PME) activity in Pectinex 100 L Plus and Panzyn Clears was determined by potentiometry. The reaction consisted of 5.00 mg.mL-1 apple pectin, 0.100 mol.L-1 NaCl, and 50 µL enzyme to a total volume of 30 mL. The pectin reaction in the presence of PME in all experiments revealed a first order kinetics. The PME in the two enzyme preparations showed higher activity at pH 4.0 to 4.5 and temperature of 45 ºC. From the results of both procedures ΔV NaOH/Δt and ΔpH/Δt, it was concluded that the inactivation of PME occurred at 75 ºC. The results obtained from the ratio ΔpH/Δt showed good correlation with those obtained from the ratio ΔV NaOH/Δt. In the reaction accompanied by the ratio ΔpH/Δt, the release of H3O+ occurred in the real time reaction.

‣ Pectin degradation in ripening and wounded fruits

HUBER,DONALD J.; KARAKURT,YASAR; JEONG,JIWON
Fonte: Sociedade Brasileira de Fisiologia Vegetal Publicador: Sociedade Brasileira de Fisiologia Vegetal
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2001 Português
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Pectin depolymerization during fruit ripening has been shown to be largely due to pectinolytic enzymes, including polygalacturonases (E.C. 3.2.1.15) and pectinmethylesterases (E.C. 3.2.1.11). Studies have shown that these enzymes are not the primary determinants of softening, although participation in texture changes during the late stages of ripening seems evident. Pectin depolymerization differs significantly between various fruit types, notably avocado and tomato, even though levels of extractable PG activity in these fruits are similar. Collective evidence indicates that the activities of some cell wall enzymes are restricted in vivo, with maximum hydrolytic potential expressed only in response to tissue disruption or wounding. In contrast, other enzymes reported to participate in pectin degradation, notably beta-galactosidases/exo-galactanases, exhibit in vitro activity far below that anticipated to be required for the loss of cell wall galactosyl residues during ripening. Factors controlling in vivo hydrolysis have not been fully explored but might include apoplastic pH, cell wall inorganic ion levels, non-enzymic proteins including the noncatalytic beta-subunit and expansins, wall porosity, and steric hindrances. Recent studies of cell wall metabolism during ripening have demonstrated an orderly process involving...

‣ Extraction of pectin from apple pomace

Canteri-Schemin,Maria Helene; Fertonani,Heloísa Cristina Ramos; Waszczynskyj,Nina; Wosiacki,Gilvan
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2005 Português
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As apple-processing units are now in expansion in Brazil, industrial by-products like pomace play an important role in pectin manufacture. The objective of this article was to determine a pratical follow-up to the extraction of pectin from apple pomace and to characterize it in a laboratory, on a small scale, aiming at establishing the optimum conditions for acid extraction. The highest yields were obtained when [1]apple pomace was dried and ground to obtain an apple flour to be used as raw material, [2] citric or nitric acids were used and [3] when the citric acid concentration was 6.2 g/100 ml and the time of reaction was 153 minutes. The apple variety in itself was not significant in pectin yield. The degree of esterification (DE = 68.84 %) of the product obtained, as well as its physical looks, show the success of pectin extraction.

‣ Efeito das condições de extração sobre rendimento e características da pectina obtida de diferentes frações de goiaba CV Pedro Sato; Effect of extraction conditions on yields and characteristics of the pectin obtained from different fractions of guava CV Pedro Sato

MUNHOZ, Claudia Leite
Fonte: Universidade Federal de Goiás; BR; UFG; Mestrado em Ciência e Tecnologia de Alimentos; Ciencias Agrárias - Agronomia Publicador: Universidade Federal de Goiás; BR; UFG; Mestrado em Ciência e Tecnologia de Alimentos; Ciencias Agrárias - Agronomia
Tipo: Dissertação Formato: application/pdf
Português
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The objectives of this study were to characterize the raw material in nature, the flours of fractions of guava cv Pedro Sato and to optimize the factors that influence the yields of pectin extraction of flour of the guava pulp and pulp with peel. As characterize pectins obtained in optimal points on the degree of esterification, comparing them with the commercial pectin. Fruits were used for pectin.extraction. The fruits were divided in peel, pulp, pulp with peel and flesh, dry in stove with circulation of air. Samples in nature and drought were characterized physically and chemically. The central rotation composed design with four axial points and three replicates in the central point was used to optimize the extraction of pectin of flour of the guava pulp and pulp with peel. The extraction was performed in 4 g of flour to 200 mL of solution of citric acid at different concentrations and at different times of extraction, at temperature of 97 ° C. The esterification degree of extracted pectins was compared to commercial pectin one. The highest yields in the extractions of pectin of flour of the guava pulp and pulp with peel were obtained with citric acid solution at 5 g (100 g)-1 and the extraction time of 60 min. Pectins showed up with low esterification...

