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DYNAMIC AND STEADY-SHEAR RHEOLOGICAL PROPERTIES OF XANTHAN AND GUAR GUMS DISPERSED IN YELLOW PASSION FRUIT PULP (Passiflora edulis f. flavicarpa)

MORAES, I. C. F.; FASOLIN, L. H.; CUNHA, R. L.; MENEGALLI, F. C.
Fonte: BRAZILIAN SOC CHEMICAL ENG Publicador: BRAZILIAN SOC CHEMICAL ENG
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
86.71%
Yellow passion fruit pulp is unstable, presenting phase separation that can be avoided by the addition of hydrocolloids. For this purpose, xanthan and guar gum [0.3, 0.7 and 1.0% (w/w)] were added to yellow passion fruit pulp and the changes in the dynamic and steady-shear rheological behavior evaluated. Xanthan dispersions showed a more pronounced pseudoplasticity and the presence of yield stress, which was not observed in the guar gum dispersions. Cross model fitting to flow curves showed that the xanthan suspensions also had higher zero shear viscosity than the guar suspensions, and, for both gums, an increase in temperature led to lower values for this parameter. The gums showed different behavior as a function of temperature in the range of 5-35 degrees C. The activation energy of the apparent viscosity was dependent on the shear rate and gum concentration for guar, whereas for xanthan these values only varied with the concentration. The mechanical spectra were well described by the generalized Maxwell model and the xanthan dispersions showed a more elastic character than the guar dispersions, with higher values for the relaxation time. Xanthan was characterized as a weak gel, while guar presented a concentrated solution behavior. The simultaneous evaluation of temperature and concentration showed a stronger influence of the polysaccharide concentration on the apparent viscosity and the G` and G `` moduli than the variation in temperature.

Quantification of isoorientin and total flavonoids in Passiflora edulis fruit pulp by HPLC-UV/DAD

ZERAIK, M. L.; YARIWAKE, J. H.
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
86.81%
A method is reported for the quantification of isoorientin (using a standard addition method) and total flavonoids (expressed as rutin, using the external standard method) in passion fruit pulp (Passiflora edulis Sims f. flavicarpa Degener, Passifloraceae). Extraction of flavonoids was optimized by experimental design methodology, and quantitative analysis was performed by high-performance liquid chromatography with photo-diode array detection (HPLC-UV/DAD). The method was developed and validated according to ICH requirements for specificity, linearity, accuracy, precision (repeatability and intermediate precision). LOD and LOQ. Rutin was chosen as standard for the quantification of total flavonoids in order to propose a HPLC method feasible for routine analysis of the flavonoids in the passion fruit pulp. The passion fruit pulp contained 16.226 +/- 0.050 mg L(-1) of isoorientin and 158.037 +/- 0.602 mg L(-1) of total flavonoid, suggesting that P. edulis fruits may be comparable with other flavonoid food sources such as orange juice or sugarcane juice. (C) 2010 Elsevier B.V. All rights reserved.

Estudo analítico dos flavonoides dos frutos do maracujá (Passiflora edulis Sims f. flavicarpa Degener); Analytical studies of the flavonoids in passion fruit (Passiflora edulis Sims f. flavicarpa Degener)

Zeraik, Maria Luiza
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 16/04/2010 PT
Relevância na Pesquisa
66.9%
Atualmente tem-se dado grande ênfase aos alimentos funcionais, pois atuam na prevenção e auxiliam na recuperação de várias doenças, como doenças inflamatórias crônicas, cardiovasculares e câncer, por apresentarem principalmente flavonoides, que previnem lesões oxidativas, propiciando benefícios à saúde. O Brasil é o maior produtor mundial do maracujá, e em vista disto é de suma importância o desenvolvimento de métodos analíticos e estudos de atividade antioxidante e anti-inflamatória do fruto de maracujá, visando sua possível utilização como alimento funcional e produção de possíveis fármacos. Passiflora edulis Sims. f. flavicarpa Degener, conhecida como maracujá azedo ou amarelo é a espécie mais cultivada e comercializada no Brasil. Desta forma, os objetivos deste trabalho foram: desenvolver e validar um método analítico por CLAE-UV/DAD (cromatografia líquida de alta eficiência acoplada detector de arranjo de fotodiodos) para quantificação da flavona isoorientina, presente na polpa de P. edulis; quantificação dos flavonoides totais desta espécie, usando um padrão de baixo custo (rutina); comparar as técnicas CLAE e CCDAE (cromatografia em camada delgada de alta eficiência) e analisar a isoorientina nas cascas dos frutos de P. edulis infectada com o vírus PWV e cascas sadias por CCDAE; quantificar as proteínas totais e avaliar as atividades antioxidantes e anti-inflamatória dos extratos de cascas de P. edulis e da polpa dos frutos de P. edulis e P. alata...

