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Post-harvest processing (PHP) modifies the quality of the coffee and increases the value of coffee production. The choice of PHP to apply depends primarily on the available infrastructure, local climatic conditions and the desired end-value. The objective of this study was to evaluate the influence of PHP on the physico-chemical characteristics of green and roasted coffee beans and their sensory attributes. Coffee cherries from IAPAR 59 cultivar were processed as natural coffee (CN), semi-dry coffee (CD), de-pulped coffee (CP) and floating coffee (CF). Total and reducing sugars, phenolic compounds, chlorogenic acids, lipids, proteins, caffeine and water content were determined in coffee beans collected during (10thday) and at the end of each processing. The roasted beans and their sensory attributes were also analyzed. The greatest changes at the ending point of the processes were found in total and reducing sugars, phenolic compounds, chlorogenic acids and lipids contents. The PHP presented different weight loss to achieve the same visual brown color and luminosity. Beverage sensory attributes were influenced by the PHP: CN and CP coffees presented similar intensities of coffee aroma, but higher intensity of green grassy aroma, and taste were found in CF and CN coffees. Aroma and taste precursors were modified during the PHP and these were associated to husk removal of the coffee beans, suggesting an activation of the germination metabolism during the PHP. This study allowed the characterization of the effects of the different post-harvest processing on the roasted coffee beans and provides the foundations to monitor their efficiencies in the future.

This article contains data related to the research article entitled "Quantitative assessment of specific defects in roasted ground coffee via infrared-photoacoustic spectroscopy" (Dias et al., 2018). A method potentially able for assessing the quality of roasted ground coffees is described in the origin paper. Infrared spectroscopy and photoacoustic detection (FTIR-PAS) associated with multivariate calibration were used. The samples were obtained blending whole and healthy coffee beans (C. arabica and C. canephora) with specific blends of defects, named selections, which contain broken, sour, and black beans, skin, woods and healthy beans still not collected. In addition to a reduction in commercial value, the presence of defects compromises the sensory attributes of coffee. On the other hand, selections are commonly found in coffee crops and can be added intentionally to the product. Twenty-five selections were used to obtain a panel of 154 blends. The FTIR-PAS spectra of each sample generated the prediction model of Partial Least Squares Regression parameters, which are also presented here.

The exploration of accessions originating from Ethiopia is one option available to increase the genetic basis of new coffee cultivars. The aim of this study was to describe the chemical composition variability of Ethiopian coffee accessions maintained in Londrina and to evaluate the year effect on that. We observed no significant interaction between the years of cultivation and the amounts of caffeine, protein, lipids, chlorogenic acids, sucrose, cafestol and kahweol, thereby suggesting that evaluations of one year were reliable to describe this collection. All compounds showed variability, but the highest variability was found in cafestol and kahweol (32.81 and 34.45 %, respectively). Significant correlations among caffeine, chlorogenic acids and protein as well as between sucrose and lipids were observed. A significant negative correlation was found between kahweol and cafestol, and kahweol had positive and negative correlation with caffeine and chlorogenic acids, respectively. Hierarchical clustering analyses identified groups in the population, and the diversity found in one crop year was similar to that for 3 years. Greater diversity of composition was observed among the Western accessions compared to the ones from the East, but no clear separation was found between the accessions of these regions. These accessions are potential sources to increase the genetic diversity to obtain new coffee cultivars. (Résumé d'auteur)