Condutividade e difusividade térmica do figo (Ficus carica L.) "Roxo de Valinhos"

Dussán-Sarria, Saúl; Honório, Sylvio Luis

doi:10.1590/s0100-69162004000100021

Cited by 7 publications

(5 citation statements)

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“…Also, for other fruit as fig (Sarria and Honório, 2004) and coconut pulp (Etuk et al, 2005) the thermal diffusivity is in the range of 10 -3-cm 2 /s. The Table 1 shows the time dependence of the SS, firmness, pH and TTA in the fruit.…”

Section: Resultsmentioning

confidence: 99%

“…The softening of papaya pulp is attributed to the activity of cell wall-degrading enzymes, such as polygalacturonase [PG; EC 3.2.1.67] (Chan et al, 1981;Lazan et al, 1995), pectinmetylesterase [PME; EC 3.1.1.11], β-galactosidase [GAL; EC 3.2.1.23] (Lazan et al, 1995), and xylanase [XYL; EC 3.2.1.32] (Paull and Chen, 1983). The action of such enzymes decomposes the central lamellae of the cellular wall, reducing the cell-to-cell binding and thus the pulp tissues become soft (Smith et al, 2003). The rupture of cell lamellae that results in a flaccid tissue, promotes a discontinuity in the linking cell to cell (thermal coupling) that modifies the property of thermal diffusion of mesocarp of papaya fruit.…”

Section: Resultsmentioning

confidence: 99%

“…The determination of the thermal physics properties of the fruit pulp plays an important role (Sarria and Honório, 2004;Wang et al, 2001) for optimizing the thermal treatment, aiming the reduction of stress in the fruit. Among thermal physics properties, the thermal diffusivity is important mainly because it is directly related to the thermal conductivity of the sample.…”

Section: Introductionmentioning

confidence: 99%

“…During maturation, physical and biochemical changes, involving respectively texture changes (Smith et al, 2003) and biosynthesis of carbohydrates (as well as, their breakdown) would be responsible for general changes on the thermal properties of the fruit tissues.…”

Section: Introductionmentioning

confidence: 99%

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Determination of thermal diffusivity in papaya pulp as a function of maturation stage

Corrêa¹,

Souza²,

Pereira³

et al. 2008

Rev. Bras. Frutic.

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-In order to determine the penetration of the thermal wave in the papaya fruit pulp (Carica papaya L.), cv. Golden, thermal diffusivity of the pulp was obtained measuring temperature at four different depths. Measurements were carried out initially with the fruit on the first stage of maturity. The changes of the thermal diffusivity were expressed as a function of ripening. A temporal decrease of the thermal diffusivity was observed. Chemical (pH, soluble solids and total titratable acidity) and physical (pulp firmness) properties were measured as well and the results were compared to the thermal diffusivity change. Index terms: Carica papaya L.; thermal wavelength; quality parameters. DETERMINAÇÃO DA DIFUSIVIDADE TÉRMICA DA POLPA DE MAMÃO EM FUNÇÃO DO ESTÁDIO DE MATURAÇÃORESUMO-Para determinar a penetração da onda térmica na polpa do fruto do mamoeiro (Carica papaya L.), cv. Golden, a difusividade térmica foi obtida medindo a temperatura da polpa em quatro diferentes profundidades. As medidas foram realizadas inicialmente no estádio I de maturação do fruto, e as variações da difusividade térmica foram expressas em função do amadurecimento. Foi observada a diminuição da difusividade térmica no tempo. Propriedades químicas (pH, sólidos solúveis e acidez titulável) e física (firmeza da polpa) também foram determinadas, e os resultados, comparados com as variações da difusividade térmica. Termos para indexação: Carica papaya L.; comprimento de onda térmica; parâmetros de qualidade.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Determination of thermal diffusivity in papaya pulp as a function of maturation stage

Corrêa¹,

Souza²,

Pereira³

et al. 2008

Rev. Bras. Frutic.

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“…8. The experimental thermal conductivity of the milk was corrected using this factor (SARRIA; HONORIO, 2004). (8) The value of for the sucrose solution was obtained by Ashrae (2002) at temperatures of 0, 20, 50 and 80°C.…”

Section: (7)mentioning

confidence: 99%

Thermal conductivity of milk with different levels of moisture and fat: experimental measures and prediction models