Aproveitamento de subprodutos da industrialização do maracujá para elaboração de iogurte; Use of industrial byproducts of passion fruit for preparing yogurt

Toledo, Nataly Maria Viva 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 19/08/2013 PT
Relevância na Pesquisa
76.93%
As indústrias beneficiadoras de frutas são responsáveis por gerar grandes quantidades de resíduos, entre eles, os do maracujá. A polpa do maracujá é um dos principais produtos comercializados a partir da fruta, sendo as cascas e sementes os subprodutos resultantes de seu processamento. O objetivo deste trabalho foi desenvolver iogurte com adição de polpa e farinha de maracujá elaborada a partir dos subprodutos da industrialização da fruta. No total, foram avaliadas sete amostras de iogurte dentre as quais cinco apresentavam em sua composição a farinha de maracujá. Foram realizadas análises físico-químicas, microbiológicas, verificação de resíduos de agrotóxicos, teste de aceitação sensorial, verificação da intenção de compra, análise descritiva quantitativa (ADQ), estimativa da vida útil e elaboração dos rótulos dos produtos. Todos os iogurtes adicionados de farinha apresentaram elevados teores de fibra alimentar. Não foram detectados resíduos de agrotóxicos nas amostras do subproduto do maracujá. Observou-se que a incorporação da farinha de maracujá apresentou efeitos positivos na viscosidade e teor de minerais do iogurte, e negativos para aspectos como cor e pH. Verificou-se maior aceitação dos provadores para o iogurte sem adição de farinha. No entanto...

Volatile compounds from organic and conventional passion fruit (Passiflora edulis F. Flavicarpa) pulp

Macoris, Mariana Serrao; Janzantti, Natalia Soares; Garruti, Deborah dos Santos; Monteiro, Magali
Fonte: Soc Brasileira Ciência Tecnologia Alimentos Publicador: Soc Brasileira Ciência Tecnologia Alimentos
Tipo: Artigo de Revista Científica Formato: 430-435
ENG
Relevância na Pesquisa
76.95%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); The volatile compositions from organic and conventional passion fruit pulps produced in Brazil were investigated. The pulps were also physicochemically characterized. The volatile compounds from the headspace of the passion fruit pulp were stripped to a Porapak Q trap for 2 hours; they were eluted with 300 mu L of dichloromethane, separated by gas chromatography/flame ionisation detection and identified through gas chromatography/mass spectrometry. Both pulps conformed to the requirements of the Brazilian legislation, indicating they were suitable to be industrialized and consumed. A total of 77 compounds were detected in the headspace of the passion fruit pulps - 60 of which were identified, comprising 91% of the total chromatogram area. The major compounds were the following: ethyl butanoate, 52% and 57% of the total relative area of the chromatogram for the organic and conventional passion fruit pulps, respectively; ethyl hexanoate, 22% and 9%, respectively; and hexyl butanoate, 2% and 5%, respectively. The aroma of the organic passion fruit pulp is mainly related to the following volatile compounds: ethyl hexanoate...

