Biblioteca do Café
URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/1
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Item Perfil de ácidos orgânicos e ácidos graxos durante a secagem de café arábica(Universidade Federal de Lavras, 2018-12-07) Calderón, Renso Alfredo Aragón; Borém, Flávio Meira; Andrade, Ednilton Tavares deA interação dos fatores variedade, solo, altitude, fase de exposição, manejo, processamento, secagem, armazenamento, torra e preparo, são os responsáveis das características de complexidade obtidas na bebida de café especial. Diferentes pesquisas avaliaram as diferenças químicas de cafés com e sem a presença de parte do pericarpo durante o processamento. No entanto, a maioria foram feitas principalmente no grão cru ou sem controle de todos os outros fatores durante o processo. Acredita-se que é possível estabelecer algum ponto durante a secagem, no qual se consiga detectar onde ocorrem as diferenças da composição química entre os cafés naturais e descascados e quais compostos químicos predominam. Neste estudo amostras de café Coffea arabica L., variedade Catuaí Amarelo, procedentes de um único lote, foram coletadas com procedimentos adequados para produção de cafés especiais e submetidas simultaneamente a secagem em secador de camada fixa de convecção forçada. Foram estabelecidas amostras com presença do fruto intacto (café natural) e amostras com a remoção do exocarpo e mesocarpo (café desmucilado). Durante a secagem, foram retiradas amostras com teores de água 53±2%, 36±2%, 19±2% e 11±1% (b.u.), para análises do perfil de ácidos orgânicos por cromatografia líquida HPLC, perfil de ácidos graxos por cromatografia gasosa GC-MS e análise de compostos voláteis no grão de café torrado por GC-MS. Para os ácidos orgânicos e os ácidos graxos foi feito um desenho fatorial inteiramente casualisado DIC, para quatro teores de água (%b.u.), dois tipos de processamento (via seca e úmida), com três repetições. O perfil de ácidos orgânicos e graxos foi analisado por teste de comparação de média Scott-Knott (p<0.05) e PCA. Os compostos voláteis foram analisados com PLS-DA. A análise sensorial foi feita com uso da metodologia da SCA. O perfil de ácidos orgânicos mostrou que durante a fase de secagem entre 36±2% e 19±2% (b.u.) ocorre uma diminuição do conteúdo de ácido cítrico, succínico e acético para os dois tipos de processamento. O conteúdo de ácido quínico depende da interação entre o processamento e o teor de água, diminuindo na fase entre 36±2% e 19±2% (b.u.) para o café natural, e no café desmucilado se mantém sem alterações durante a secagem. Os ácidos graxos variam dependendo do teor de água para cada processamento, mas no final da secagem o café natural e desmucilado apresentam valores semelhantes. Foram identificados compostos voláteis predominantes no café natural: ácido acético, éster etílico, 2-metil butanal, 3-metil butanal, 2,5-dimetil pirazina, 2,3-dimetil pirazina, sendo que o perfil sensorial da bebida de café natural foi diferente do desmucilado.Item Discriminação entre estádios de maturação e tipos de processamento de pós-colheita de cafés arábica por microextração em fase sólida e análise de componentes principais(Sociedade Brasileira de Química, 2011) Arruda, Neusa P.; Hovell, Ana M. C.; Rezende, Claudia M.; Freitas, Suely P.; Couri, Sonia; Bizzo, Humberto R.A fruit chemical composition reflects its maturation stage. For coffee, it is also the reflex of the post harvesting processing type, dry, semi-wet and wet. The object of this work was to verify if headspace solid phase microextraction coupled to gas chromatography (HS-SPME-GC) could be used to discriminate between samples harvested in different maturation stages and treated by different processes. With application of principal component analysis to the area of 117 compounds extracted by SPME, using divinylbenzene/Carboxen/polydimethylsiloxane fiber, it was possible to discriminate, in the roasted and ground coffee, the maturity stage and processing type used.Item Influência do processamento e da torrefação sobre a atividade antioxidante do café (Coffea arabica)(Sociedade Brasileira de Química, 2007) Santos, Marcelo Henrique dos; Batista, Bruno Lemos; Duarte, Stella Maris da Silveira; Abreu, Celeste Maria Patto de; Gouvêa, Cibele Marli Cação PaivaThe aim of this work is to evaluate the influence of processing (semi-dry and dry) and roasting (light, medium and dark) on the antioxidant activity of coffee brews, using tests to determine the reducing power and the DPPH scavenging, Fe+2 chelating and lipid peroxidation inhibition activities. All of the coffee brews presented concentration-dependent antioxidant activity. The light coffee samples presented the higher reducing power and DPPH scavenging activity. Its ion chelating capacity was similar to the medium samples, but was less than the green coffee chelating capacity. The semi-dry processing was more efficient than the dry processing only for the reducing power. All of the samples presented high lipid peroxidation inhibition activity. Based on the results the degree of coffee roasting seems to be more important than the processing to determine the antioxidant activity of brews.Item Effect of the postharvest processing method on the biochemical composition and sensory analysis of arabica coffee(Associação Brasileira de Engenharia Agrícola, 2020) Rodriguez, Yeison F. B.; Guzman, Nelson G.; Hernandez, Joel G.The objective of this work was to study the influence of two postharvest processing methods on the biochemical composition and sensory analysis of a Colombian specialty coffee. For this purpose, coffee beans (Coffea arabica) of the Castillo variety were collected and processed using the wet and semi-dry methods, and the drying process was conducted in a sun drier prototype with a plastic parabolic cover, with a maximum drying air temperature of 50 °C; green coffee beans were managed according to the oficial Specialty Coffee Association cupping protocol and roasted to a medium and dark degree. Physicochemical determinations (pH, color, titratable acidity, caffeine content, and chlorogenic acid quantification) in green coffee and roasted coffee beans were performed; the sensory analysis was performed by a panel of trained tasters. The wet and semi-dry processing methods resulted in differences in color parameters, pH values, and caffeine content. However, the titratable acidity, chlorogenic acid, and sensory evaluation did not have any difference; therefore, the type of coffee processing method used is not relevant to the final chemical properties of the roasted coffee (i.e., the Castillo variety) evaluated in this study; the coffee cup score is also not affected, and the post-fermentation washing process can be dispensed with.Item Microorganisms in coffee fermentation: A bibliometric and systematic literature network analysis related to agriculture and beverage quality (1965-2019)(Editora UFLA, 2020) Cruz-O’Byrne, Rosmery; Piraneque-Gambasica, Nelson; Aguirre-Forero, Sonia; Ramirez-Vergara, JoseThe activity of microorganisms in coffee fermentation has a great influence on the composition of the beans and their beverage quality. In the present study, a bibliometric and systematic literature network analysis is made to examine the growth in the literature and the flow of knowledge in the field of study. The bibliometric information was retrieved from the Scopus database, obtaining 55 articles between 1965 and 2019. Frequencies, co-authorship, and co-occurrence indicators were analyzed using Microsoft Excel and VOSviewer software. Our findings show that most of the articles have been published in the last decade and mainly on microbial diversity and starter cultures. Furthermore, it was possible to identify the most productive authors, the most influential works, the main journals where articles of the most productive authors and the most influential works have been published, the most productive affiliation countries, the most used keywords, the co-authorship taking authors and countries as the unit of analysis, the keyword co-occurrence, and the spatial distribution of studies with their research topics. This is the first bibliometric and systematic literature network analysis carried out on research articles on microorganisms in coffee fermentation related to agriculture and beverage quality, which becomes a tool for researchers in making decisions for the building and development of strategic plans for future research by understanding the trends and status of existing research in the field of study in accordance with the authors, works, affiliation countries, study topics, and patterns of international collaboration and within the academic community.