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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Desenvolvimento de um mÃtodo de despeliculamento de amÃndoas de castanha de caju tipo âdurÃoâ com vapores Ãcidos e salino / Development the a method the peeling the kernels the cashew nut called "durao" steams from acidic and saline.

Karla IdelÃa Aires Machado 19 July 2013 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Um dos maiores problemas atuais da indÃstria de beneficiamento de castanha de caju, sÃo as amÃndoas que necessitam de re-despeliculagem, as amÃndoas do tipo âdurÃoâ, despeliculadas manualmente, ou com vapor convencional, tendo como inconvenientes a baixa produtividade de raspagem e o escurecimento das amÃndoas, fatores depreciativos de preÃo. Para solucionar esse problema, inicialmente foram realizados em nÃvel de laboratÃrio, ensaios de tratamento de amÃndoas despeliculadas e com pelÃculas de diÃmetro mÃdio à = 1,68 mm, com vapores provenientes de soluÃÃes de Ãcido tartÃrico (1%; 2% e 3%), Ãcido mÃlico (1%; 3% e 5%), cloreto de potÃssio (1%, 2% e 3%) e Ãgua nos tempos de exposiÃÃo de 1,2, 3, 4 e 5 minutos. Foram quantificados nos condensados dos vapores, provenientes do tratamento da pelÃcula, os compostos fenÃlicos totais e pigmentos hidrossolÃveis. Os compostos fenÃlicos totais tambÃm foram quantificados nos vapores apÃs os tratamentos das amÃndoas despeliculadas. Nas amÃndoas despeliculadas foram determinados a concentraÃÃo de hidroximetilfurfural (HMF) e a cor instrumental. Neste estudo, alÃm de quantificar os constituintes jà citados, foi de extrema importÃncia o entendimento acerca da forma como ocorre o escurecimento na superfÃcie das amÃndoas, via reaÃÃo de Maillard e pela interaÃÃo dos pigmentos extraÃdos com esses vapores. Os resultados mostraram que os menores teores de pigmentos solÃveis, fenÃlicos totais extraÃdos da pelÃcula e a menor formaÃÃo de hidroximetilfurfural nas amÃndoas ocorreram nos tratamentos com Ãcido tartÃrico 1,0% - 1,0 minuto; Ãcido mÃlico - 1% - 1,0 minuto; cloreto de potÃssio 2,0% - 1 minuto e Ãgua - 1,0 minuto. Foi avaliado tambÃm o despeliculamento e a quebra em escala industrial nas amÃndoas durÃo com pelÃcula aplicando esses vapores citados, nos tempos e concentraÃÃes mencionados, mostrando os seguintes valores para as porcentagens de despeliculagem e quebra, respectivamente: Ãcido mÃlico: 50,24 - 28,37; Ãcido tartÃrico: 56,78 - 20,99; cloreto de potÃssio: 56,52 - 23,15 e Ãgua: 50,43 - 24,12. A anÃlise colorimÃtrica das amÃndoas tratadas com vapor de Ãcido tartÃrico a 1% - 1 min. mostrou que esta fonte de vapor, foi a que apresentou melhores resultados em todos os parÃmetros (L*, a* e b*), quando comparadas as amÃndoas padrÃo tipo 01 tratadas com vapor de Ãgua. Os resultados mostraram ainda que à mais vantajoso usar vapor de Ãcido tartÃrico em vez de vapor de Ãgua para aumentar o rendimento de despeliculagem e reduzir a quebra das amÃndoas de castanha de caju tipo âdurÃoâ. / One of the biggest challenges that faces the cashew nut processing industries today, is the kernels that needs to peel again, called durao kernels, manually peeled- with a low peeling yield or peeled with conventional water steam - which causes a noticeable browning, decreasing its commercial value. To solve this problem, were performed initially on a laboratory scale, peeled kernels and skin (à = 1,68 mm) from kernels were treated with steams from tartaric acid 1,0;2,0;3,0% ; malic acid 1,0;3,0;5,0 % ; potassium chloride 1,0;2,0 3,0% and water during 1,2,3,4 and 5 minutes. Was measured the condensed steam, from treatment of the skin, total phenolics and water soluble pigments. The total phenolics were also measured in the steams after treatment of peeled kernels. In kernel peeled, concentration hydroxymethylfurfural (HMF) and instrumental color, was determined. In this study, in addition to measuring the constituents already mentioned, was extremely important to the understanding of how browning occurs on the surface of kernels, the Maillard reaction and the interactions of the extracted pigments with their steams. The results showed that the lowest concentration of soluble pigments, total phenolics extracted from the skin and less formation of hydroxymethylfurfural in kernels occurred in treatment with tartaric acid 1,0% - 1,0 minute; malic acid 1,0% - 1,0 minute; potassium chloride 2,0% - 1,0 minute and water - 1,0 minute. The peeled and breaking on an industrial scale in kernels durao with skin applying these steams cited in times and concentrations mentioned, showing the following values for the percentages of peeling and breaking, was determined respectively - malic acid: 50,24 - 28,37; tartaric acid: 56,78 - 20,99; potassium chloride: 56,52 - 23,15 and water: 50,43 - 24,12. From the peeled kernel colorimetric analysis (L*, a*, b*) after treatments with the four steams in the times above mentioned, tartaric acid 1,0% - 1,0 minute showed the best values when compared with the colour parameter of the kernel exportation 01- standard. The results still showed that is more profitable to use tartaric acid steam instead of water steam to increase peeling yield and reduce kernel durao breaking.

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