The influence of ripening stage and cultivation system on the total antioxidant activity and total phenolic compounds of yellow passion fruit pulp

Macoris, Mariana S.; De Marchi, Renata; Janzantti, Natalia S.; Monteiro, Magali
Fonte: Wiley-Blackwell Publicador: Wiley-Blackwell
Tipo: Artigo de Revista Científica Formato: 1886-1891
ENG
Relevância na Pesquisa
97.01%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); BACKGROUND: This work aimed to investigate the influence of both ripening stage and cultivation system on the total phenolic compounds (TPC) and total antioxidant activity (TAA) of passion fruit pulp. TPC extraction was optimized using a 23 central composed design. The variables were fruit pulp volume, methanol volume and extraction solution volume. TPC was determined using the FolinCiocalteu reaction, and TAA using the ABTS radical reaction. RESULTS: The conditions to extract TPC were 2 mL passion fruit pulp and 9 mL extraction solution containing 40% methanol:water (v/v). TPC values increased in the passion fruit pulp during ripening for both cultivation systems, ranging from 281.8 to 361.9 mg gallic acid L-1 (P?0.05) for the organic pulp and from 291.0 to 338.6 mg gallic acid L-1 (P?0.05) for the conventional pulp. CONCLUSION: TPC values increased during ripening for both organic and conventional passion fruit. The same was true for TAA values for conventional passion fruit. For organic passion fruit, however, TAA values were highest at the initial ripening stages. These results suggest that antioxidant compounds exert strong influence on the initial ripening stages for organic passion fruit...

Estudo da influência da proporção de um mix leite/popa da marcacujá na produção de pó obtido por três diferentes tipos de secagem

Catelam, Kelly Tafari
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Dissertação de Mestrado Formato: 119 f. : il. color.
POR
Relevância na Pesquisa
66.98%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Pós-graduação em Engenharia e Ciência de Alimentos - IBILCE; Este projeto teve como objetivo estudar a influência de diferentes processos de desidratação (secagem em leito pulso-fluidizado, atomizador – “spray dryer” e em liofilizador) de polpa de maracujá na qualidade do produto final em pó. Todos estes processos visam à obtenção do produto em pó, apresentando vantagens e desvantagens em nível de manuseio e custos. Entretanto, são escassos na literatura estudos que comparem estes processos com foco na qualidade do produto final. O leite desnatado foi utilizado para avaliar sua eficiência na substituição de parte dos aditivos comumente utilizados na produção deste tipo de produto, como, por exemplo, a maltodextrina e a goma Arábica, os quais têm como função a diminuição das dificuldades tecnológicas encontradas na secagem de sucos de frutas e outros produtos com alta quantidade de açúcar devido à higroscopicidade, termoplasticidade e capacidade de caramelização. Inicialmente, realizaram-se as análises físico-químicas da polpa de maracujá e do leite desnatado, onde foram obtidos resultados muito próximos aos da literatura, sendo que as pequenas diferenças obtidas foram atribuídas à variedade do maracujá utilizado...

Efeito da polpa de maracujá amarelo (Passiflora. edulis f. flavicarpa Deg) sobre os danos genotóxicos e nefrotóxicos imediatos induzidos pela cisplatina em ratos espontaneamente hipertensos

Konta, Eliziani Mieko
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Dissertação de Mestrado Formato: 86 f.
POR
Relevância na Pesquisa
66.88%
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Pós-graduação em Alimentos e Nutrição - FCFAR; Os antioxidantes, principalmente os encontrados na dieta, são agentes responsáveis pela inibição e redução dos danos oxidativos causados pelas espécies reativas nas células. A cisplatina (cDDP), um potente agente antineoplásico utilizado com frequência no tratamento de tumores sólidos, tem seu uso clínico limitado devido aos efeitos adversos como nefrotoxicidade, genotoxicidade e supressão da medula óssea. Como a geração de espécies reativas pode resultar em danos ao DNA pela ação destas espécies ou indiretamente via produtos de degradação da peroxidação lipídica, nosso estudo avaliou o possível efeito protetor da adição da polpa de maracujá amarelo na dieta de ratos espontaneamente hipertensos (SHR) e Wistar normotensos, contra a nefrotoxicidade e genotoxicidade induzida pela cDDP. Os resultados obtidos nas condições experimentais estabelecidas neste trabalho mostraram que a cDDP promoveu um aumento dos níveis das substâncias reativas aos ácido tiobarbitúrico, bem como decréscimo nos níveis de glutationa nos rins dos animais SHR, reforçando a hipótese que a peroxidação lipídica está relacionada com o mecanismo de nefrotoxicidade. O tratamento com doses múltiplas da polpa de maracujá amarelo não alterou os outros parâmetros da função renal no período analisado. Embora o efeito protetor da polpa de maracujá contra os danos induzidos ao DNA em células renais e hepáticas não tenha sido evidente nos resultados obtidos pelo Ensaio do Cometa...

