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Etudo preliminar de caracterizacao física e química de graos defeituosos de café (PVA) antes e após a torra

by Mendonca, J.C.F; Franca, A.S; Oliveira, L.S. de; Corréa, P.C.
Publisher: 2003ISSN: 0100-3518.Subject(s): CAFE VERDE | GRANOS TOSTADOS | GRANOS NEGROS | COFFEA ARABICA | FRUTO | PROPIEDADES FISICOQUIMICAS | CALIDAD | BRASIL | COFFEA ARABICA | FRUIT | CHEMICOPHYSICAL PROPERTIES | QUALITY | BRAZIL | COFFEA ARABICA | FRUIT | PROPRIETE PHYSICOCHIMIQUE | QUALITE | BRESIL In: Revista Brasileira de Armazenamento (Brasil) (Especial Café - no.7) p. 44-49Summary: The objective of the present work was to carry out a preliminary evaluation of the physical and chemical characteristics of detective coffee beans. The physical and chemical attributes evaluated were bean volume and apparent density, bulk density, color parameters and caffeine, 5-caffeoyilquinic acid and trigonelline contents. Regarding crude beans, it was observed that black beans presented lower values for bean volume and density than those for the immature, for the brown, and for the mixture of all these types of defective beans (herein designated PVA mixture). Upon roasting of the beans, no differences in the physical attributes were observed among the types of defective beans studied. Black beans presented lower values for luminosity and chroma than the other types of defective beans. No differences were observed in the measured hue values for all types of defective beans after grinding. There were no differences in caffeine content to all types of defective beans, prior to and after roasting. Similar behavior was observed for trigonelline content in relation to the crude defective and non-defective beans. Trigonelline contents diminished with roasting, with reduction being more accentuated for immature beans. Regarding the 5-caffeoyilquinic acid content, black beans presented lower values than the other types, and, upon roasting, the mixture of black and brown beans presented lower values than the PVA mixtureSummary: Este trabalho teve como objetivo geral efetuar uma avaliacao preliminar de caracterizacao física e química de graos de café defeituosos (preto, verde e ardido). As características avaliadas foram volume, massa específica aparente e granular, parametros de cor e concentracoes de cafeína, trigonelina e ácido 5-cafeoilquínico (5-ACQ). Em relacao aos graos crus, observou-se que os graos pretos apresentaram valores de volume e massa específica inferiores aos obtidos para os graos verdes, ardidos e mistura de graos pretos, verdes e ardidos (mistura PVA). Após a torra, nao foram observadas diferencas nesses parametros para os tipos de defeitos considerados. Os graos pretos inteiros apresentaram valores de luminosidade e saturacao inferiores aos demais. Nao foram observadas diferencas de tonalidade entre os tipos de graos defeituosos após a moagem nem foram detectadas diferencas nas concentracoes de cafeína entre os graos os pretos, verdes, ardidos e mistura PVA, antes e após a torra. Comportamento similar foi observado para a trigonelina em relacao aos graos crus. A concentracao de trigonelina diminuiu após a torra, sendo essa diminuicao mais acentuada para os graos verdes. Em relacao ao 5-ACQ, obteve-se uma concentracao inferior desse composto para os graos pretos crus. Após a torra, a mistura preto/ardido apresentou menor concentracao daquele composto do que a mistura PVA.
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The objective of the present work was to carry out a preliminary evaluation of the physical and chemical characteristics of detective coffee beans. The physical and chemical attributes evaluated were bean volume and apparent density, bulk density, color parameters and caffeine, 5-caffeoyilquinic acid and trigonelline contents. Regarding crude beans, it was observed that black beans presented lower values for bean volume and density than those for the immature, for the brown, and for the mixture of all these types of defective beans (herein designated PVA mixture). Upon roasting of the beans, no differences in the physical attributes were observed among the types of defective beans studied. Black beans presented lower values for luminosity and chroma than the other types of defective beans. No differences were observed in the measured hue values for all types of defective beans after grinding. There were no differences in caffeine content to all types of defective beans, prior to and after roasting. Similar behavior was observed for trigonelline content in relation to the crude defective and non-defective beans. Trigonelline contents diminished with roasting, with reduction being more accentuated for immature beans. Regarding the 5-caffeoyilquinic acid content, black beans presented lower values than the other types, and, upon roasting, the mixture of black and brown beans presented lower values than the PVA mixture

Este trabalho teve como objetivo geral efetuar uma avaliacao preliminar de caracterizacao física e química de graos de café defeituosos (preto, verde e ardido). As características avaliadas foram volume, massa específica aparente e granular, parametros de cor e concentracoes de cafeína, trigonelina e ácido 5-cafeoilquínico (5-ACQ). Em relacao aos graos crus, observou-se que os graos pretos apresentaram valores de volume e massa específica inferiores aos obtidos para os graos verdes, ardidos e mistura de graos pretos, verdes e ardidos (mistura PVA). Após a torra, nao foram observadas diferencas nesses parametros para os tipos de defeitos considerados. Os graos pretos inteiros apresentaram valores de luminosidade e saturacao inferiores aos demais. Nao foram observadas diferencas de tonalidade entre os tipos de graos defeituosos após a moagem nem foram detectadas diferencas nas concentracoes de cafeína entre os graos os pretos, verdes, ardidos e mistura PVA, antes e após a torra. Comportamento similar foi observado para a trigonelina em relacao aos graos crus. A concentracao de trigonelina diminuiu após a torra, sendo essa diminuicao mais acentuada para os graos verdes. Em relacao ao 5-ACQ, obteve-se uma concentracao inferior desse composto para os graos pretos crus. Após a torra, a mistura preto/ardido apresentou menor concentracao daquele composto do que a mistura PVA.

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