| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 3.95 MB | Adobe PDF |
Authors
Advisor(s)
Abstract(s)
Este trabalho teve como objetivo o uso de técnicas de alta pressão, nomeadamente a extração supercrítica e extração com água líquida quente em condições alcalinas para valorização da coffee silverskin, um resíduo da torrefação e descafeinação do café. Este trabalho foi desenvolvido no âmbito de programa Erasmus+ na Hamburg University of Technology. A recuperação de gorduras usando dióxido de carbono supercrítico foi realizada em nove combinações de diferentes pressões e temperaturas usando como biomassa pellets de coffee silverskin esmagadas com um almofariz e um pilão: 350, 400 e 450 bar e 40, 50 e 60 ºC. O rendimento mais alto foi de 3.34% a 450 bar e 60ºC, enquanto que o mais baixo foi de 2.33% a 350 bar e 40 ºC. O efeito da dimensão das partículas também foi estudado. Quatro tamanhos diferentes de partículas de coffee silverskin (22, 79, 379 e 1057 µm) sofreram extração a 450 bar e 60ºC e a sua extração foi modelada com o software “BatchSFE”, desenvolvido pelo Institute of Thermal Separation Processes da Hamburg University of Technology. Para as três frações mais pequenas obtiveram-se rendimentos semelhantes (4.20% para 22 µm, 4.47% para 79 µm e 4.43% para 379 µm). Já a fração maior obteve um rendimento de 3.11%. A extração de proteínas através de água líquida quente foi estudada a 120 ºC e 20 bar, durante um período de 30 minutos usando concentrações de soluções de NaOH de 0, 0.01, 0.03 e 0.05 mol/L, e pellets de coffee silverkin. A adição de NaOH promoveu a extração dos aminoácidos. Sem adição de NaOH o rendimento foi de 2.0%, enquanto que a uma concentração de NaOH de 0.05 mol/L o rendimento foi de 5.6%. Para identificar o efeito de uma extração supercrítica antes de uma extração de água quente líquida, pellets previamente tratadas com dióxido de carbono supercrítico foram submetidas a um tratamento de água quente líquida a 120ºC durante 30 minutos com uma concentração de NaOH de 0.05 mol/L. Nestas condições o rendimento foi de 4.0%. O efeito da temperatura e o tempo de residência também foi estudado com pellets extraídas a 90, 105 e 120 ºC e 30 e 60 minutos. O rendimento mais elevado foi a 120 ºC durante 60 minutos (6.3%) e o mais baixo foi obtido a 90 ºC durante 60 minutos (1.4%). Os seguintes aminoácidos foram identificados: alanina, arginina, ácido aspártico, acido glutâmico, glicina, histidina, iso-leucina, leucina, lisina, metionina, fenilamina, serina treonina, tirosina e valina.