Evaluation of the Antihypertensive Properties of Yellow Passion Fruit Pulp (Passiflora edulis Sims f. flavicarpa Deg.) in Spontaneously Hypertensive Rats

Konta, Eliziane Mieko; Almeida, Mara Ribeiro; Amaral, Catia Lira do; Castania Darin, Joana Darc; Rosso, Veridiana V. de; Mercadante, Adriana Zerlotti; Greggi Antunes, Lusania Maria; Pires Bianchi, Maria Lourdes
Fonte: Wiley-Blackwell Publicador: Wiley-Blackwell
Tipo: Artigo de Revista Científica Formato: 28-32
ENG
Relevância na Pesquisa
86.96%
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Processo FAPESP: 06/61237-4; Processo FAPESP: 05/595992-6; Various species of the genus Passiflora have been extensively used in traditional medicine as sedatives, anxiolytics, diuretics and analgesics. In the present study, after the identification and quantification of phytochemical compounds from yellow passion fruit pulp by liquid chromatography-photodiode array-mass spectrometry (HPLC-PDA-MS/MS), its antihypertensive effect was investigated on spontaneously hypertensive rats. Additionally, the renal function, evaluated by kidney/body weight, serum creatinine, proteinuria, urinary flow, reduced glutathione (GSH) levels and thiobarbituric acid-reactive substances (TBARS) and mutagenicity in bone marrow cells were assessed to evaluate the safety of passion fruit consumption. Yellow passion fruit pulp (5, 6 or 8g/kg b.w.) was administered by gavage once a day for 5 consecutive days. HLPC-PDA-MS/MS analysis revealed that yellow passion fruit pulp contains phenolic compounds, ascorbic acid, carotenoids and flavonoids. The highest dose of passion fruit pulp significantly reduced the systolic blood pressure...

Estudo do albedo de maracuja e de seu aproveitamento em barra de cereais; Study of passion fruit albedo and its industrial use in cereal bars

Fernando Cesar Akira Urbano Matsuura
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 24/02/2005 PT
Relevância na Pesquisa
66.67%
Existem consideráveis perdas de produtos agrícolas nas diversas etapas da cadeia produtiva, desde a produção no campo até o momento de consumo, passando pela elevada geração de resíduos no processamento agroindustrial de produtos animais e vegetais. Estima-se que o aproveitamento das matérias-primas vegetais não ultrapasse 80% a 85% e que os resíduos gerados possam chegar a até 30%. Além da preservação ambiental, o aproveitamento desses resíduos abrange questões econômicas e sociais. O Brasil é um grande produtor mundial de maracujá, principalmente o amarelo, e o albedo, resíduo do consumo "in natura" e do processamento, representa 12% a 32% da fruta. Os resíduos das frutas e hortaliças comumente podem conter fibras, vitaminas, minerais, substâncias fenólicas e flavonóides, entre outros, que podem ser benéficos à saúde humana, mas também podem possuir compostos tóxicos e antinutricionais que necessitam ser eliminados antes do uso. Pesquisas sobre os resíduos vegetais do processamento agroindustrial têm envolvido o tratamento dos resíduos; a extração de componentes específicos dos resíduos, como a pectina e o óleo das sementes do maracujá; e o aproveitamento integral dos resíduos em produtos alimentícios...

Bebida de maracuja natural "light" pronta para beber : formulação, produção e estudo de vida-de-prateleira.; Passion fruit juice beverage with different sweetener systems : formaulation, production and shelf life study.

