Aldir Alves Teixeira

Use of Excelsa coffee in blends with Arabica

Among the known coffee species only Coflea arabica (Arabica coffee) and C. canephora (Robusta coffee) have economic importance in international market Excelsa coffee (C.dewevrei cv.Excelsa) in spite of its rusticity, high yielding capacity and normal sized grains is not yet cultivated in any producing country. Therefore there is little information on its cupping quality. In order to pursue this, pure Excelsa coffee and blends of it with Arabica of good cup quality were analysed. An incomplete balanced design was used with eight entries, seven replications besides an additional control of soft Arabica as standard. A six-point scale (0 = rio; 5 = mild) routinely used for classification of pure Arabica coffee samples was used in the trial. During roasting operation the Excelsa samples developed a distinct, unpleasant aroma. Three panelist experts analysed all coffee samples. The standard Arabica samples received an average of 3.76 points, similar to that of the control mild Arabica, with 3.86 points. Excelsa pure coffee sample was graded an average of 1.64 point The average points given to the blends corresponding to 10, 20, 30, 40 and 50% of Excelsa were 3.23, 2.95, 2.91, 267, and 1.91 respectively. The experts reported 85.7% of the pure Excelsa samples as having unusual taste. A significant positive correlation (r = 0.91) was found between increased proportion of Excelsa in the blends and the abnormal taste of the liquor. It was observed a variability in the ability of the experts to recognize the Excelsa taste. A negative significant (r =-0.93) correlation was found between the increased percentage of Excelsa in the blends and the liquor point average. It is concluded that up to 23% of Excelsa coffee can be blended with mild Arabica without major changes in the cupping quality.

Avaliação da bebida e outras características de cultivares de Coffea canephora e Coffea congensis

Analisaram-se varias caracteristicas morfologicas de amostras de sementes e a qualidade do produto de alguns cultivares de Coffea canephora e de C. congensis, coletadas em quatro localidades do Estado de Sao Paulo. Utilizou-se uma escala de cinco pontos, desenvolvida em Angola, para avaliacao da qualidade da bebida de C. canephora. Os dados obtidos foram comparados com os dos padroes kouillou de C. canephora do Estado do Espirito Santo e mundo-novo de C. arabica. Verificou-se que 46% das amostras de sementes beneficiadas foram classificadas como pertencentes a C. arabica e, 36%, a C. canephora. As porcentagens de sementes do tipo moca variaram de 10 a 50% para as amostras de C. canephora e de 20 a 40% para C. congensis. Para o mundo-novo essa porcentagem foi de 15%. Os dados referentes a qualidade da bebida indicaram que oito amostras deram bebida significativamente melhor do que a do padrao kouillou e nenhuma se revelou melhor do que a do mundo-novo. Comparacoes entre as medias de pontos conferidos a bebida de 17 amostras de C. canephora despolpadas com as correspondentes nao despolpadas, revelaram diferencas significativas, indicando que a operacao do despolpamento contribuiu para a melhoria da qualidade da bebida. As amostras de cafe despolpadas de C. canephora colhidas em Ribeirao Preto revelaram-se de melhor qualidade de bebida, em relacao as das outras tres localidades: Tiete, Jau e Pindorama. Os dados obtidos evidenciaram, ainda, que os cultivares de C. congensis e de C. canephora podem dar bebida de qualidade semelhante.

Qualidade da bebida do café: efeito do acondicionamento e do tempo de conservação

O efeito do tempo de armazenamento sobre a qualidade da bebida de cafe do cultivar mundo novo de Coffea arabica foi estudado em Campinas, no periodo de junho de 1974 a marco de 1976. Planejou-se o delineamento em blocos ao acaso para as amostras, sendo analisada a bebida do cafe despolpado e beneficiado conservado em latas hermeticamente fechadas, em sacos de plastico, de aniagem, de tecido de algodao e de papel. Para os testes de bebida adotou-se o delineamento de blocos ao acaso. Tres series de amostras foram retiradas 5, 16 e 21 meses, apos o inicio do experimento e analisadas quanto a qualidade da bebida, usando-se a escala de 0-5 pontos, normalmente empregada para essas avaliacoes. Nao se notaram efeitos de embalagem nas amostras analisadas na primeira epoca, tendo as medias de pontos variado de 3,2 a 3,3. Para a segunda e terceira epocas, notaram-se diferencas significativas, sendo obtidas medias de pontos maiores nas amostras conservadas em latas e em sacos de plastico, que constituem as melhores embalagens. O tempo de armazenamento influiu desfavoravelmente para os tratamentos. Quanto a cor dos graos, as amostras conservadas em latas e em sacos de plastico revelaram-se inalteradas, enquanto as demais pioraram, tornando-se esbranquicadas. O teor de umidade revelou-se menor nas latas e nos sacos plasticos, bem como os valores da peneira media. Nessas embalagens observou-se maior peso de sementes de algumas peneiras.

Grãos defeituosos em café colhido verde

The frequency of defective coffee beans was determined in samples of unripe fruits of the cultivar Mundo Novo (Coffea arabica).Ten samples of 1000 seeds each obtained from green fruits after sundrying and shelling were independently scored for the commercial defects by three coffee classifiers. Each one of the classifiers recorded the occurrence of green-coated, brown and black beans before and after removal of the silver skin. The data revealed that more than half of the beans had normal green color whereas 44.9 per cent were green-coated, 3.5 per cent were brown and 0.1 per cent were black beans. The removal of the silver skin affected the previous classification giving 59.7 per cent of normal green beans, 39.5 per cent of brown and 0.3 per cent of black beans. These observations indicated that the so-called green-coated beans are caused by the presence of the silver skin which retains green pigments probably chlorophyll. On the other hand the browns which have been considered as product of over-fermentation were scored in a much higher frequency whereas the percentage of black beans was little altered after the removal of the silver skin. The factors responsible for origin of the brown and black beans are discussed. Preliminary studies of the cup quality of the normal green beans selected from these samples indicated that the quality of the beverage had the poor taste characteristic of unripe coffee despite of the appearance of the beans.

Qualidade da bebida em espécies e populações derivadas de híbridos interespecíficos de Coffea

Investigations on coffee cupping quality of the species C. canephora, C. congensis and several populations derived from interespecific crosses (C. canephora dp x C. arabica, C. canephora x C. eugenioides, C. arabica x C. dewevrei dp and C. racemosa x C. arabica) were undertaken in two trials, in order to guide breeding programs using this germoplasm. Two grading systems were used for classification of the cupping quality, the normal six points scale used for C. arabica samples and a new one with 10 points, 1 for the lowest and 10 for the highest quality. Coffee liquorer experts graded the overall cupping quality and added remarks to any unpleasant taste noticed in the samples. The analysis of the data pointed out that both scales were not adequate for a complete characterization and discrimination of the individual samples. When coffee samples ware grouped according to the species involved in the crosses, the results indicated the superiority of the C. arabica x C, dewevrei dp and C. canephora dp x C. arabica groups in the first trial. In the second trial the C. racemosa x C. arabica group revealed the best average cupping quality, statistically superior to C. canephora and C. congensis. Most of the non-commercial coffees displayed unique tastes and were characterized in 13 unpleasant types. Due to the inherent diversity of the analysed material the liquorer experts had difficulty in classifying the several abnormal tastes influencing the classification of the mild standard sample. The results indicated the necessity of more accurate studies of the beverage produced by these species mainly when they participate in the breeding of Arabica coffee.