Composição química de cafés árabica de cultivares tradicionais e modernas

Abstract

Resumo -O objetivo deste trabalho foi avaliar a influência da diversidade genética sobre a composição química de cultivares modernas e tradicionais de café arábica brasileiro. Cultivares tradicionais (Bourbon, Catuaí e Icatu) e modernas (Iapar 59, IPR 98, IPR 99 e IPR 103) foram cultivadas nas mesmas condições edafoclimáticas e submetidas a tratamentos pós-colheita padronizados. Determinaram-se os teores de sacarose, açúcares redutores, ácidos orgânicos (quínico, málico e cítrico), compostos fenólicos totais, ácido 5-cafeoilquínico, compostos nitrogenados (proteína, trigonelina e cafeína), lipídeos totais, cafestol e caveol. A diversidade genética confere variabilidade à composição do café e permite a discriminação entre cultivares tradicionais e modernas. As cultivares modernas apresentam maior teor de ácidos málico e 5-cafeoilquínico, lipídeos totais, caveol e trigonelina. Os parâmetros caveol e a relação caveol/ cafestol são propostos como discriminadores entre cultivares modernas e tradicionais, uma vez que a introgressão de genes de Coffea canephora aumenta os teores de caveol e os valores da relação caveol/cafestol.Termos para indexação: Coffea arabica, Coffea canephora, café cru, compostos bioativos, diversidade genética, diterpenos. Chemical composition of traditional and modern Arabica coffee cultivarsAbstract -The objective of this work was to evaluate the influence of genetic diversity on the chemical composition of traditional and modern cultivars of Brazilian arabica coffee. Traditional (Bourbon, Catuaí and Icatu) and modern cultivars (Iapar 59, IPR 98, IPR 99, and IPR 103) were subjected to the same edaphoclimatic conditions, and to standardized post-harvest treatments. Contents of sucrose, reducing sugars, organic acids (quinic, malic, and citric), total phenolic compounds, 5-caffeoylquinic acid, nitrogenous compounds (protein, caffeine, and trigonelline), total lipids, cafestol, and kahweol were determined. Genetic diversity provides variability in coffee composition, allowing the discrimination between traditional and modern cultivars. Modern cultivars have higher contents of malic and 5-caffeoylquinic acids, total lipids, kahweol and trigonelline. The parameters kahweol and the kahweol/cafestol ratio are proposed as discriminators between traditional and modern cultivars, since the introgression of genes from Coffea canephora increase the kahweol content and the values of kahweol/cafestol ratio.

Production, chemical composition, and quality of Arabic coffee subjected to copper doses

“…The maximum concentrations of citric and malic acids found in the present study are close to those of 1.12 and 0.33%, respectively, reported by Kitzberger et al (2013) for cherry beans of 'Catuaí Vermelho IAC 81'. It should be noted that organic acids are non-volatile components of coffee acidity and that malic and citric acids have been associated with a good quality beverage (Carvalho et al, 1997).…”

“…The increase in Cu doses promoted a decline, followed by a subsequent increase in phenolic contents, which fitted to the quadratic model, with the lowest content of 6.10% at the estimated dose of 1.55 μmol L -1 and 8.05 mg kg -1 Cu leaf content (Figure 3). The lowest phenolic content found by Kitzberger et al (2013) was 4.55% in cherries of 'Catuaí Vermelho IAC 86' cultivated in the field. The reduction in phenolic content with higher Cu doses is directly related to the role of Cu in the secondary plant metabolism, i.e., in the lignification and formation of melanocytic substances, since the enzymes that oxidize phenols into lignin and other compounds are activated by Cu.…”

“…The contents of caffeine, trigonelline, and proanthocyanidins were not affected by Cu doses, and showed means ranging from 1.30 to 1.47 g 100 g -1 , 0.86 to 1.10 g 100 g -1 , and 6.17 to 6.26 mg g -1 , respectively (Table 2). While evaluating 'Catuaí Vermelho IAC 86', Kitzberger et al (2013) found similar contents for caffeine, the main bitter compound in coffee, and for trigonelline, which degrades into volatile compounds responsible for the aroma during roasting (Farah et al, 2006). In the present study, the accumulation of proanthocyanidins, which are compounds partially responsible for the astringency in coffee, was higher than the concentrations between 3.47 and 5.48 g 100 g -1 reported by Morais et al (2009) for 'Conilon' Coffea canephora Pierre ex A.Froehner.…”

“…The chemical composition, and qualitative and quantitative variations of coffee beans were investigated according to species (Monteiro & Farah, 2012), cultivar (Kitzberger et al, 2013), and also to processing, growing environment, and management (Ribeiro et al, 2016). Among the chemical components of the raw coffee beans, chlorogenic acids, caffeine, trigonelline, phenols, and sucrose are closely related to the sensory quality of the beverage and are used in its classification (Farah et al, 2006).…”

Instant coffee with steamed PVA beans: Physical-chemical and sensory aspects

“…For the analysis of the bioactive compounds in raw coffees, extraction was carried out based on Kitzberger et al (2013). Samples (0.50 g) were extracted with 50 mL of boiling water, for 45 min.…”