Renata De Marchi
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 12/12/2006 PT
Relevância na Pesquisa
66.75%
O mercado de bebidas à base de frutas está em constante expansão. Os consumidores querem desfrutar de bebidas que vão além de apenas saciar a sede, e que ofereçam vantagens nutricionais e conveniência. Paralelamente à preferência dos consumidores por bebidas saudáveis, há uma crescente tendência ao consumo de bebidas de baixa caloria. Os consumidores estão cada vez melhor informados sobre a importância de uma dieta saudável, com menor ingestão de açúcar e gordura. Assim, o presente trabalho teve como objetivo formular, produzir, avaliar a aceitação em dois diferentes mercados consumidores ? Brasil e Estados Unidos, determinar o perfil sensorial e estudar a vida-de-prateleira de bebidas de maracujá naturais, prontas para beber, adoçadas com sacarose (referência), aspartame, sucralose, e mistura aspartame/acesulfame-K (4:1) (light), respectivamente, durante 180 dias de estocagem. A bebida de maracujá referência foi formulada utilizando-se metodologia de superfície de resposta e testes de aceitação. O conteúdo de polpa de maracujá e a concentração de sacarose, selecionados para serem usados em tal bebida foram, respectivamente, 2,5°Brix (resultantes da mistura: polpa de maracujá e água) e 10%. Para a formulação das bebidas light...

DYNAMIC AND STEADY-SHEAR RHEOLOGICAL PROPERTIES OF XANTHAN AND GUAR GUMS DISPERSED IN YELLOW PASSION FRUIT PULP (Passiflora edulis f. flavicarpa)

MORAES, I. C. F.; FASOLIN, L. H.; CUNHA, R. L.; MENEGALLI, F. C.
Fonte: BRAZILIAN SOC CHEMICAL ENG Publicador: BRAZILIAN SOC CHEMICAL ENG
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
86.71%
Yellow passion fruit pulp is unstable, presenting phase separation that can be avoided by the addition of hydrocolloids. For this purpose, xanthan and guar gum [0.3, 0.7 and 1.0% (w/w)] were added to yellow passion fruit pulp and the changes in the dynamic and steady-shear rheological behavior evaluated. Xanthan dispersions showed a more pronounced pseudoplasticity and the presence of yield stress, which was not observed in the guar gum dispersions. Cross model fitting to flow curves showed that the xanthan suspensions also had higher zero shear viscosity than the guar suspensions, and, for both gums, an increase in temperature led to lower values for this parameter. The gums showed different behavior as a function of temperature in the range of 5-35 degrees C. The activation energy of the apparent viscosity was dependent on the shear rate and gum concentration for guar, whereas for xanthan these values only varied with the concentration. The mechanical spectra were well described by the generalized Maxwell model and the xanthan dispersions showed a more elastic character than the guar dispersions, with higher values for the relaxation time. Xanthan was characterized as a weak gel, while guar presented a concentrated solution behavior. The simultaneous evaluation of temperature and concentration showed a stronger influence of the polysaccharide concentration on the apparent viscosity and the G` and G `` moduli than the variation in temperature.

Volatile compounds from organic and conventional passion fruit (Passiflora edulis F. Flavicarpa) pulp

Macoris,Mariana Serrão; Janzantti,Natália Soares; Garruti,Deborah dos Santos; Monteiro,Magali
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 EN
Relevância na Pesquisa
76.95%
The volatile compositions from organic and conventional passion fruit pulps produced in Brazil were investigated. The pulps were also physicochemically characterized. The volatile compounds from the headspace of the passion fruit pulp were stripped to a Porapak Q trap for 2 hours; they were eluted with 300 µL of dichloromethane, separated by gas chromatography/flame ionisation detection and identified through gas chromatography/mass spectrometry. Both pulps conformed to the requirements of the Brazilian legislation, indicating they were suitable to be industrialized and consumed. A total of 77 compounds were detected in the headspace of the passion fruit pulps - 60 of which were identified, comprising 91% of the total chromatogram area. The major compounds were the following: ethyl butanoate, 52% and 57% of the total relative area of the chromatogram for the organic and conventional passion fruit pulps, respectively; ethyl hexanoate, 22% and 9%, respectively; and hexyl butanoate, 2% and 5%, respectively. The aroma of the organic passion fruit pulp is mainly related to the following volatile compounds: ethyl hexanoate, methyl hexanoate, β-myrcene and D-limonene. The conventional passion fruit pulp presented methyl butanoate, butyl acetate...

