Beneficiamento de sementes de café (Coffea arabica L.) e efeitos na qualidade
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2003
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A necessidade de obter melhores informações sobre o beneficiamento de sementes de café motivou a realização da presente pesquisa, cujos objetivos foram verificar a possibilidade de uso da máquina de ar e peneiras e da mesa de gravidade no fracionamento de lotes de sementes segundo características físicas e, paralelamente, estudar seus efeitos nas qualidades física e fisiológica das sementes. Um lote de sementes de café Catuaí Amarelo, linhagem IAC H 2077-2-5-62, foi beneficiado em máquina de pré-limpeza, em máquina de limpeza e classificação e em mesa de gravidade, de forma isolada ou em sequência, cujo o fluxo operacional deu origem a vinte tratamentos. Do lote original, devidamente homogeneizado, foi retirada uma porção de sementes que permaneceu sem nenhum tipo de manipulação, constituindo o tratamento "Sem Beneficiamento". Outra porção foi submetida ao processo de seleção manual, constituindo o tratamento "Escolha Manual", que foi considerado como testemunha. Em seguida, o restante do lote foi submetido à ação de uma máquina de pré-limpeza, onde a porção que ficou retida na peneira inferior, com orifícios oblongos de 9/64 x 3/4 de polegada, constituiu o tratamento "Pré Limpeza". Após isso, essa porção foi submetida à ação de uma mesa de gravidade com a região de descarga dividida em frações superior, intermediária-superior, intermediária-inferior e inferior, constituindo quatro tratamentos. Foi admitida como extremidade superior o ponto mais elevado da região de descarga, quando considerada a inclinação lateral da mesa de gravidade e, como inferior, a extremidade oposta. Essas quatro frações foram, posteriormente, reunidas e misturadas homogeneamente em uma só fração, reconstituindo, portanto, a porção "Pré Limpeza", que foi submetida à ação de uma máquina de limpeza e classificação, provida com peneiras de orifícios circulares e oblongos, intercaladas, obtendo-se cinco classes de tamanho nas pereiras 15/64 x ¾, 22/64, 13/64 x ¾ e 18/64 de polegada, constituindo os respectivos tratamentos desse equipamento. As sementes retidas nas peneiras 22/64 e 20/64 de polegada foram submetidas, separadamente, à ação de uma mesa de gravidade com as mesmas regulagens utilizadas anteriormente, obtendo-se quatro novas frações com pesos específicos distintos para cada uma das peneiras mencionadas, constituindo mais oito tratamentos e finalizando seqüência operacional do beneficiamento. Amostras de sementes foram coletadas a intervalos regulares de tempo a partir da estabilização do funcionamento dos equipamentos, dando origem às quatro repetições dos respectivos tratamentos. As amostras, embaladas em sacos de papel Kraft e colocadas dentro de vasilhames não herméticos, foram mantidas em ambiente de laboratório, sem controle de temperatura e de umidade relativa, sendo as sementes avaliadas quanto às suas características físicas e fisiológicas através de determinações em laboratório e casa de vegetação, aos zero, quatro e oito meses de armazenamento. A análise e interpretação dos resultados permitiram concluir que: a) A escolha manual de sementes de café permite a obtenção de lotes com qualidade fisiológica superior à do lote original, porém de forma menos eficiente que o beneficiamento mecanizado em máquina de ar e peneiras e mesa de gravidade; b) A máquina de pré-limpeza a máquina de ar e peneiras são eficientes para homogeneização do lote e classificação das sementes de café segundo a largura e espessura; c) A mesa da gravidade é eficiente para o fracionamento de lotes de sementes de café segundo o peso volumétrico e densidade das sementes; d) O beneficiamento de lotes de sementes de café em máquina de ar e peneiras e mesa de gravidade proporciona alterações favoráveis às características físicas e fisiológicas, onde as sementes de maior tamanho ou maior densidade apresentam desempenho fisiológico superior ao das sementes de menor tamanho ou menor densidade; e) O uso da mesa de gravidade, associado ou não à máquina de ar e peneiras, proporciona ganhos qualitativos aos lotes de sementes de café; f) As sementes mocas de café apresentam qualidade fisiológica similar à das sementes chatas.