‣ Enhancement of quality and stability of dried papaya by pectin-based coatings as air-drying pretreatment

Canizares, Diego; Mauro, Maria Aparecida
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica Formato: 1187-1197
Português
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Processo FAPESP: Proc 07/07586-0; Edible coatings have rarely been studied as a pretreatment for air-drying process. Hydrocolloid-based coatings possess good barrier properties to gases, are soluble in water, and can incorporate additives such as ascorbic acid. The aim of the present study was to improve the physical and nutritional characteristics of dehydrated fruits and vegetables by edible coating application. For this, the drying kinetics and the vitamin C and color retention in papaya (Carica papaya L.) with and without edible coatings were evaluated. Color and vitamin C were analyzed after 3, 9, and 30 days of storage. Papaya slices were immersed in a 2 % pectin solution (w/w) or in a 2 % pectin solution with vitamin C (1 % w/w). The pectin coating was gelled by immersion in calcium lactate solution (2.8 % w/w). The pectin-coated and non-coated slices were air-dried at temperatures of 60 and 70 A degrees C. Vitamin C, color, and water content were analyzed in fresh papaya and in coated papaya before and after drying and during storage. All drying experiments were repeated four times. Analysis of variance was applied to the experimental data to identify differences at a 5 % significance level. The drying kinetics of coated and non-coated samples were very similar...

‣ Orange pectin mediated growth and stability of aqueous gold and silver nanocolloids

Nigoghossian, Karina; Santos, Moliria Vieira dos; Barud, Hernane Silva; Silva, Robson Rosa da; Rocha, Lucas Alonso; Caiut, José Maurício Almeida; Assunção, Rosana Maria Nascimento de; Spanhel, Lubomir; Poulain, Marcel; Messaddeq, Younes; Ribeiro, Sidn
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 28-36
Português
Relevância na Pesquisa
37.39444%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); The role of orange based pectin in the nucleation and growth of silver and gold nanoparticles is addressed. Pectin is a complex polysaccharide found in fruits such as oranges, lemons, passion fruits or apples. It displays smooth and hairy chain regions containing hydroxyl-, ester-, carboxylate-and eventually amine groups that can act as surface ligands interacting under various pH conditions more or less efficiently with growing nanometals. Here, a high methoxy pectin (>50% esterified) was used as a stabilizer/reducing agent in the preparation of gold, silver and silver-gold nanoparticles. Commercial pectin (CP) and pectin extracted from orange bagasse (OP) were used. Optionally, trisodium citrate or oxalic acid we used to reduce AgNO3 and HAuCl4 in aqueous environment. Characterization methods included UV-vis absorption spectroscopy, transmission electron microscopy, electron diffraction and energy-dispersive X-ray spectroscopy. The results show that under different pH conditions, pectin and reducing agents allow producing various nanostructures shapes (triangles, spheres, rods, octahedrons and decahedrons) often with high polydispersity and sizes ranging between 5 nm and 30 nm. In addition...

‣ How to let go: pectin and plant cell adhesion

Daher, Firas Bou; Braybrook, Siobhan A.
Fonte: Frontiers Publicador: Frontiers
Tipo: Article; published version
Português
Relevância na Pesquisa
37.359739%
This is the final version of the article. It first appeared from Frontiers via http://dx.doi.org/10.3389/fpls.2015.00523; Plant cells do not, in general, migrate. They maintain a fixed position relative to their neighbours, intimately linked through growth and differentiation. The mediator of this connection, the pectin-rich middle lamella, is deposited during cell division and maintained throughout the cell?s life to protect tissue integrity. The maintenance of adhesion requires cell wall modification and is dependent on the actin cytoskeleton. There are developmental processes that require cell separation, such as organ abscission, dehiscence, and ripening. In these instances, the pectin-rich middle lamella must be actively altered to allow cell separation, a process which also requires cell wall modification. In this review, we will focus on the role of pectin and its modification in cell adhesion and separation. Recent insights gained in pectin gel mechanics will be discussed in relation to existing knowledge of pectin chemistry as it relates to cell adhesion. As a whole, we hope to begin defining the physical mechanisms behind a cells? ability to hang on, and how it lets go.; The writing of this review was carried out with the help of grant BB-L002884-1 (BBSRC...