Quantification of harman alkaloids in sour passion fruit pulp and seeds by a novel dual SBSE-LC/Flu (stir bar sorptive extraction-liquid chromatography with fluorescence detector) method

Pereira,Cíntia A. M.; Rodrigues,Thyago R.; Yariwake,Janete H.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2014 EN
Relevância na Pesquisa
76.56%
A method for the quantification of the alkaloids harmane and harmine in sour passion fruit (Passiflora edulis f. flavicarpa O. Degener, Passifloraceae) pulp and seeds by stir-bar sorptive extraction and high performance liquid chromatography with fluorescence detection (dual SBSE-LC/Flu) is described. The SBSE parameters were optimized using a fractional factorial design, and the dual SBSE-LC/Flu method was validated following the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) guidelines. The high sensitivity and minimal sample handling of the dual SBSE-LC/Flu method make it attractive for application in phytochemical analysis or in the food industry.

Effects of airflow induction on heat transfer and energy consumption while freezing passion fruit pulp in stacked boxes

Fonte: International Energy Agency Publicador: International Energy Agency
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
86.81%
The objectives of this work were to charac- terize the energy consumption and the heat transfer process by the determination of the convective heat transfer coefficient (h) of passion fruit pulp contained in high-density polyethylene (HDPE) boxes and frozen in two conditions: without and with airflow induction, which was achieved through the installation of obsta- cles. To determine the convective heat transfer coeffi- cients, HDPE boxes containing passion fruit pulp (contained in polyethylene bags) were interspersed with boxes containing metal tanks filled with low freezing point solutions. Three types of solutions were used: ethylene glycol, propylene glycol, and ethanol. The airflow induction under the stacks of passion fruit pulp provided higher h values than without airflow induction. The calculated average values and standard deviation were 6.340±0.87 W/m 2 °C, respectively, without air- flow induction and 8.419±1.39 W/m 2 °C with airflow induction. The average reduction of the freezing time was 25 % for the boxes located at the top and 20 % in the base of the stack. This proved that directing the airflow under the stacked product promoted more uniform and efficient heat transfer. The analysis of the electrical parameter measurements revealed an approximate de- crease of 16.7 % in energy consumption due to the reduction of the freezing time...

Thermal Conductivity Measurements and Predictive Models for Frozen Guava and Passion Fruit Pulps

Fonte: Taylor & Francis Group Publicador: Taylor & Francis Group
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
76.6%
The thermal conductivity of guava and passion fruit pulps was measured at temperatures between −30°C and their initial freezing temperature using the hot wire probe method. The results were compared with those calculated using the parallel, perpendicular, and Maxwell-Eucken models as a function of the ice fraction, and the discrepancies in the results are discussed. Exponential equations were then fit to the experimental data to determine the thermal conductivity of the pulps as a function of temperature. These equations produce mean relative errors of 8.1 and 4.0% in the values estimated for the guava and passion fruit pulp, respectively.

Dynamic and steady: shear rheological properties of xanthan and guar gums dispersed in yellow passion fruit pulp (Passiflora edulis f. flavicarpa)

MORAES, I. C. F; FASOLIN, L. H; CUNHA, R. L; MENEGALLI, F. C
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
86.71%
Yellow passion fruit pulp is unstable, presenting phase separation that can be avoided by the addition of hydrocolloids. For this purpose, xanthan and guar gum [0.3, 0.7 and 1.0% (w/w)] were added to yellow passion fruit pulp and the changes in the dynamic and steady - shear rheological behavior evaluated. Xanthan dispersions showed a more pronounced pseudoplasticity and the presence of yield stress, which was not observed in the guar gum dispersions. Cross model fitting to flow curves showed that the xanthan suspensions also had higher zero shear viscosity than the guar suspensions, and, for both gums, an increase in temperature led to lower values for this parameter. The gums showed different behavior as a function of temperature in the range of 5 - 35ºC. The activation energy of the apparent viscosity was dependent on the shear rate and gum concentration for guar, whereas for xanthan these values only varied with the concentration. The mechanical spectra were well described by the generalized Maxwell model and the xanthan dispersions showed a more elastic character than the guar dispersions, with higher values for the relaxation time. Xanthan was characterized as a weak gel, while guar presented a concentrated solution behavior. The simultaneous evaluation of temperature and concentration showed a stronger influence of the polysaccharide concentration on the apparent viscosity and the G' and G" moduli than the variation in temperature.