et al. 2013

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Thermal conductivity is one of the most influential properties affecting the pasteurization of milk and is highly dependent on the milk composition and the temperature used in the process. The purpose of this work was to model the thermal conductivity of milk with a moisture content from 88.3 to 91.2% and fat content from 0 to 3.5% from 20 to 80°C. For milk with a lower moisture percentage, the experimental conductivity ranged from 0.560 to 0.637 W m -1 K -1 , and for those samples with a higher moisture percentage, conductivity ranged from 0.584 to 0.652 W m -1 K -1 . Three theoretical predictive models, series, parallel and Maxwell-Eucken, which use food composition data, were tested, and polynomial functions were fit to model the behavior of this property as a function of moisture and fat content. The results showed that thermal conductivity values are linearly dependent on the moisture content and inversely dependent on the fat content. Among the models, the parallel model was the best fit to the experimental data with a maximum error of 2.7%. Key words: Thermal conductivity, structural models, hot wire probe, moisture, fat, milk ResumoA condutividade térmica é uma das propriedades mais influentes durante a pasteurização, sendo altamente dependente da composição do leite e da temperatura utilizada no processo. Este trabalho objetivou modelar a condutividade em uma faixa de temperatura de 20 a 80°C para leites com teores de umidade de 88,3 a 91,2% e teores de gordura entre 0 e 3,5%. Para o leite com menor porcentagem de umidade, a condutividade variou de 0,560 a 0,637 W m -1 K -1 e para aquele com maior teor de umidade a condutividade esteve entre 0,584 a 0,652 W m -1 K -1 . Três modelos teóricos de predição, série, paralelo e de Maxwell-Eucken, os quais utilizam dados da composição do alimento foram testados e funções polinomiais foram ajustadas para modelar o comportamento desta propriedade em função dos teores de umidade e gordura do leite. Os resultados mostraram que os valores da condutividade térmica são linearmente dependentes do teor de umidade e inversamente dependentes dos teores de gordura. Entre os modelos testados, o modelo Paralelo foi o que melhor se ajustou aos dados experimentais com erro máximo de 2,7%.

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Precooling parameters of ‘Roxo de Valinhos’ figs (Ficus caricaL.) packed in a carton box

Dussán-Sarria¹,

Honório

Nogueira³

2006

Fruits

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Precooling parameters of 'Roxo de Valinhos' figs (Ficus carica L.) packed in a carton box. Abstract-Introduction. Figs of the variety 'Roxo de Valinhos' are currently cooled in a cold room at a temperature between (1 and 3)°C, and it is unknown how long it takes to cool the fruits to that temperature. The work was based on the need to determine the parameters of forced-air precooling of figs packed in a carton box used for exportation and commercialization in São Paulo State, Brazil. Materials and methods. The fruits were harvested at the harvest rami stage (3/4 of maturity) and at size "type 8", corresponding to eight fruits per box, making up a total of 24 fruits per package. Forty-eight packages were utilized, 24 on each side to form a Californian tunnel. The airflow was 2.8 L•s-1 per kg of product, with an average velocity of the air of 2.0 m•s-1. The initial interior temperature of the fruits was 20°C and the final temperature was 1°C. The evolution of the fig interior temperature was registered. Results. The cooling curve was drawn and the exponential analytical model to predict the precooling parameters was made based on the experimental data. The cooling curve of fig showed a typical behavior; the average fruit temperature during precooling presented a rapid fall at the beginning of the cooling, and slowly declined when it was close to the final temperature. Conclusion. The cooling time was 110 min, the cooling coefficient was 0.0344 min-1 , the Biot number was 1.3 and the convective heat transference coefficient was 23.8 °C•W-1 •m-2. Brazil / Ficus carica / fruits / packaging / cold storage / air flow / refrigeration Paramètres de préréfrigération de figues (Ficus carica L.) 'Roxo de Valinhos' emballées en boîte de carton. Résumé-Introduction. Les figues de la variété 'Roxo de Valinhos' sont actuellement refroidies en chambre froide à une température comprise entre (1 et 3)°C, et le temps nécessaire à leur refroidissement jusqu'à cette température est inconnu. Nos travaux ont été basés sur la nécessité de déterminer les paramètres de la préréfrigération par air forcé de la figue emballée en boîte de carton, telle qu'utilisée pour l'exportation et la commercialisation dans l'état de São Paulo, Brésil. Matériel et méthodes. Les fruits ont été récoltés au stade « rami » (3/4 de maturité) et au calibre « type 8 » correspondant à huit fruits par boîte. Nous avons procédé au groupement de 24 fruits par emballage. Quarante huit emballages ont été utilisés, 24 d'entre eux ont été répartis de chaque côté d'une allée pour former un tunnel californien. La circulation d'air a été de 2.8 L•s-1 par kg de produit, avec une vitesse d'air moyenne de 2.0 m•s-1. La température intérieure initiale des fruits a été de 20°C et la température finale a été de 1°C. L'évolution de la température intérieure des figues a été enregistrée. Résultats. Les données expérimentales ont permis de tracer la courbe de refroidissement et de définir les paramètres de préréfrigération à partir d'un modèle analytique exponentiel. La courbe de re...

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Condutividade e difusividade térmica do figo (Ficus carica L.) "Roxo de Valinhos"

Cited by 7 publications

References 5 publications

Determination of thermal diffusivity in papaya pulp as a function of maturation stage

Determination of thermal diffusivity in papaya pulp as a function of maturation stage

Thermal conductivity of milk with different levels of moisture and fat: experimental measures and prediction models

Precooling parameters of ‘Roxo de Valinhos’ figs (Ficus caricaL.) packed in a carton box

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