Coffea arabica

Habita entre los 1000 y los 2000 msnm, en Colombia, puede encontrarse a mayor o menor altura

Sumber: Flora del Tolima presente en las cuencas hidrográficas de los ríos Coello, Totare, Recio, Lagunilla, Amoyá, Anamichú, Mendarco, Prado y quebrada Guanábano.

In order to assess the antioxidant capacity of the green coffee extracts, we evaluated their reducing power by ferric thiocyanate assay and the free radical scavenging activities by DPPH radical assay. In general, the extracts were more active as antioxidants when tested by the reducing power assay (Fig. 5), since the steric accessibility of DPPH nitrogen-centered radical strongly affects the reaction rate of antioxidant compounds (Prior et al., 2005). Fig. 5 depicts the scatter plot of IC 50 values from both tests. As expected, the four C. canephora accessions showed the highest antioxidant activity (lowest IC 50 values for both assays) with respect to all other accessions. Although weaker than chlorogenic acid (Zhao et al., 2015), caffeine as well possesses antioxidant capacity, as recently demonstrated in in vivo experiments (Tsoi et al., 2015). Therefore, the higher content of both chlorogenic acids and caffeine correlates with a higher antioxidant capacity. Among the C. arabica accessions, the samples from Kenya showed the highest antioxidant capacity, followed by one of the accessions from Peru (A-Peru 2) and one from Honduras (A-Honduras 2). The lowest antioxidant capacity was observed in the Ethiopian (A-Ethiopia) and Guatemala (A-Guatemala) accessions, whereas intermediate antioxidant activities were observed for the remaining green coffee accessions.

Sumber: Chemical partitioning and antioxidant capacity of green coffee (Coffea arabica and Coffea canephora) of different geographical origin

Different classes of compounds have been used for the authentication of different coffee varieties (Alonso-Salces et al., 2009 and references cited therein) and for distinguishing the species and origins of green coffee bean samples of C. arabica and C. canephora from different geographic regions (Rodrigues et al., 2009; Sberveglieri et al., 2011; Serra et al., 2005; Wei et al., 2012). We used the data set of Table 1 to calculate a Principal Component Analysis (PCA). Fig. 4 shows the scatter plot of the two main PCA factor loadings, which explained the 96 % and 3 % of the total variance for Factor 1 and Factor 2, respectively. A discrimination between the C. canephora accessions and all other C. arabica species was observed, mainly because of Factor 2 scores (negative for C. canephora and positive for C. arabica). Among C. arabica, a separation was found for C. arabica from Kenya and all other accessions, which were separated by positive values of Factor 1. A separation was also observed for the ‘‘ caracol ” accession from Brasil (C-Brasil). The ‘‘ caracol ” (or ‘‘ snail ” in Spanish, also called peaberry) is a natural mutation of the C. canephora coffee bean inside its cherry that affects about 5 % of the world coffee. The phenotype of these ‘‘ caracol ” green coffee produces a single, rather than a double bean that appears smaller, denser and with a more rounded shape with respect to the wild type (Cilas and Bouharmont, 2005; Giomo et al., 2008). As expected, the chemical pattern of the C-Brasil accession places it closer to the C. canephora group (Fig. 4). A cluster analysis (CA) calculated on the data matrix of Table 1, by using Euclidean distance with median linkage method, shows a first cluster that isolates the A-Kenya accessions because of the higher content of neochlorogenic acid (5). A second cluster is made by all C. canephora accessions, with a close statistical linkage between R-Vietnam 1 and R-Vietnam 2. This cluster is generated because of the high amount of caffeine (16). A third cluster isolates the C-Brasil accession because of the presence of 4 - O-feruloyl- 5 - caffeoylquinic acid (15), whereas a fourth cluster gathers the APeru 1 accession containing a higher content of caffeic acid (1). All other C. arabica accessions are present in the last cluster because of the high amount of chlorogenic acids. Several subclusters compose this last cluster (see Supplementary Fig. S 1).

Sumber: Chemical partitioning and antioxidant capacity of green coffee (Coffea arabica and Coffea canephora) of different geographical origin