Effect of drying method on the adsorption isotherms and isosteric heat of passion fruit pulp powder

Pedro,Maria Angélica Marques; Telis-Romero,Javier; Telis,Vânia Regina Nicoletti
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 01/12/2010 EN
Relevância na Pesquisa
66.84%
The sorption behavior of dry products is generally affected by the drying method. The sorption isotherms are useful to determine and compare thermodynamic properties of passion fruit pulp powder processed by different drying methods. The objective of this study is to analyze the effects of different drying methods on the sorption properties of passion fruit pulp powder. Passion fruit pulp powder was dehydrated using different dryers: vacuum, spray dryer, vibro-fluidized, and freeze dryer. The moisture equilibrium data of Passion Fruit Pulp (PFP) powders with 55% of maltodextrin (MD) were determined at 20, 30, 40 and 50 ºC. The behavior of the curves was type III, according to Brunauer's classification, and the GAB model was fitted to the experimental equilibrium data. The equilibrium moisture contents of the samples were little affected by temperature variation. The spray dryer provides a dry product with higher adsorption capacity than that of the other methods. The vibro-fluidized bed drying showed higher adsorption capacity than that of vacuum and freeze drying. The vacuum and freeze drying presented the same adsorption capacity. The isosteric heats of sorption were found to decrease with increasing moisture content. Considering the effect of drying methods...

Dynamic and steady: shear rheological properties of xanthan and guar gums dispersed in yellow passion fruit pulp (Passiflora edulis f. flavicarpa)

Moraes,I. C. F; Fasolin,L. H; Cunha,R. L; Menegalli,F. C
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2011 EN
Relevância na Pesquisa
86.71%
Yellow passion fruit pulp is unstable, presenting phase separation that can be avoided by the addition of hydrocolloids. For this purpose, xanthan and guar gum [0.3, 0.7 and 1.0% (w/w)] were added to yellow passion fruit pulp and the changes in the dynamic and steady - shear rheological behavior evaluated. Xanthan dispersions showed a more pronounced pseudoplasticity and the presence of yield stress, which was not observed in the guar gum dispersions. Cross model fitting to flow curves showed that the xanthan suspensions also had higher zero shear viscosity than the guar suspensions, and, for both gums, an increase in temperature led to lower values for this parameter. The gums showed different behavior as a function of temperature in the range of 5 - 35ºC. The activation energy of the apparent viscosity was dependent on the shear rate and gum concentration for guar, whereas for xanthan these values only varied with the concentration. The mechanical spectra were well described by the generalized Maxwell model and the xanthan dispersions showed a more elastic character than the guar dispersions, with higher values for the relaxation time. Xanthan was characterized as a weak gel, while guar presented a concentrated solution behavior. The simultaneous evaluation of temperature and concentration showed a stronger influence of the polysaccharide concentration on the apparent viscosity and the G' and G" moduli than the variation in temperature.

Water adsorption isotherms and isosteric sorption heat of spray-dried and freeze-dried dehydrated passion fruit pulp with additives and skimmed milk

Catelam,Kelly Tafari; Trindade,Carmen Sílvia Fávaro; Romero,Javier Telis
Fonte: Editora da Universidade Federal de Lavras Publicador: Editora da Universidade Federal de Lavras
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2011 EN
Relevância na Pesquisa
66.76%
Moisture equilibrium data of passion fruit pulp powders with maltodextrin and gum arabic were obtained by two different drying methods (spray drying and freeze drying) and determined at 20, 30, 40 and 50º C. Skimmed milk was used to substitute part of these additives in the samples. One formulation using passion fruit pulp/maltodextrin/skimmed milk (PMS) was prepared, and another using passion fruit pulp/gum arabic/skimmed milk (PGS). The behavior of curves was type III, according to Brunauer's classification. GAB models were fitted to experimental equilibrium data. The parameters obtained from GAB models was affected by the presence of additives. The behavior of the sorption isotherms for different temperatures are similar, noting only a small effect of temperature. There were little differences between both drying methods and additives used in relation to equilibrium moisture content. The parameters obtained with the addition of the skimmed milk were considered satisfactory (Xm values ranged from 0,04084 to 0,06488 in dry basis), demonstrating that it is an effective and cheap alternative for regular additives. A progressive increase in the heat of sorption in relation to decreasing moisture content was observed and the heat of sorption values of different samples are all similar...