The need of more suitable informations concerning processing of coffee seeds led to the present research whose objectives were to verify the poddibility of using the airscreen machine and the gravity table for dividing cofee lots into fraction according to physical characteristics and to study their effects on the physical and physiological quality of the seeds. A coffee seed lot of the Catuai Amarelo cultivar, line IAC H 2077-2-5-62 was processed in a precleaning machine, an air-screen machine and a gravity table, working isolated or in a sequence, whose operacional flow originated twenty treatments. From the original lot, properly homogeneized, a portion of seeds was removed and remained without any kind of handling, constituting the treatment "Original Material". Another portion was submitted to land selection, constituting the treatment "Hand Sorting", wich was considered the control. After that, the remaining of the original lot was conditioned through a precleaning machine (scalper) in wich the portion retained be the lower screen, with 9/64 x ¾ inch oblong holes, constituted the "Precleaning" treatment. Afterwards, this portion was sent through table with the discharge edge divided into fraction called upper, upperintermediate, lower-intermediater and lower, with different specific weights. It was regarde as upper end the highest spout of the discharge side, considering the lateral deck slope, and as lower spout the opposite end. Following that, these four fractions were put togheter and thoroughly mixed in just one fraction, so reconstituting the "Precleaning" portion, which was processed by an air-screen machine furnished with round or blong hole screens, obtaining five size classes with the use of screens inserted in following order, from top to botton: 15/64 x ¾, 22/64, 13/64 x ¾ and 18/64 inch. The seeds retained over the screens with 22/64 and 20/64 inch round holes of the airsecreen machine were processed, individually, by the gravity table, maintaining the same former adjustaments, obtaining in this way, four new factions with different specific weights by each of the two mentioned screens, so completing the operacional sequence and finishing the 4 application of the pertinent treatments. Seed samples related to the different treatments were collected at regular intervals after the equipament was operating in a steady, even flow in order to obtain the four replications. The samples, packed in Kraft paper bags and inside non airtight containers, were maintained under laboratory conditions, with no temperature and relative humidity control, and the seeds evaluated in laboratory and greenhouse, as to their physicalk and physiological quality, at zero, four and eight months of storage. The analysis and interpretation of the results allowed the following conclusions: a) Hand sorting favored the improvement of the coffee seed quality in relation to the original lot, though showing less efficienty than the mechanized processing in the air-screen machine and the gravity table; b) The precleaning machine and air-screen machine were effective for divicing coffee seeds into size homogeneous classes according to eidth and thickness seeds; c) The gravity table was effective for classifying coffee seeds according to volumetric wieght or density; d) The procesing by the air-screen machine and the gravity table favored the physical and physiological seed quality, in wich the fractions of larger size or higher density have presented performance physiological superior to the fractions of smaler size or lowest density; e) The use of the gravity table, individually or in combination with air-screen machine. Provided qualitive gains to the coffee seed lot; f) The oval seeds (moca) presented physiological quality similar to the normal seed (flat).
The need of more suitable informations concerning processing of coffee seeds led to the present research whose objectives were to verify the poddibility of using the airscreen machine and the gravity table for dividing cofee lots into fraction according to physical characteristics and to study their effects on the physical and physiological quality of the seeds. A coffee seed lot of the Catuai Amarelo cultivar, line IAC H 2077-2-5-62 was processed in a precleaning machine, an air-screen machine and a gravity table, working isolated or in a sequence, whose operacional flow originated twenty treatments. From the original lot, properly homogeneized, a portion of seeds was removed and remained without any kind of handling, constituting the treatment "Original Material". Another portion was submitted to land selection, constituting the treatment "Hand Sorting", wich was considered the control. After that, the remaining of the original lot was conditioned through a precleaning machine (scalper) in wich the portion retained be the lower screen, with 9/64 x ¾ inch oblong holes, constituted the "Precleaning" treatment. Afterwards, this portion was sent through table with the discharge edge divided into fraction called upper, upperintermediate, lower-intermediater and lower, with different specific weights. It was regarde as upper end the highest spout of the discharge side, considering the lateral deck slope, and as lower spout the opposite end. Following that, these four fractions were put togheter and thoroughly mixed in just one fraction, so reconstituting the "Precleaning" portion, which was processed by an air-screen machine furnished with round or blong hole screens, obtaining five size classes with the use of screens inserted in following order, from top to botton: 15/64 x ¾, 22/64, 13/64 x ¾ and 18/64 inch. The seeds retained over the screens with 22/64 and 20/64 inch round holes of the airsecreen machine were processed, individually, by the gravity table, maintaining the same former adjustaments, obtaining in this way, four new factions with different specific weights by each of the two mentioned screens, so completing the operacional sequence and finishing the 4 application of the pertinent treatments. Seed samples related to the different treatments were collected at regular intervals after the equipament was operating in a steady, even flow in order to obtain the four replications. The samples, packed in Kraft paper bags and inside non airtight containers, were maintained under laboratory conditions, with no temperature and relative humidity control, and the seeds evaluated in laboratory and greenhouse, as to their physicalk and physiological quality, at zero, four and eight months of storage. The analysis and interpretation of the results allowed the following conclusions: a) Hand sorting favored the improvement of the coffee seed quality in relation to the original lot, though showing less efficienty than the mechanized processing in the air-screen machine and the gravity table; b) The precleaning machine and air-screen machine were effective for divicing coffee seeds into size homogeneous classes according to eidth and thickness seeds; c) The gravity table was effective for classifying coffee seeds according to volumetric wieght or density; d) The procesing by the air-screen machine and the gravity table favored the physical and physiological seed quality, in wich the fractions of larger size or higher density have presented performance physiological superior to the fractions of smaler size or lowest density; e) The use of the gravity table, individually or in combination with air-screen machine. Provided qualitive gains to the coffee seed lot; f) The oval seeds (moca) presented physiological quality similar to the normal seed (flat).
Descrição
Tese de Doutorado defendida na null
Palavras-chave
Café Sementes Processamento Qualidade Coffea arabica, Coffee Seeds Processing Quality Air-screen machine Gravity table Coffea arabica
Citação
Giomo, Gerson Silva. Beneficiamento de sementes de café (Coffea arabica L.) e efeitos na qualidade. Botucatu, UNESP, Campus Botucatu, 2003. 100 fls. : il. (Tese - Doutorado em Agronomia) Orientador: João Nakagawa.