This work focused on the usage of high-pressure technologies, such as supercritical fluid extraction and liquid hot water treatment in alkaline conditions for the recovery of lipids and proteins in coffee silverskin, a by-product of coffee roasting and decaffeination. The work was developed within the scope of Erasmus+ program at the Hamburg University of Technology. The extraction of lipids by means of supercritical carbon dioxide was studied using nine combinations of different pressures and temperatures and coffee silverskin pellets crushed with a mortar and a pestle as raw materials: 350, 400 and 450 bar, and 40, 50 and 60ºC. The highest yield was 3.34%, and it was obtained at 450 bar and 60ºC. The lowest yield was 2.33% and it was obtained at 350 bar and 40ºC. Furthermore, the impact of particle size was also studied. Four different particle sizes of coffee silverskin powder (22, 79, 379 and 1057 µm) were extracted at 450 bar and 60ºC, and modeled with the software “BatchSFE”, developed by the Institute of Thermal Separation Processes of the Hamburg University of Technology. The three smaller particle ranges obtained similar yields (4.20% for 22 µm, 4.47% for 79 µm and 4.43% for 379 µm), whereas the biggest fraction obtained a yield of 3.11%. The extraction of proteins by means of liquid hot water pretreatment was studied at 120 ºC and 20 bar with a residence time of 30 minutes using concentrations of NaOH of 0, 0.01, 0.03 and 0.05 mol/L and coffee silverskin pellets. The addition of NaOH improved the extraction of amino acids. At a concentration of NaOH of 0 mol/L the yield obtained was 2.0%, while at a concentration of 0.5 mol/L the yield was 5.6%. To observe the effect of supercritical fluid extraction on the protein recovery, pellets extracted beforehand were submitted at a liquid hot water at 120ºC for 30 minutes, at a concentration of NaOH of 0.05 mol/. The yield obtained was 4.0%. The effect of residence time and temperature was studied on the extracted pellets at 90, 105 and 120 ºC and 30 and 60 minutes, using a concentration of NaOH of 0.05 mol/L. The highest yield was 6.3%, obtained at 120 ºC and 60 minutes. The lowest yield was 1.4% at 90ºC and 60 minutes. The following amino acids were detected on coffee silverskin: alanine, arginine, aspartic acid, glutamic acid, glycine, histidine, iso-leucine, leucine, lysine, methionine, phenylamine, serine, threonine, tyrosine and valine.
This work focused on the usage of high-pressure technologies, such as supercritical fluid extraction and liquid hot water treatment in alkaline conditions for the recovery of lipids and proteins in coffee silverskin, a by-product of coffee roasting and decaffeination. The work was developed within the scope of Erasmus+ program at the Hamburg University of Technology. The extraction of lipids by means of supercritical carbon dioxide was studied using nine combinations of different pressures and temperatures and coffee silverskin pellets crushed with a mortar and a pestle as raw materials: 350, 400 and 450 bar, and 40, 50 and 60ºC. The highest yield was 3.34%, and it was obtained at 450 bar and 60ºC. The lowest yield was 2.33% and it was obtained at 350 bar and 40ºC. Furthermore, the impact of particle size was also studied. Four different particle sizes of coffee silverskin powder (22, 79, 379 and 1057 µm) were extracted at 450 bar and 60ºC, and modeled with the software “BatchSFE”, developed by the Institute of Thermal Separation Processes of the Hamburg University of Technology. The three smaller particle ranges obtained similar yields (4.20% for 22 µm, 4.47% for 79 µm and 4.43% for 379 µm), whereas the biggest fraction obtained a yield of 3.11%. The extraction of proteins by means of liquid hot water pretreatment was studied at 120 ºC and 20 bar with a residence time of 30 minutes using concentrations of NaOH of 0, 0.01, 0.03 and 0.05 mol/L and coffee silverskin pellets. The addition of NaOH improved the extraction of amino acids. At a concentration of NaOH of 0 mol/L the yield obtained was 2.0%, while at a concentration of 0.5 mol/L the yield was 5.6%. To observe the effect of supercritical fluid extraction on the protein recovery, pellets extracted beforehand were submitted at a liquid hot water at 120ºC for 30 minutes, at a concentration of NaOH of 0.05 mol/. The yield obtained was 4.0%. The effect of residence time and temperature was studied on the extracted pellets at 90, 105 and 120 ºC and 30 and 60 minutes, using a concentration of NaOH of 0.05 mol/L. The highest yield was 6.3%, obtained at 120 ºC and 60 minutes. The lowest yield was 1.4% at 90ºC and 60 minutes. The following amino acids were detected on coffee silverskin: alanine, arginine, aspartic acid, glutamic acid, glycine, histidine, iso-leucine, leucine, lysine, methionine, phenylamine, serine, threonine, tyrosine and valine.
Description
Keywords
Coffee silverskin Extração supercrítica Dióxido de carbono supercrítico Pré-tratamento com água quente líquida Hidrolise alcalina Supercritical fluid extraction Supercritical carbon dioxide Liquid hot water pretreatment Alkaline hydrolysis